diff --git a/packages/devextreme-angular/src/ui/accordion/index.ts b/packages/devextreme-angular/src/ui/accordion/index.ts
index 1118a8f0dc0a..7369e90a8cfd 100644
--- a/packages/devextreme-angular/src/ui/accordion/index.ts
+++ b/packages/devextreme-angular/src/ui/accordion/index.ts
@@ -287,10 +287,10 @@ export class DxAccordionComponent<TItem = any, TKey = any> extends DxComponent i
     
      */
     @Input()
-    get keyExpr(): Function | string {
+    get keyExpr(): ((item: any) => any) | string {
         return this._getOption('keyExpr');
     }
-    set keyExpr(value: Function | string) {
+    set keyExpr(value: ((item: any) => any) | string) {
         this._setOption('keyExpr', value);
     }
 
@@ -634,7 +634,7 @@ export class DxAccordionComponent<TItem = any, TKey = any> extends DxComponent i
      * This member supports the internal infrastructure and is not intended to be used directly from your code.
     
      */
-    @Output() keyExprChange: EventEmitter<Function | string>;
+    @Output() keyExprChange: EventEmitter<((item: any) => any) | string>;
 
     /**
     
diff --git a/packages/devextreme-angular/src/ui/button-group/index.ts b/packages/devextreme-angular/src/ui/button-group/index.ts
index ff3575b1baaf..ffa2dd3715ad 100644
--- a/packages/devextreme-angular/src/ui/button-group/index.ts
+++ b/packages/devextreme-angular/src/ui/button-group/index.ts
@@ -207,10 +207,10 @@ export class DxButtonGroupComponent extends DxComponent implements OnDestroy, On
     
      */
     @Input()
-    get keyExpr(): Function | string {
+    get keyExpr(): ((item: any) => any) | string {
         return this._getOption('keyExpr');
     }
-    set keyExpr(value: Function | string) {
+    set keyExpr(value: ((item: any) => any) | string) {
         this._setOption('keyExpr', value);
     }
 
@@ -441,7 +441,7 @@ export class DxButtonGroupComponent extends DxComponent implements OnDestroy, On
      * This member supports the internal infrastructure and is not intended to be used directly from your code.
     
      */
-    @Output() keyExprChange: EventEmitter<Function | string>;
+    @Output() keyExprChange: EventEmitter<((item: any) => any) | string>;
 
     /**
     
diff --git a/packages/devextreme-angular/src/ui/card-view/nested/tab-panel-options.ts b/packages/devextreme-angular/src/ui/card-view/nested/tab-panel-options.ts
index d6c289986e51..e14a74b65c55 100644
--- a/packages/devextreme-angular/src/ui/card-view/nested/tab-panel-options.ts
+++ b/packages/devextreme-angular/src/ui/card-view/nested/tab-panel-options.ts
@@ -176,10 +176,10 @@ export class DxoCardViewTabPanelOptionsComponent extends NestedOption implements
     }
 
     @Input()
-    get keyExpr(): Function | string {
+    get keyExpr(): ((item: any) => any) | string {
         return this._getOption('keyExpr');
     }
-    set keyExpr(value: Function | string) {
+    set keyExpr(value: ((item: any) => any) | string) {
         this._setOption('keyExpr', value);
     }
 
diff --git a/packages/devextreme-angular/src/ui/chat/nested/suggestions.ts b/packages/devextreme-angular/src/ui/chat/nested/suggestions.ts
index b273036e1f95..9f72a9b4ed56 100644
--- a/packages/devextreme-angular/src/ui/chat/nested/suggestions.ts
+++ b/packages/devextreme-angular/src/ui/chat/nested/suggestions.ts
@@ -126,10 +126,10 @@ export class DxoChatSuggestionsComponent extends NestedOption implements OnDestr
     }
 
     @Input()
-    get keyExpr(): Function | string {
+    get keyExpr(): ((item: any) => any) | string {
         return this._getOption('keyExpr');
     }
-    set keyExpr(value: Function | string) {
+    set keyExpr(value: ((item: any) => any) | string) {
         this._setOption('keyExpr', value);
     }
 
diff --git a/packages/devextreme-angular/src/ui/context-menu/index.ts b/packages/devextreme-angular/src/ui/context-menu/index.ts
index 0ee0497bfd0b..b5739b849ed0 100644
--- a/packages/devextreme-angular/src/ui/context-menu/index.ts
+++ b/packages/devextreme-angular/src/ui/context-menu/index.ts
@@ -188,10 +188,10 @@ export class DxContextMenuComponent<TItem = any, TKey = any> extends DxComponent
     
      */
     @Input()
-    get disabledExpr(): Function | string {
+    get disabledExpr(): ((item: any) => boolean | undefined) | string {
         return this._getOption('disabledExpr');
     }
-    set disabledExpr(value: Function | string) {
+    set disabledExpr(value: ((item: any) => boolean | undefined) | string) {
         this._setOption('disabledExpr', value);
     }
 
@@ -305,10 +305,10 @@ export class DxContextMenuComponent<TItem = any, TKey = any> extends DxComponent
     
      */
     @Input()
-    get itemsExpr(): Function | string {
+    get itemsExpr(): ((item: any) => Array<any> | undefined) | string {
         return this._getOption('itemsExpr');
     }
-    set itemsExpr(value: Function | string) {
+    set itemsExpr(value: ((item: any) => Array<any> | undefined) | string) {
         this._setOption('itemsExpr', value);
     }
 
@@ -370,10 +370,10 @@ export class DxContextMenuComponent<TItem = any, TKey = any> extends DxComponent
     
      */
     @Input()
-    get selectedExpr(): Function | string {
+    get selectedExpr(): ((item: any, value: boolean | undefined) => boolean | undefined) | string {
         return this._getOption('selectedExpr');
     }
-    set selectedExpr(value: Function | string) {
+    set selectedExpr(value: ((item: any, value: boolean | undefined) => boolean | undefined) | string) {
         this._setOption('selectedExpr', value);
     }
 
@@ -645,7 +645,7 @@ export class DxContextMenuComponent<TItem = any, TKey = any> extends DxComponent
      * This member supports the internal infrastructure and is not intended to be used directly from your code.
     
      */
-    @Output() disabledExprChange: EventEmitter<Function | string>;
+    @Output() disabledExprChange: EventEmitter<((item: any) => boolean | undefined) | string>;
 
     /**
     
@@ -708,7 +708,7 @@ export class DxContextMenuComponent<TItem = any, TKey = any> extends DxComponent
      * This member supports the internal infrastructure and is not intended to be used directly from your code.
     
      */
-    @Output() itemsExprChange: EventEmitter<Function | string>;
+    @Output() itemsExprChange: EventEmitter<((item: any) => Array<any> | undefined) | string>;
 
     /**
     
@@ -743,7 +743,7 @@ export class DxContextMenuComponent<TItem = any, TKey = any> extends DxComponent
      * This member supports the internal infrastructure and is not intended to be used directly from your code.
     
      */
-    @Output() selectedExprChange: EventEmitter<Function | string>;
+    @Output() selectedExprChange: EventEmitter<((item: any, value: boolean | undefined) => boolean | undefined) | string>;
 
     /**
     
diff --git a/packages/devextreme-angular/src/ui/data-grid/nested/tab-panel-options.ts b/packages/devextreme-angular/src/ui/data-grid/nested/tab-panel-options.ts
index f6d00d1b2a34..98901506fe79 100644
--- a/packages/devextreme-angular/src/ui/data-grid/nested/tab-panel-options.ts
+++ b/packages/devextreme-angular/src/ui/data-grid/nested/tab-panel-options.ts
@@ -176,10 +176,10 @@ export class DxoDataGridTabPanelOptionsComponent extends NestedOption implements
     }
 
     @Input()
-    get keyExpr(): Function | string {
+    get keyExpr(): ((item: any) => any) | string {
         return this._getOption('keyExpr');
     }
-    set keyExpr(value: Function | string) {
+    set keyExpr(value: ((item: any) => any) | string) {
         this._setOption('keyExpr', value);
     }
 
diff --git a/packages/devextreme-angular/src/ui/form/nested/tab-panel-options.ts b/packages/devextreme-angular/src/ui/form/nested/tab-panel-options.ts
index d50c3a35c333..2524037aebe1 100644
--- a/packages/devextreme-angular/src/ui/form/nested/tab-panel-options.ts
+++ b/packages/devextreme-angular/src/ui/form/nested/tab-panel-options.ts
@@ -176,10 +176,10 @@ export class DxoFormTabPanelOptionsComponent extends NestedOption implements OnD
     }
 
     @Input()
-    get keyExpr(): Function | string {
+    get keyExpr(): ((item: any) => any) | string {
         return this._getOption('keyExpr');
     }
-    set keyExpr(value: Function | string) {
+    set keyExpr(value: ((item: any) => any) | string) {
         this._setOption('keyExpr', value);
     }
 
diff --git a/packages/devextreme-angular/src/ui/gantt/index.ts b/packages/devextreme-angular/src/ui/gantt/index.ts
index fc033a95310b..ee06dd58f3fa 100644
--- a/packages/devextreme-angular/src/ui/gantt/index.ts
+++ b/packages/devextreme-angular/src/ui/gantt/index.ts
@@ -199,10 +199,10 @@ export class DxGanttComponent extends DxComponent implements OnDestroy, OnChange
     
      */
     @Input()
-    get dependencies(): { dataSource?: Array<any> | DataSource | DataSourceOptions | null | Store | string, keyExpr?: Function | string, predecessorIdExpr?: Function | string, successorIdExpr?: Function | string, typeExpr?: Function | string } {
+    get dependencies(): { dataSource?: Array<any> | DataSource | DataSourceOptions | null | Store | string, keyExpr?: ((dependency: any) => any) | string, predecessorIdExpr?: ((dependency: any, value: any) => any) | string, successorIdExpr?: ((dependency: any, value: any) => any) | string, typeExpr?: ((dependency: any, value: any) => any) | string } {
         return this._getOption('dependencies');
     }
-    set dependencies(value: { dataSource?: Array<any> | DataSource | DataSourceOptions | null | Store | string, keyExpr?: Function | string, predecessorIdExpr?: Function | string, successorIdExpr?: Function | string, typeExpr?: Function | string }) {
+    set dependencies(value: { dataSource?: Array<any> | DataSource | DataSourceOptions | null | Store | string, keyExpr?: ((dependency: any) => any) | string, predecessorIdExpr?: ((dependency: any, value: any) => any) | string, successorIdExpr?: ((dependency: any, value: any) => any) | string, typeExpr?: ((dependency: any, value: any) => any) | string }) {
         this._setOption('dependencies', value);
     }
 
@@ -355,10 +355,10 @@ export class DxGanttComponent extends DxComponent implements OnDestroy, OnChange
     
      */
     @Input()
-    get resourceAssignments(): { dataSource?: Array<any> | DataSource | DataSourceOptions | null | Store | string, keyExpr?: Function | string, resourceIdExpr?: Function | string, taskIdExpr?: Function | string } {
+    get resourceAssignments(): { dataSource?: Array<any> | DataSource | DataSourceOptions | null | Store | string, keyExpr?: ((resourceAssignment: any) => any) | string, resourceIdExpr?: ((resourceAssignment: any, value: any) => any) | string, taskIdExpr?: ((resourceAssignment: any, value: any) => any) | string } {
         return this._getOption('resourceAssignments');
     }
-    set resourceAssignments(value: { dataSource?: Array<any> | DataSource | DataSourceOptions | null | Store | string, keyExpr?: Function | string, resourceIdExpr?: Function | string, taskIdExpr?: Function | string }) {
+    set resourceAssignments(value: { dataSource?: Array<any> | DataSource | DataSourceOptions | null | Store | string, keyExpr?: ((resourceAssignment: any) => any) | string, resourceIdExpr?: ((resourceAssignment: any, value: any) => any) | string, taskIdExpr?: ((resourceAssignment: any, value: any) => any) | string }) {
         this._setOption('resourceAssignments', value);
     }
 
@@ -368,10 +368,10 @@ export class DxGanttComponent extends DxComponent implements OnDestroy, OnChange
     
      */
     @Input()
-    get resources(): { colorExpr?: Function | string, dataSource?: Array<any> | DataSource | DataSourceOptions | null | Store | string, keyExpr?: Function | string, textExpr?: Function | string } {
+    get resources(): { colorExpr?: ((resource: any, value: any) => any) | string, dataSource?: Array<any> | DataSource | DataSourceOptions | null | Store | string, keyExpr?: ((resource: any) => any) | string, textExpr?: ((resource: any, value: any) => string) | string } {
         return this._getOption('resources');
     }
-    set resources(value: { colorExpr?: Function | string, dataSource?: Array<any> | DataSource | DataSourceOptions | null | Store | string, keyExpr?: Function | string, textExpr?: Function | string }) {
+    set resources(value: { colorExpr?: ((resource: any, value: any) => any) | string, dataSource?: Array<any> | DataSource | DataSourceOptions | null | Store | string, keyExpr?: ((resource: any) => any) | string, textExpr?: ((resource: any, value: any) => string) | string }) {
         this._setOption('resources', value);
     }
 
@@ -563,10 +563,10 @@ export class DxGanttComponent extends DxComponent implements OnDestroy, OnChange
     
      */
     @Input()
-    get tasks(): { colorExpr?: Function | string, dataSource?: Array<any> | DataSource | DataSourceOptions | null | Store | string, endExpr?: Function | string, keyExpr?: Function | string, parentIdExpr?: Function | string, progressExpr?: Function | string, startExpr?: Function | string, titleExpr?: Function | string } {
+    get tasks(): { colorExpr?: ((task: any, value: any) => any) | string, dataSource?: Array<any> | DataSource | DataSourceOptions | null | Store | string, endExpr?: ((task: any, value: any) => any) | string, keyExpr?: ((task: any) => any) | string, parentIdExpr?: ((task: any, value: any) => any) | string, progressExpr?: ((task: any, value: any) => any) | string, startExpr?: ((task: any, value: any) => any) | string, titleExpr?: ((task: any, value: any) => any) | string } {
         return this._getOption('tasks');
     }
-    set tasks(value: { colorExpr?: Function | string, dataSource?: Array<any> | DataSource | DataSourceOptions | null | Store | string, endExpr?: Function | string, keyExpr?: Function | string, parentIdExpr?: Function | string, progressExpr?: Function | string, startExpr?: Function | string, titleExpr?: Function | string }) {
+    set tasks(value: { colorExpr?: ((task: any, value: any) => any) | string, dataSource?: Array<any> | DataSource | DataSourceOptions | null | Store | string, endExpr?: ((task: any, value: any) => any) | string, keyExpr?: ((task: any) => any) | string, parentIdExpr?: ((task: any, value: any) => any) | string, progressExpr?: ((task: any, value: any) => any) | string, startExpr?: ((task: any, value: any) => any) | string, titleExpr?: ((task: any, value: any) => any) | string }) {
         this._setOption('tasks', value);
     }
 
@@ -949,7 +949,7 @@ export class DxGanttComponent extends DxComponent implements OnDestroy, OnChange
      * This member supports the internal infrastructure and is not intended to be used directly from your code.
     
      */
-    @Output() dependenciesChange: EventEmitter<{ dataSource?: Array<any> | DataSource | DataSourceOptions | null | Store | string, keyExpr?: Function | string, predecessorIdExpr?: Function | string, successorIdExpr?: Function | string, typeExpr?: Function | string }>;
+    @Output() dependenciesChange: EventEmitter<{ dataSource?: Array<any> | DataSource | DataSourceOptions | null | Store | string, keyExpr?: ((dependency: any) => any) | string, predecessorIdExpr?: ((dependency: any, value: any) => any) | string, successorIdExpr?: ((dependency: any, value: any) => any) | string, typeExpr?: ((dependency: any, value: any) => any) | string }>;
 
     /**
     
@@ -1033,14 +1033,14 @@ export class DxGanttComponent extends DxComponent implements OnDestroy, OnChange
      * This member supports the internal infrastructure and is not intended to be used directly from your code.
     
      */
-    @Output() resourceAssignmentsChange: EventEmitter<{ dataSource?: Array<any> | DataSource | DataSourceOptions | null | Store | string, keyExpr?: Function | string, resourceIdExpr?: Function | string, taskIdExpr?: Function | string }>;
+    @Output() resourceAssignmentsChange: EventEmitter<{ dataSource?: Array<any> | DataSource | DataSourceOptions | null | Store | string, keyExpr?: ((resourceAssignment: any) => any) | string, resourceIdExpr?: ((resourceAssignment: any, value: any) => any) | string, taskIdExpr?: ((resourceAssignment: any, value: any) => any) | string }>;
 
     /**
     
      * This member supports the internal infrastructure and is not intended to be used directly from your code.
     
      */
-    @Output() resourcesChange: EventEmitter<{ colorExpr?: Function | string, dataSource?: Array<any> | DataSource | DataSourceOptions | null | Store | string, keyExpr?: Function | string, textExpr?: Function | string }>;
+    @Output() resourcesChange: EventEmitter<{ colorExpr?: ((resource: any, value: any) => any) | string, dataSource?: Array<any> | DataSource | DataSourceOptions | null | Store | string, keyExpr?: ((resource: any) => any) | string, textExpr?: ((resource: any, value: any) => string) | string }>;
 
     /**
     
@@ -1145,7 +1145,7 @@ export class DxGanttComponent extends DxComponent implements OnDestroy, OnChange
      * This member supports the internal infrastructure and is not intended to be used directly from your code.
     
      */
-    @Output() tasksChange: EventEmitter<{ colorExpr?: Function | string, dataSource?: Array<any> | DataSource | DataSourceOptions | null | Store | string, endExpr?: Function | string, keyExpr?: Function | string, parentIdExpr?: Function | string, progressExpr?: Function | string, startExpr?: Function | string, titleExpr?: Function | string }>;
+    @Output() tasksChange: EventEmitter<{ colorExpr?: ((task: any, value: any) => any) | string, dataSource?: Array<any> | DataSource | DataSourceOptions | null | Store | string, endExpr?: ((task: any, value: any) => any) | string, keyExpr?: ((task: any) => any) | string, parentIdExpr?: ((task: any, value: any) => any) | string, progressExpr?: ((task: any, value: any) => any) | string, startExpr?: ((task: any, value: any) => any) | string, titleExpr?: ((task: any, value: any) => any) | string }>;
 
     /**
     
diff --git a/packages/devextreme-angular/src/ui/gantt/nested/dependencies.ts b/packages/devextreme-angular/src/ui/gantt/nested/dependencies.ts
index b6b1ce6b8c0e..4b2a44d5517d 100644
--- a/packages/devextreme-angular/src/ui/gantt/nested/dependencies.ts
+++ b/packages/devextreme-angular/src/ui/gantt/nested/dependencies.ts
@@ -41,34 +41,34 @@ export class DxoGanttDependenciesComponent extends NestedOption implements OnDes
     }
 
     @Input()
-    get keyExpr(): Function | string {
+    get keyExpr(): ((dependency: any) => any) | string {
         return this._getOption('keyExpr');
     }
-    set keyExpr(value: Function | string) {
+    set keyExpr(value: ((dependency: any) => any) | string) {
         this._setOption('keyExpr', value);
     }
 
     @Input()
-    get predecessorIdExpr(): Function | string {
+    get predecessorIdExpr(): ((dependency: any, value: any) => any) | string {
         return this._getOption('predecessorIdExpr');
     }
-    set predecessorIdExpr(value: Function | string) {
+    set predecessorIdExpr(value: ((dependency: any, value: any) => any) | string) {
         this._setOption('predecessorIdExpr', value);
     }
 
     @Input()
-    get successorIdExpr(): Function | string {
+    get successorIdExpr(): ((dependency: any, value: any) => any) | string {
         return this._getOption('successorIdExpr');
     }
-    set successorIdExpr(value: Function | string) {
+    set successorIdExpr(value: ((dependency: any, value: any) => any) | string) {
         this._setOption('successorIdExpr', value);
     }
 
     @Input()
-    get typeExpr(): Function | string {
+    get typeExpr(): ((dependency: any, value: any) => any) | string {
         return this._getOption('typeExpr');
     }
-    set typeExpr(value: Function | string) {
+    set typeExpr(value: ((dependency: any, value: any) => any) | string) {
         this._setOption('typeExpr', value);
     }
 
diff --git a/packages/devextreme-angular/src/ui/gantt/nested/resource-assignments.ts b/packages/devextreme-angular/src/ui/gantt/nested/resource-assignments.ts
index a8d010f062f7..ca8409a1b51b 100644
--- a/packages/devextreme-angular/src/ui/gantt/nested/resource-assignments.ts
+++ b/packages/devextreme-angular/src/ui/gantt/nested/resource-assignments.ts
@@ -41,26 +41,26 @@ export class DxoGanttResourceAssignmentsComponent extends NestedOption implement
     }
 
     @Input()
-    get keyExpr(): Function | string {
+    get keyExpr(): ((resourceAssignment: any) => any) | string {
         return this._getOption('keyExpr');
     }
-    set keyExpr(value: Function | string) {
+    set keyExpr(value: ((resourceAssignment: any) => any) | string) {
         this._setOption('keyExpr', value);
     }
 
     @Input()
-    get resourceIdExpr(): Function | string {
+    get resourceIdExpr(): ((resourceAssignment: any, value: any) => any) | string {
         return this._getOption('resourceIdExpr');
     }
-    set resourceIdExpr(value: Function | string) {
+    set resourceIdExpr(value: ((resourceAssignment: any, value: any) => any) | string) {
         this._setOption('resourceIdExpr', value);
     }
 
     @Input()
-    get taskIdExpr(): Function | string {
+    get taskIdExpr(): ((resourceAssignment: any, value: any) => any) | string {
         return this._getOption('taskIdExpr');
     }
-    set taskIdExpr(value: Function | string) {
+    set taskIdExpr(value: ((resourceAssignment: any, value: any) => any) | string) {
         this._setOption('taskIdExpr', value);
     }
 
diff --git a/packages/devextreme-angular/src/ui/gantt/nested/resources.ts b/packages/devextreme-angular/src/ui/gantt/nested/resources.ts
index a766c0bc2993..08e605118ab2 100644
--- a/packages/devextreme-angular/src/ui/gantt/nested/resources.ts
+++ b/packages/devextreme-angular/src/ui/gantt/nested/resources.ts
@@ -33,10 +33,10 @@ import { NestedOption } from 'devextreme-angular/core';
 })
 export class DxoGanttResourcesComponent extends NestedOption implements OnDestroy, OnInit  {
     @Input()
-    get colorExpr(): Function | string {
+    get colorExpr(): ((resource: any, value: any) => any) | string {
         return this._getOption('colorExpr');
     }
-    set colorExpr(value: Function | string) {
+    set colorExpr(value: ((resource: any, value: any) => any) | string) {
         this._setOption('colorExpr', value);
     }
 
@@ -49,18 +49,18 @@ export class DxoGanttResourcesComponent extends NestedOption implements OnDestro
     }
 
     @Input()
-    get keyExpr(): Function | string {
+    get keyExpr(): ((resource: any) => any) | string {
         return this._getOption('keyExpr');
     }
-    set keyExpr(value: Function | string) {
+    set keyExpr(value: ((resource: any) => any) | string) {
         this._setOption('keyExpr', value);
     }
 
     @Input()
-    get textExpr(): Function | string {
+    get textExpr(): ((resource: any, value: any) => string) | string {
         return this._getOption('textExpr');
     }
-    set textExpr(value: Function | string) {
+    set textExpr(value: ((resource: any, value: any) => string) | string) {
         this._setOption('textExpr', value);
     }
 
diff --git a/packages/devextreme-angular/src/ui/gantt/nested/tasks.ts b/packages/devextreme-angular/src/ui/gantt/nested/tasks.ts
index 5315e205eb66..b0b55af21e5a 100644
--- a/packages/devextreme-angular/src/ui/gantt/nested/tasks.ts
+++ b/packages/devextreme-angular/src/ui/gantt/nested/tasks.ts
@@ -33,10 +33,10 @@ import { NestedOption } from 'devextreme-angular/core';
 })
 export class DxoGanttTasksComponent extends NestedOption implements OnDestroy, OnInit  {
     @Input()
-    get colorExpr(): Function | string {
+    get colorExpr(): ((task: any, value: any) => any) | string {
         return this._getOption('colorExpr');
     }
-    set colorExpr(value: Function | string) {
+    set colorExpr(value: ((task: any, value: any) => any) | string) {
         this._setOption('colorExpr', value);
     }
 
@@ -49,50 +49,50 @@ export class DxoGanttTasksComponent extends NestedOption implements OnDestroy, O
     }
 
     @Input()
-    get endExpr(): Function | string {
+    get endExpr(): ((task: any, value: any) => any) | string {
         return this._getOption('endExpr');
     }
-    set endExpr(value: Function | string) {
+    set endExpr(value: ((task: any, value: any) => any) | string) {
         this._setOption('endExpr', value);
     }
 
     @Input()
-    get keyExpr(): Function | string {
+    get keyExpr(): ((task: any) => any) | string {
         return this._getOption('keyExpr');
     }
-    set keyExpr(value: Function | string) {
+    set keyExpr(value: ((task: any) => any) | string) {
         this._setOption('keyExpr', value);
     }
 
     @Input()
-    get parentIdExpr(): Function | string {
+    get parentIdExpr(): ((task: any, value: any) => any) | string {
         return this._getOption('parentIdExpr');
     }
-    set parentIdExpr(value: Function | string) {
+    set parentIdExpr(value: ((task: any, value: any) => any) | string) {
         this._setOption('parentIdExpr', value);
     }
 
     @Input()
-    get progressExpr(): Function | string {
+    get progressExpr(): ((task: any, value: any) => any) | string {
         return this._getOption('progressExpr');
     }
-    set progressExpr(value: Function | string) {
+    set progressExpr(value: ((task: any, value: any) => any) | string) {
         this._setOption('progressExpr', value);
     }
 
     @Input()
-    get startExpr(): Function | string {
+    get startExpr(): ((task: any, value: any) => any) | string {
         return this._getOption('startExpr');
     }
-    set startExpr(value: Function | string) {
+    set startExpr(value: ((task: any, value: any) => any) | string) {
         this._setOption('startExpr', value);
     }
 
     @Input()
-    get titleExpr(): Function | string {
+    get titleExpr(): ((task: any, value: any) => any) | string {
         return this._getOption('titleExpr');
     }
-    set titleExpr(value: Function | string) {
+    set titleExpr(value: ((task: any, value: any) => any) | string) {
         this._setOption('titleExpr', value);
     }
 
diff --git a/packages/devextreme-angular/src/ui/list/index.ts b/packages/devextreme-angular/src/ui/list/index.ts
index d9147805b0ed..be3347f5e4b4 100644
--- a/packages/devextreme-angular/src/ui/list/index.ts
+++ b/packages/devextreme-angular/src/ui/list/index.ts
@@ -379,10 +379,10 @@ export class DxListComponent<TItem = any, TKey = any> extends DxComponent implem
     
      */
     @Input()
-    get keyExpr(): Function | string {
+    get keyExpr(): ((item: any) => any) | string {
         return this._getOption('keyExpr');
     }
-    set keyExpr(value: Function | string) {
+    set keyExpr(value: ((item: any) => any) | string) {
         this._setOption('keyExpr', value);
     }
 
@@ -1119,7 +1119,7 @@ export class DxListComponent<TItem = any, TKey = any> extends DxComponent implem
      * This member supports the internal infrastructure and is not intended to be used directly from your code.
     
      */
-    @Output() keyExprChange: EventEmitter<Function | string>;
+    @Output() keyExprChange: EventEmitter<((item: any) => any) | string>;
 
     /**
     
diff --git a/packages/devextreme-angular/src/ui/menu/index.ts b/packages/devextreme-angular/src/ui/menu/index.ts
index 0b2ee236147c..f8cb504990d4 100644
--- a/packages/devextreme-angular/src/ui/menu/index.ts
+++ b/packages/devextreme-angular/src/ui/menu/index.ts
@@ -200,10 +200,10 @@ export class DxMenuComponent<TItem = any, TKey = any> extends DxComponent implem
     
      */
     @Input()
-    get disabledExpr(): Function | string {
+    get disabledExpr(): ((item: any) => boolean | undefined) | string {
         return this._getOption('disabledExpr');
     }
-    set disabledExpr(value: Function | string) {
+    set disabledExpr(value: ((item: any) => boolean | undefined) | string) {
         this._setOption('disabledExpr', value);
     }
 
@@ -317,10 +317,10 @@ export class DxMenuComponent<TItem = any, TKey = any> extends DxComponent implem
     
      */
     @Input()
-    get itemsExpr(): Function | string {
+    get itemsExpr(): ((item: any) => Array<any> | undefined) | string {
         return this._getOption('itemsExpr');
     }
-    set itemsExpr(value: Function | string) {
+    set itemsExpr(value: ((item: any) => Array<any> | undefined) | string) {
         this._setOption('itemsExpr', value);
     }
 
@@ -382,10 +382,10 @@ export class DxMenuComponent<TItem = any, TKey = any> extends DxComponent implem
     
      */
     @Input()
-    get selectedExpr(): Function | string {
+    get selectedExpr(): ((item: any, value: boolean | undefined) => boolean | undefined) | string {
         return this._getOption('selectedExpr');
     }
-    set selectedExpr(value: Function | string) {
+    set selectedExpr(value: ((item: any, value: boolean | undefined) => boolean | undefined) | string) {
         this._setOption('selectedExpr', value);
     }
 
@@ -643,7 +643,7 @@ export class DxMenuComponent<TItem = any, TKey = any> extends DxComponent implem
      * This member supports the internal infrastructure and is not intended to be used directly from your code.
     
      */
-    @Output() disabledExprChange: EventEmitter<Function | string>;
+    @Output() disabledExprChange: EventEmitter<((item: any) => boolean | undefined) | string>;
 
     /**
     
@@ -706,7 +706,7 @@ export class DxMenuComponent<TItem = any, TKey = any> extends DxComponent implem
      * This member supports the internal infrastructure and is not intended to be used directly from your code.
     
      */
-    @Output() itemsExprChange: EventEmitter<Function | string>;
+    @Output() itemsExprChange: EventEmitter<((item: any) => Array<any> | undefined) | string>;
 
     /**
     
@@ -741,7 +741,7 @@ export class DxMenuComponent<TItem = any, TKey = any> extends DxComponent implem
      * This member supports the internal infrastructure and is not intended to be used directly from your code.
     
      */
-    @Output() selectedExprChange: EventEmitter<Function | string>;
+    @Output() selectedExprChange: EventEmitter<((item: any, value: boolean | undefined) => boolean | undefined) | string>;
 
     /**
     
diff --git a/packages/devextreme-angular/src/ui/scheduler/nested/options.ts b/packages/devextreme-angular/src/ui/scheduler/nested/options.ts
index adbb1f966b04..84e1fbfc4653 100644
--- a/packages/devextreme-angular/src/ui/scheduler/nested/options.ts
+++ b/packages/devextreme-angular/src/ui/scheduler/nested/options.ts
@@ -127,10 +127,10 @@ export class DxoSchedulerOptionsComponent extends NestedOption implements OnDest
     }
 
     @Input()
-    get keyExpr(): Function | string {
+    get keyExpr(): ((item: any) => any) | string {
         return this._getOption('keyExpr');
     }
-    set keyExpr(value: Function | string) {
+    set keyExpr(value: ((item: any) => any) | string) {
         this._setOption('keyExpr', value);
     }
 
diff --git a/packages/devextreme-angular/src/ui/scheduler/nested/tab-panel-options.ts b/packages/devextreme-angular/src/ui/scheduler/nested/tab-panel-options.ts
index d6b9ed69d413..15da4a0a51cf 100644
--- a/packages/devextreme-angular/src/ui/scheduler/nested/tab-panel-options.ts
+++ b/packages/devextreme-angular/src/ui/scheduler/nested/tab-panel-options.ts
@@ -176,10 +176,10 @@ export class DxoSchedulerTabPanelOptionsComponent extends NestedOption implement
     }
 
     @Input()
-    get keyExpr(): Function | string {
+    get keyExpr(): ((item: any) => any) | string {
         return this._getOption('keyExpr');
     }
-    set keyExpr(value: Function | string) {
+    set keyExpr(value: ((item: any) => any) | string) {
         this._setOption('keyExpr', value);
     }
 
diff --git a/packages/devextreme-angular/src/ui/tab-panel/index.ts b/packages/devextreme-angular/src/ui/tab-panel/index.ts
index 3e58daabeed0..029969f1066c 100644
--- a/packages/devextreme-angular/src/ui/tab-panel/index.ts
+++ b/packages/devextreme-angular/src/ui/tab-panel/index.ts
@@ -288,10 +288,10 @@ export class DxTabPanelComponent<TItem = any, TKey = any> extends DxComponent im
     
      */
     @Input()
-    get keyExpr(): Function | string {
+    get keyExpr(): ((item: any) => any) | string {
         return this._getOption('keyExpr');
     }
-    set keyExpr(value: Function | string) {
+    set keyExpr(value: ((item: any) => any) | string) {
         this._setOption('keyExpr', value);
     }
 
@@ -711,7 +711,7 @@ export class DxTabPanelComponent<TItem = any, TKey = any> extends DxComponent im
      * This member supports the internal infrastructure and is not intended to be used directly from your code.
     
      */
-    @Output() keyExprChange: EventEmitter<Function | string>;
+    @Output() keyExprChange: EventEmitter<((item: any) => any) | string>;
 
     /**
     
diff --git a/packages/devextreme-angular/src/ui/tabs/index.ts b/packages/devextreme-angular/src/ui/tabs/index.ts
index ebb60071ab37..4d5a2a56ee57 100644
--- a/packages/devextreme-angular/src/ui/tabs/index.ts
+++ b/packages/devextreme-angular/src/ui/tabs/index.ts
@@ -236,10 +236,10 @@ export class DxTabsComponent<TItem = any, TKey = any> extends DxComponent implem
     
      */
     @Input()
-    get keyExpr(): Function | string {
+    get keyExpr(): ((item: any) => any) | string {
         return this._getOption('keyExpr');
     }
-    set keyExpr(value: Function | string) {
+    set keyExpr(value: ((item: any) => any) | string) {
         this._setOption('keyExpr', value);
     }
 
@@ -620,7 +620,7 @@ export class DxTabsComponent<TItem = any, TKey = any> extends DxComponent implem
      * This member supports the internal infrastructure and is not intended to be used directly from your code.
     
      */
-    @Output() keyExprChange: EventEmitter<Function | string>;
+    @Output() keyExprChange: EventEmitter<((item: any) => any) | string>;
 
     /**
     
diff --git a/packages/devextreme-angular/src/ui/tree-list/index.ts b/packages/devextreme-angular/src/ui/tree-list/index.ts
index 21b8807f5167..c54228ab1a3c 100644
--- a/packages/devextreme-angular/src/ui/tree-list/index.ts
+++ b/packages/devextreme-angular/src/ui/tree-list/index.ts
@@ -776,10 +776,10 @@ export class DxTreeListComponent<TRowData = any, TKey = any> extends DxComponent
     
      */
     @Input()
-    get hasItemsExpr(): Function | string {
+    get hasItemsExpr(): ((item: any, value: boolean | undefined) => boolean | undefined) | string {
         return this._getOption('hasItemsExpr');
     }
-    set hasItemsExpr(value: Function | string) {
+    set hasItemsExpr(value: ((item: any, value: boolean | undefined) => boolean | undefined) | string) {
         this._setOption('hasItemsExpr', value);
     }
 
@@ -854,10 +854,10 @@ export class DxTreeListComponent<TRowData = any, TKey = any> extends DxComponent
     
      */
     @Input()
-    get itemsExpr(): Function | string {
+    get itemsExpr(): ((item: any, value: undefined | Array<any>) => Array<any> | undefined) | string {
         return this._getOption('itemsExpr');
     }
-    set itemsExpr(value: Function | string) {
+    set itemsExpr(value: ((item: any, value: undefined | Array<any>) => Array<any> | undefined) | string) {
         this._setOption('itemsExpr', value);
     }
 
@@ -880,10 +880,10 @@ export class DxTreeListComponent<TRowData = any, TKey = any> extends DxComponent
     
      */
     @Input()
-    get keyExpr(): Function | string {
+    get keyExpr(): ((item: any, value: any) => any) | string {
         return this._getOption('keyExpr');
     }
-    set keyExpr(value: Function | string) {
+    set keyExpr(value: ((item: any, value: any) => any) | string) {
         this._setOption('keyExpr', value);
     }
 
@@ -945,10 +945,10 @@ export class DxTreeListComponent<TRowData = any, TKey = any> extends DxComponent
     
      */
     @Input()
-    get parentIdExpr(): Function | string {
+    get parentIdExpr(): ((item: any, value: any) => any | undefined) | string {
         return this._getOption('parentIdExpr');
     }
-    set parentIdExpr(value: Function | string) {
+    set parentIdExpr(value: ((item: any, value: any) => any | undefined) | string) {
         this._setOption('parentIdExpr', value);
     }
 
@@ -1871,7 +1871,7 @@ export class DxTreeListComponent<TRowData = any, TKey = any> extends DxComponent
      * This member supports the internal infrastructure and is not intended to be used directly from your code.
     
      */
-    @Output() hasItemsExprChange: EventEmitter<Function | string>;
+    @Output() hasItemsExprChange: EventEmitter<((item: any, value: boolean | undefined) => boolean | undefined) | string>;
 
     /**
     
@@ -1913,7 +1913,7 @@ export class DxTreeListComponent<TRowData = any, TKey = any> extends DxComponent
      * This member supports the internal infrastructure and is not intended to be used directly from your code.
     
      */
-    @Output() itemsExprChange: EventEmitter<Function | string>;
+    @Output() itemsExprChange: EventEmitter<((item: any, value: undefined | Array<any>) => Array<any> | undefined) | string>;
 
     /**
     
@@ -1927,7 +1927,7 @@ export class DxTreeListComponent<TRowData = any, TKey = any> extends DxComponent
      * This member supports the internal infrastructure and is not intended to be used directly from your code.
     
      */
-    @Output() keyExprChange: EventEmitter<Function | string>;
+    @Output() keyExprChange: EventEmitter<((item: any, value: any) => any) | string>;
 
     /**
     
@@ -1962,7 +1962,7 @@ export class DxTreeListComponent<TRowData = any, TKey = any> extends DxComponent
      * This member supports the internal infrastructure and is not intended to be used directly from your code.
     
      */
-    @Output() parentIdExprChange: EventEmitter<Function | string>;
+    @Output() parentIdExprChange: EventEmitter<((item: any, value: any) => any | undefined) | string>;
 
     /**
     
diff --git a/packages/devextreme-angular/src/ui/tree-list/nested/tab-panel-options.ts b/packages/devextreme-angular/src/ui/tree-list/nested/tab-panel-options.ts
index 33ee73c34714..8608365a8172 100644
--- a/packages/devextreme-angular/src/ui/tree-list/nested/tab-panel-options.ts
+++ b/packages/devextreme-angular/src/ui/tree-list/nested/tab-panel-options.ts
@@ -176,10 +176,10 @@ export class DxoTreeListTabPanelOptionsComponent extends NestedOption implements
     }
 
     @Input()
-    get keyExpr(): Function | string {
+    get keyExpr(): ((item: any) => any) | string {
         return this._getOption('keyExpr');
     }
-    set keyExpr(value: Function | string) {
+    set keyExpr(value: ((item: any) => any) | string) {
         this._setOption('keyExpr', value);
     }
 
diff --git a/packages/devextreme-angular/src/ui/tree-view/index.ts b/packages/devextreme-angular/src/ui/tree-view/index.ts
index 873566eea746..3efada823a0d 100644
--- a/packages/devextreme-angular/src/ui/tree-view/index.ts
+++ b/packages/devextreme-angular/src/ui/tree-view/index.ts
@@ -197,10 +197,10 @@ export class DxTreeViewComponent<TItem = any, TKey = any> extends DxComponent im
     
      */
     @Input()
-    get disabledExpr(): Function | string {
+    get disabledExpr(): ((item: any) => boolean | undefined) | string {
         return this._getOption('disabledExpr');
     }
-    set disabledExpr(value: Function | string) {
+    set disabledExpr(value: ((item: any) => boolean | undefined) | string) {
         this._setOption('disabledExpr', value);
     }
 
@@ -262,10 +262,10 @@ export class DxTreeViewComponent<TItem = any, TKey = any> extends DxComponent im
     
      */
     @Input()
-    get expandedExpr(): Function | string {
+    get expandedExpr(): ((item: any, value: boolean | undefined) => boolean | undefined) | string {
         return this._getOption('expandedExpr');
     }
-    set expandedExpr(value: Function | string) {
+    set expandedExpr(value: ((item: any, value: boolean | undefined) => boolean | undefined) | string) {
         this._setOption('expandedExpr', value);
     }
 
@@ -327,10 +327,10 @@ export class DxTreeViewComponent<TItem = any, TKey = any> extends DxComponent im
     
      */
     @Input()
-    get hasItemsExpr(): Function | string {
+    get hasItemsExpr(): ((item: any) => boolean | undefined) | string {
         return this._getOption('hasItemsExpr');
     }
-    set hasItemsExpr(value: Function | string) {
+    set hasItemsExpr(value: ((item: any) => boolean | undefined) | string) {
         this._setOption('hasItemsExpr', value);
     }
 
@@ -405,10 +405,10 @@ export class DxTreeViewComponent<TItem = any, TKey = any> extends DxComponent im
     
      */
     @Input()
-    get itemsExpr(): Function | string {
+    get itemsExpr(): ((item: any) => Array<any> | undefined) | string {
         return this._getOption('itemsExpr');
     }
-    set itemsExpr(value: Function | string) {
+    set itemsExpr(value: ((item: any) => Array<any> | undefined) | string) {
         this._setOption('itemsExpr', value);
     }
 
@@ -431,10 +431,10 @@ export class DxTreeViewComponent<TItem = any, TKey = any> extends DxComponent im
     
      */
     @Input()
-    get keyExpr(): Function | string {
+    get keyExpr(): ((item: any) => any) | string {
         return this._getOption('keyExpr');
     }
-    set keyExpr(value: Function | string) {
+    set keyExpr(value: ((item: any) => any) | string) {
         this._setOption('keyExpr', value);
     }
 
@@ -457,10 +457,10 @@ export class DxTreeViewComponent<TItem = any, TKey = any> extends DxComponent im
     
      */
     @Input()
-    get parentIdExpr(): Function | string {
+    get parentIdExpr(): ((item: any) => any | undefined) | string {
         return this._getOption('parentIdExpr');
     }
-    set parentIdExpr(value: Function | string) {
+    set parentIdExpr(value: ((item: any) => any | undefined) | string) {
         this._setOption('parentIdExpr', value);
     }
 
@@ -613,10 +613,10 @@ export class DxTreeViewComponent<TItem = any, TKey = any> extends DxComponent im
     
      */
     @Input()
-    get selectedExpr(): Function | string {
+    get selectedExpr(): ((item: any, value: boolean | undefined) => boolean | undefined) | string {
         return this._getOption('selectedExpr');
     }
-    set selectedExpr(value: Function | string) {
+    set selectedExpr(value: ((item: any, value: boolean | undefined) => boolean | undefined) | string) {
         this._setOption('selectedExpr', value);
     }
 
@@ -889,7 +889,7 @@ export class DxTreeViewComponent<TItem = any, TKey = any> extends DxComponent im
      * This member supports the internal infrastructure and is not intended to be used directly from your code.
     
      */
-    @Output() disabledExprChange: EventEmitter<Function | string>;
+    @Output() disabledExprChange: EventEmitter<((item: any) => boolean | undefined) | string>;
 
     /**
     
@@ -924,7 +924,7 @@ export class DxTreeViewComponent<TItem = any, TKey = any> extends DxComponent im
      * This member supports the internal infrastructure and is not intended to be used directly from your code.
     
      */
-    @Output() expandedExprChange: EventEmitter<Function | string>;
+    @Output() expandedExprChange: EventEmitter<((item: any, value: boolean | undefined) => boolean | undefined) | string>;
 
     /**
     
@@ -959,7 +959,7 @@ export class DxTreeViewComponent<TItem = any, TKey = any> extends DxComponent im
      * This member supports the internal infrastructure and is not intended to be used directly from your code.
     
      */
-    @Output() hasItemsExprChange: EventEmitter<Function | string>;
+    @Output() hasItemsExprChange: EventEmitter<((item: any) => boolean | undefined) | string>;
 
     /**
     
@@ -1001,7 +1001,7 @@ export class DxTreeViewComponent<TItem = any, TKey = any> extends DxComponent im
      * This member supports the internal infrastructure and is not intended to be used directly from your code.
     
      */
-    @Output() itemsExprChange: EventEmitter<Function | string>;
+    @Output() itemsExprChange: EventEmitter<((item: any) => Array<any> | undefined) | string>;
 
     /**
     
@@ -1015,7 +1015,7 @@ export class DxTreeViewComponent<TItem = any, TKey = any> extends DxComponent im
      * This member supports the internal infrastructure and is not intended to be used directly from your code.
     
      */
-    @Output() keyExprChange: EventEmitter<Function | string>;
+    @Output() keyExprChange: EventEmitter<((item: any) => any) | string>;
 
     /**
     
@@ -1029,7 +1029,7 @@ export class DxTreeViewComponent<TItem = any, TKey = any> extends DxComponent im
      * This member supports the internal infrastructure and is not intended to be used directly from your code.
     
      */
-    @Output() parentIdExprChange: EventEmitter<Function | string>;
+    @Output() parentIdExprChange: EventEmitter<((item: any) => any | undefined) | string>;
 
     /**
     
@@ -1113,7 +1113,7 @@ export class DxTreeViewComponent<TItem = any, TKey = any> extends DxComponent im
      * This member supports the internal infrastructure and is not intended to be used directly from your code.
     
      */
-    @Output() selectedExprChange: EventEmitter<Function | string>;
+    @Output() selectedExprChange: EventEmitter<((item: any, value: boolean | undefined) => boolean | undefined) | string>;
 
     /**
     
diff --git a/packages/devextreme-react/src/card-view.ts b/packages/devextreme-react/src/card-view.ts
index 3f34ceb24fca..47e8ad788ccf 100644
--- a/packages/devextreme-react/src/card-view.ts
+++ b/packages/devextreme-react/src/card-view.ts
@@ -2569,7 +2569,7 @@ type ITabPanelOptionsProps = React.PropsWithChildren<{
   items?: Array<any | dxTabPanelItem | string>;
   itemTemplate?: ((itemData: any, itemIndex: number, itemElement: any) => string | any) | template;
   itemTitleTemplate?: ((itemData: any, itemIndex: number, itemElement: any) => string | any) | template;
-  keyExpr?: (() => void) | string;
+  keyExpr?: ((item: any) => any) | string;
   loop?: boolean;
   noDataText?: string;
   onContentReady?: ((e: TabPanelContentReadyEvent) => void);
diff --git a/packages/devextreme-react/src/chat.ts b/packages/devextreme-react/src/chat.ts
index 34e74a4807fb..a342b008f619 100644
--- a/packages/devextreme-react/src/chat.ts
+++ b/packages/devextreme-react/src/chat.ts
@@ -528,7 +528,7 @@ type ISuggestionsProps = React.PropsWithChildren<{
   hint?: string | undefined;
   hoverStateEnabled?: boolean;
   items?: Array<dxButtonGroupItem>;
-  keyExpr?: (() => void) | string;
+  keyExpr?: ((item: any) => any) | string;
   onContentReady?: ((e: ButtonGroupContentReadyEvent) => void);
   onDisposing?: ((e: ButtonGroupDisposingEvent) => void);
   onInitialized?: ((e: ButtonGroupInitializedEvent) => void);
diff --git a/packages/devextreme-react/src/data-grid.ts b/packages/devextreme-react/src/data-grid.ts
index e5efdc3db829..46a42de97cc9 100644
--- a/packages/devextreme-react/src/data-grid.ts
+++ b/packages/devextreme-react/src/data-grid.ts
@@ -3601,7 +3601,7 @@ type ITabPanelOptionsProps = React.PropsWithChildren<{
   items?: Array<any | dxTabPanelItem | string>;
   itemTemplate?: ((itemData: any, itemIndex: number, itemElement: any) => string | any) | template;
   itemTitleTemplate?: ((itemData: any, itemIndex: number, itemElement: any) => string | any) | template;
-  keyExpr?: (() => void) | string;
+  keyExpr?: ((item: any) => any) | string;
   loop?: boolean;
   noDataText?: string;
   onContentReady?: ((e: TabPanelContentReadyEvent) => void);
diff --git a/packages/devextreme-react/src/form.ts b/packages/devextreme-react/src/form.ts
index 2630c3e67fce..054218d9e6c6 100644
--- a/packages/devextreme-react/src/form.ts
+++ b/packages/devextreme-react/src/form.ts
@@ -856,7 +856,7 @@ type ITabPanelOptionsProps = React.PropsWithChildren<{
   items?: Array<any | dxTabPanelItem | string>;
   itemTemplate?: ((itemData: any, itemIndex: number, itemElement: any) => string | any) | template;
   itemTitleTemplate?: ((itemData: any, itemIndex: number, itemElement: any) => string | any) | template;
-  keyExpr?: (() => void) | string;
+  keyExpr?: ((item: any) => any) | string;
   loop?: boolean;
   noDataText?: string;
   onContentReady?: ((e: TabPanelContentReadyEvent) => void);
diff --git a/packages/devextreme-react/src/gantt.ts b/packages/devextreme-react/src/gantt.ts
index bc15ed6dc93c..549e351d280c 100644
--- a/packages/devextreme-react/src/gantt.ts
+++ b/packages/devextreme-react/src/gantt.ts
@@ -388,10 +388,10 @@ const ContextMenuItemItem = Object.assign<typeof _componentContextMenuItemItem,
 // Gantt
 type IDependenciesProps = React.PropsWithChildren<{
   dataSource?: Array<any> | DataSource | DataSourceOptions | null | Store | string;
-  keyExpr?: (() => void) | string;
-  predecessorIdExpr?: (() => void) | string;
-  successorIdExpr?: (() => void) | string;
-  typeExpr?: (() => void) | string;
+  keyExpr?: ((dependency: any) => any) | string;
+  predecessorIdExpr?: ((dependency: any, value: any) => any) | string;
+  successorIdExpr?: ((dependency: any, value: any) => any) | string;
+  typeExpr?: ((dependency: any, value: any) => any) | string;
 }>
 const _componentDependencies = (props: IDependenciesProps) => {
   return React.createElement(NestedOption<IDependenciesProps>, {
@@ -656,9 +656,9 @@ const OperationDescriptions = Object.assign<typeof _componentOperationDescriptio
 // Gantt
 type IResourceAssignmentsProps = React.PropsWithChildren<{
   dataSource?: Array<any> | DataSource | DataSourceOptions | null | Store | string;
-  keyExpr?: (() => void) | string;
-  resourceIdExpr?: (() => void) | string;
-  taskIdExpr?: (() => void) | string;
+  keyExpr?: ((resourceAssignment: any) => any) | string;
+  resourceIdExpr?: ((resourceAssignment: any, value: any) => any) | string;
+  taskIdExpr?: ((resourceAssignment: any, value: any) => any) | string;
 }>
 const _componentResourceAssignments = (props: IResourceAssignmentsProps) => {
   return React.createElement(NestedOption<IResourceAssignmentsProps>, {
@@ -676,10 +676,10 @@ const ResourceAssignments = Object.assign<typeof _componentResourceAssignments,
 // owners:
 // Gantt
 type IResourcesProps = React.PropsWithChildren<{
-  colorExpr?: (() => void) | string;
+  colorExpr?: ((resource: any, value: any) => any) | string;
   dataSource?: Array<any> | DataSource | DataSourceOptions | null | Store | string;
-  keyExpr?: (() => void) | string;
-  textExpr?: (() => void) | string;
+  keyExpr?: ((resource: any) => any) | string;
+  textExpr?: ((resource: any, value: any) => string) | string;
 }>
 const _componentResources = (props: IResourcesProps) => {
   return React.createElement(NestedOption<IResourcesProps>, {
@@ -783,14 +783,14 @@ const StripLine = Object.assign<typeof _componentStripLine, NestedComponentMeta>
 // owners:
 // Gantt
 type ITasksProps = React.PropsWithChildren<{
-  colorExpr?: (() => void) | string;
+  colorExpr?: ((task: any, value: any) => any) | string;
   dataSource?: Array<any> | DataSource | DataSourceOptions | null | Store | string;
-  endExpr?: (() => void) | string;
-  keyExpr?: (() => void) | string;
-  parentIdExpr?: (() => void) | string;
-  progressExpr?: (() => void) | string;
-  startExpr?: (() => void) | string;
-  titleExpr?: (() => void) | string;
+  endExpr?: ((task: any, value: any) => any) | string;
+  keyExpr?: ((task: any) => any) | string;
+  parentIdExpr?: ((task: any, value: any) => any) | string;
+  progressExpr?: ((task: any, value: any) => any) | string;
+  startExpr?: ((task: any, value: any) => any) | string;
+  titleExpr?: ((task: any, value: any) => any) | string;
 }>
 const _componentTasks = (props: ITasksProps) => {
   return React.createElement(NestedOption<ITasksProps>, {
diff --git a/packages/devextreme-react/src/scheduler.ts b/packages/devextreme-react/src/scheduler.ts
index 1e62a2f2a4ff..47f1555713f9 100644
--- a/packages/devextreme-react/src/scheduler.ts
+++ b/packages/devextreme-react/src/scheduler.ts
@@ -809,7 +809,7 @@ type IOptionsProps = React.PropsWithChildren<{
   hint?: string | undefined;
   hoverStateEnabled?: boolean;
   items?: Array<dxButtonGroupItem | SchedulerPredefinedDateNavigatorItem>;
-  keyExpr?: (() => void) | string;
+  keyExpr?: ((item: any) => any) | string;
   onContentReady?: ((e: ButtonGroupContentReadyEvent) => void);
   onDisposing?: ((e: ButtonGroupDisposingEvent) => void);
   onInitialized?: ((e: ButtonGroupInitializedEvent) => void);
@@ -1223,7 +1223,7 @@ type ITabPanelOptionsProps = React.PropsWithChildren<{
   items?: Array<any | dxTabPanelItem | string>;
   itemTemplate?: ((itemData: any, itemIndex: number, itemElement: any) => string | any) | template;
   itemTitleTemplate?: ((itemData: any, itemIndex: number, itemElement: any) => string | any) | template;
-  keyExpr?: (() => void) | string;
+  keyExpr?: ((item: any) => any) | string;
   loop?: boolean;
   noDataText?: string;
   onContentReady?: ((e: TabPanelContentReadyEvent) => void);
diff --git a/packages/devextreme-react/src/tree-list.ts b/packages/devextreme-react/src/tree-list.ts
index a618090fdfff..df28875a4f52 100644
--- a/packages/devextreme-react/src/tree-list.ts
+++ b/packages/devextreme-react/src/tree-list.ts
@@ -3118,7 +3118,7 @@ type ITabPanelOptionsProps = React.PropsWithChildren<{
   items?: Array<any | dxTabPanelItem | string>;
   itemTemplate?: ((itemData: any, itemIndex: number, itemElement: any) => string | any) | template;
   itemTitleTemplate?: ((itemData: any, itemIndex: number, itemElement: any) => string | any) | template;
-  keyExpr?: (() => void) | string;
+  keyExpr?: ((item: any) => any) | string;
   loop?: boolean;
   noDataText?: string;
   onContentReady?: ((e: TabPanelContentReadyEvent) => void);
diff --git a/packages/devextreme-vue/src/accordion.ts b/packages/devextreme-vue/src/accordion.ts
index 558c466fd0c1..93f0c6d35f9a 100644
--- a/packages/devextreme-vue/src/accordion.ts
+++ b/packages/devextreme-vue/src/accordion.ts
@@ -88,7 +88,7 @@ const componentConfig = {
     items: Array as PropType<Array<any | dxAccordionItem | string>>,
     itemTemplate: {},
     itemTitleTemplate: {},
-    keyExpr: [Function, String] as PropType<((() => void)) | string>,
+    keyExpr: [Function, String] as PropType<(((item: any) => any)) | string>,
     multiple: Boolean,
     noDataText: String,
     onContentReady: Function as PropType<((e: ContentReadyEvent) => void)>,
diff --git a/packages/devextreme-vue/src/button-group.ts b/packages/devextreme-vue/src/button-group.ts
index 2a4e7aade611..0f300e8e3d16 100644
--- a/packages/devextreme-vue/src/button-group.ts
+++ b/packages/devextreme-vue/src/button-group.ts
@@ -62,7 +62,7 @@ const componentConfig = {
     hint: String,
     hoverStateEnabled: Boolean,
     items: Array as PropType<Array<dxButtonGroupItem>>,
-    keyExpr: [Function, String] as PropType<((() => void)) | string>,
+    keyExpr: [Function, String] as PropType<(((item: any) => any)) | string>,
     onContentReady: Function as PropType<((e: ContentReadyEvent) => void)>,
     onDisposing: Function as PropType<((e: DisposingEvent) => void)>,
     onInitialized: Function as PropType<((e: InitializedEvent) => void)>,
diff --git a/packages/devextreme-vue/src/card-view.ts b/packages/devextreme-vue/src/card-view.ts
index 83373a58575b..fc4c07d68fd9 100644
--- a/packages/devextreme-vue/src/card-view.ts
+++ b/packages/devextreme-vue/src/card-view.ts
@@ -3020,7 +3020,7 @@ const DxTabPanelOptionsConfig = {
     items: Array as PropType<Array<any | dxTabPanelItem | string>>,
     itemTemplate: {},
     itemTitleTemplate: {},
-    keyExpr: [Function, String] as PropType<((() => void)) | string>,
+    keyExpr: [Function, String] as PropType<(((item: any) => any)) | string>,
     loop: Boolean,
     noDataText: String,
     onContentReady: Function as PropType<((e: TabPanelContentReadyEvent) => void)>,
diff --git a/packages/devextreme-vue/src/chat.ts b/packages/devextreme-vue/src/chat.ts
index 5ce6628a93c6..53ac09dc0d0c 100644
--- a/packages/devextreme-vue/src/chat.ts
+++ b/packages/devextreme-vue/src/chat.ts
@@ -825,7 +825,7 @@ const DxSuggestionsConfig = {
     hint: String,
     hoverStateEnabled: Boolean,
     items: Array as PropType<Array<dxButtonGroupItem>>,
-    keyExpr: [Function, String] as PropType<((() => void)) | string>,
+    keyExpr: [Function, String] as PropType<(((item: any) => any)) | string>,
     onContentReady: Function as PropType<((e: ButtonGroupContentReadyEvent) => void)>,
     onDisposing: Function as PropType<((e: ButtonGroupDisposingEvent) => void)>,
     onInitialized: Function as PropType<((e: ButtonGroupInitializedEvent) => void)>,
diff --git a/packages/devextreme-vue/src/context-menu.ts b/packages/devextreme-vue/src/context-menu.ts
index 0f4731f030a5..710e286b64fc 100644
--- a/packages/devextreme-vue/src/context-menu.ts
+++ b/packages/devextreme-vue/src/context-menu.ts
@@ -106,7 +106,7 @@ const componentConfig = {
     cssClass: String,
     dataSource: [Array, Object, String] as PropType<Array<dxContextMenuItem> | DataSource | DataSourceOptions | null | Store | string | Record<string, any>>,
     disabled: Boolean,
-    disabledExpr: [Function, String] as PropType<((() => void)) | string>,
+    disabledExpr: [Function, String] as PropType<(((item: any) => boolean | undefined)) | string>,
     displayExpr: [Function, String] as PropType<(((item: any) => string)) | string>,
     elementAttr: Object as PropType<Record<string, any>>,
     focusStateEnabled: Boolean,
@@ -115,7 +115,7 @@ const componentConfig = {
     hint: String,
     hoverStateEnabled: Boolean,
     items: Array as PropType<Array<any | dxContextMenuItem>>,
-    itemsExpr: [Function, String] as PropType<((() => void)) | string>,
+    itemsExpr: [Function, String] as PropType<(((item: any) => Array<any> | undefined)) | string>,
     itemTemplate: {},
     onContentReady: Function as PropType<((e: ContentReadyEvent) => void)>,
     onDisposing: Function as PropType<((e: DisposingEvent) => void)>,
@@ -133,7 +133,7 @@ const componentConfig = {
     position: Object as PropType<PositionConfig | Record<string, any>>,
     rtlEnabled: Boolean,
     selectByClick: Boolean,
-    selectedExpr: [Function, String] as PropType<((() => void)) | string>,
+    selectedExpr: [Function, String] as PropType<(((item: any, value: boolean) => boolean | undefined)) | string>,
     selectedItem: {},
     selectionMode: String as PropType<SingleOrNone>,
     showEvent: [Object, String] as PropType<Record<string, any> | string>,
diff --git a/packages/devextreme-vue/src/data-grid.ts b/packages/devextreme-vue/src/data-grid.ts
index 3015cf797c17..fd9ebec46f9f 100644
--- a/packages/devextreme-vue/src/data-grid.ts
+++ b/packages/devextreme-vue/src/data-grid.ts
@@ -4322,7 +4322,7 @@ const DxTabPanelOptionsConfig = {
     items: Array as PropType<Array<any | dxTabPanelItem | string>>,
     itemTemplate: {},
     itemTitleTemplate: {},
-    keyExpr: [Function, String] as PropType<((() => void)) | string>,
+    keyExpr: [Function, String] as PropType<(((item: any) => any)) | string>,
     loop: Boolean,
     noDataText: String,
     onContentReady: Function as PropType<((e: TabPanelContentReadyEvent) => void)>,
diff --git a/packages/devextreme-vue/src/form.ts b/packages/devextreme-vue/src/form.ts
index ae0b8dd12c24..15fac496202b 100644
--- a/packages/devextreme-vue/src/form.ts
+++ b/packages/devextreme-vue/src/form.ts
@@ -1050,7 +1050,7 @@ const DxTabPanelOptionsConfig = {
     items: Array as PropType<Array<any | dxTabPanelItem | string>>,
     itemTemplate: {},
     itemTitleTemplate: {},
-    keyExpr: [Function, String] as PropType<((() => void)) | string>,
+    keyExpr: [Function, String] as PropType<(((item: any) => any)) | string>,
     loop: Boolean,
     noDataText: String,
     onContentReady: Function as PropType<((e: TabPanelContentReadyEvent) => void)>,
diff --git a/packages/devextreme-vue/src/gantt.ts b/packages/devextreme-vue/src/gantt.ts
index 1b8c150a57c5..ce0163779b4d 100644
--- a/packages/devextreme-vue/src/gantt.ts
+++ b/packages/devextreme-vue/src/gantt.ts
@@ -610,10 +610,10 @@ const DxDependenciesConfig = {
   },
   props: {
     dataSource: [Array, Object, String] as PropType<Array<any> | DataSource | DataSourceOptions | null | Store | string | Record<string, any>>,
-    keyExpr: [Function, String] as PropType<((() => void)) | string>,
-    predecessorIdExpr: [Function, String] as PropType<((() => void)) | string>,
-    successorIdExpr: [Function, String] as PropType<((() => void)) | string>,
-    typeExpr: [Function, String] as PropType<((() => void)) | string>
+    keyExpr: [Function, String] as PropType<(((dependency: any) => any)) | string>,
+    predecessorIdExpr: [Function, String] as PropType<(((dependency: any, value: any) => any)) | string>,
+    successorIdExpr: [Function, String] as PropType<(((dependency: any, value: any) => any)) | string>,
+    typeExpr: [Function, String] as PropType<(((dependency: any, value: any) => any)) | string>
   }
 };
 
@@ -924,9 +924,9 @@ const DxResourceAssignmentsConfig = {
   },
   props: {
     dataSource: [Array, Object, String] as PropType<Array<any> | DataSource | DataSourceOptions | null | Store | string | Record<string, any>>,
-    keyExpr: [Function, String] as PropType<((() => void)) | string>,
-    resourceIdExpr: [Function, String] as PropType<((() => void)) | string>,
-    taskIdExpr: [Function, String] as PropType<((() => void)) | string>
+    keyExpr: [Function, String] as PropType<(((resourceAssignment: any) => any)) | string>,
+    resourceIdExpr: [Function, String] as PropType<(((resourceAssignment: any, value: any) => any)) | string>,
+    taskIdExpr: [Function, String] as PropType<(((resourceAssignment: any, value: any) => any)) | string>
   }
 };
 
@@ -946,10 +946,10 @@ const DxResourcesConfig = {
     "update:textExpr": null,
   },
   props: {
-    colorExpr: [Function, String] as PropType<((() => void)) | string>,
+    colorExpr: [Function, String] as PropType<(((resource: any, value: any) => any)) | string>,
     dataSource: [Array, Object, String] as PropType<Array<any> | DataSource | DataSourceOptions | null | Store | string | Record<string, any>>,
-    keyExpr: [Function, String] as PropType<((() => void)) | string>,
-    textExpr: [Function, String] as PropType<((() => void)) | string>
+    keyExpr: [Function, String] as PropType<(((resource: any) => any)) | string>,
+    textExpr: [Function, String] as PropType<(((resource: any, value: any) => string)) | string>
   }
 };
 
@@ -1066,14 +1066,14 @@ const DxTasksConfig = {
     "update:titleExpr": null,
   },
   props: {
-    colorExpr: [Function, String] as PropType<((() => void)) | string>,
+    colorExpr: [Function, String] as PropType<(((task: any, value: any) => any)) | string>,
     dataSource: [Array, Object, String] as PropType<Array<any> | DataSource | DataSourceOptions | null | Store | string | Record<string, any>>,
-    endExpr: [Function, String] as PropType<((() => void)) | string>,
-    keyExpr: [Function, String] as PropType<((() => void)) | string>,
-    parentIdExpr: [Function, String] as PropType<((() => void)) | string>,
-    progressExpr: [Function, String] as PropType<((() => void)) | string>,
-    startExpr: [Function, String] as PropType<((() => void)) | string>,
-    titleExpr: [Function, String] as PropType<((() => void)) | string>
+    endExpr: [Function, String] as PropType<(((task: any, value: any) => any)) | string>,
+    keyExpr: [Function, String] as PropType<(((task: any) => any)) | string>,
+    parentIdExpr: [Function, String] as PropType<(((task: any, value: any) => any)) | string>,
+    progressExpr: [Function, String] as PropType<(((task: any, value: any) => any)) | string>,
+    startExpr: [Function, String] as PropType<(((task: any, value: any) => any)) | string>,
+    titleExpr: [Function, String] as PropType<(((task: any, value: any) => any)) | string>
   }
 };
 
diff --git a/packages/devextreme-vue/src/list.ts b/packages/devextreme-vue/src/list.ts
index 47113d5ea735..541cfb96745d 100644
--- a/packages/devextreme-vue/src/list.ts
+++ b/packages/devextreme-vue/src/list.ts
@@ -201,7 +201,7 @@ const componentConfig = {
     itemHoldTimeout: Number,
     items: Array as PropType<Array<any | dxListItem | string>>,
     itemTemplate: {},
-    keyExpr: [Function, String] as PropType<((() => void)) | string>,
+    keyExpr: [Function, String] as PropType<(((item: any) => any)) | string>,
     menuItems: Array as PropType<Array<Record<string, any>>>,
     menuMode: String as PropType<ListMenuMode>,
     nextButtonText: String,
diff --git a/packages/devextreme-vue/src/menu.ts b/packages/devextreme-vue/src/menu.ts
index 1a94d34e8ec0..55d672779926 100644
--- a/packages/devextreme-vue/src/menu.ts
+++ b/packages/devextreme-vue/src/menu.ts
@@ -103,7 +103,7 @@ const componentConfig = {
     cssClass: String,
     dataSource: [Array, Object, String] as PropType<Array<dxMenuItem> | DataSource | DataSourceOptions | null | Store | string | Record<string, any>>,
     disabled: Boolean,
-    disabledExpr: [Function, String] as PropType<((() => void)) | string>,
+    disabledExpr: [Function, String] as PropType<(((item: any) => boolean | undefined)) | string>,
     displayExpr: [Function, String] as PropType<(((item: any) => string)) | string>,
     elementAttr: Object as PropType<Record<string, any>>,
     focusStateEnabled: Boolean,
@@ -112,7 +112,7 @@ const componentConfig = {
     hint: String,
     hoverStateEnabled: Boolean,
     items: Array as PropType<Array<any | dxMenuItem>>,
-    itemsExpr: [Function, String] as PropType<((() => void)) | string>,
+    itemsExpr: [Function, String] as PropType<(((item: any) => Array<any> | undefined)) | string>,
     itemTemplate: {},
     onContentReady: Function as PropType<((e: ContentReadyEvent) => void)>,
     onDisposing: Function as PropType<((e: DisposingEvent) => void)>,
@@ -129,7 +129,7 @@ const componentConfig = {
     orientation: String as PropType<Orientation>,
     rtlEnabled: Boolean,
     selectByClick: Boolean,
-    selectedExpr: [Function, String] as PropType<((() => void)) | string>,
+    selectedExpr: [Function, String] as PropType<(((item: any, value: boolean) => boolean | undefined)) | string>,
     selectedItem: {},
     selectionMode: String as PropType<SingleOrNone>,
     showFirstSubmenuMode: [Object, String] as PropType<Record<string, any> | SubmenuShowMode>,
diff --git a/packages/devextreme-vue/src/scheduler.ts b/packages/devextreme-vue/src/scheduler.ts
index 7d468cb8c2b6..8f28c2098ac9 100644
--- a/packages/devextreme-vue/src/scheduler.ts
+++ b/packages/devextreme-vue/src/scheduler.ts
@@ -1135,7 +1135,7 @@ const DxOptionsConfig = {
     hint: String,
     hoverStateEnabled: Boolean,
     items: Array as PropType<Array<dxButtonGroupItem | SchedulerPredefinedDateNavigatorItem>>,
-    keyExpr: [Function, String] as PropType<((() => void)) | string>,
+    keyExpr: [Function, String] as PropType<(((item: any) => any)) | string>,
     onContentReady: Function as PropType<((e: ButtonGroupContentReadyEvent) => void)>,
     onDisposing: Function as PropType<((e: ButtonGroupDisposingEvent) => void)>,
     onInitialized: Function as PropType<((e: ButtonGroupInitializedEvent) => void)>,
@@ -1568,7 +1568,7 @@ const DxTabPanelOptionsConfig = {
     items: Array as PropType<Array<any | dxTabPanelItem | string>>,
     itemTemplate: {},
     itemTitleTemplate: {},
-    keyExpr: [Function, String] as PropType<((() => void)) | string>,
+    keyExpr: [Function, String] as PropType<(((item: any) => any)) | string>,
     loop: Boolean,
     noDataText: String,
     onContentReady: Function as PropType<((e: TabPanelContentReadyEvent) => void)>,
diff --git a/packages/devextreme-vue/src/tab-panel.ts b/packages/devextreme-vue/src/tab-panel.ts
index d9f4cdb1b144..ce5b3901dedb 100644
--- a/packages/devextreme-vue/src/tab-panel.ts
+++ b/packages/devextreme-vue/src/tab-panel.ts
@@ -103,7 +103,7 @@ const componentConfig = {
     items: Array as PropType<Array<any | dxTabPanelItem | string>>,
     itemTemplate: {},
     itemTitleTemplate: {},
-    keyExpr: [Function, String] as PropType<((() => void)) | string>,
+    keyExpr: [Function, String] as PropType<(((item: any) => any)) | string>,
     loop: Boolean,
     noDataText: String,
     onContentReady: Function as PropType<((e: ContentReadyEvent) => void)>,
diff --git a/packages/devextreme-vue/src/tabs.ts b/packages/devextreme-vue/src/tabs.ts
index 78bf15abb259..17e7999dbda8 100644
--- a/packages/devextreme-vue/src/tabs.ts
+++ b/packages/devextreme-vue/src/tabs.ts
@@ -91,7 +91,7 @@ const componentConfig = {
     itemHoldTimeout: Number,
     items: Array as PropType<Array<any | dxTabsItem | string>>,
     itemTemplate: {},
-    keyExpr: [Function, String] as PropType<((() => void)) | string>,
+    keyExpr: [Function, String] as PropType<(((item: any) => any)) | string>,
     noDataText: String,
     onContentReady: Function as PropType<((e: ContentReadyEvent) => void)>,
     onDisposing: Function as PropType<((e: DisposingEvent) => void)>,
diff --git a/packages/devextreme-vue/src/tree-list.ts b/packages/devextreme-vue/src/tree-list.ts
index 890d50a06aae..a5a7b51604a5 100644
--- a/packages/devextreme-vue/src/tree-list.ts
+++ b/packages/devextreme-vue/src/tree-list.ts
@@ -430,15 +430,15 @@ const componentConfig = {
     focusedRowEnabled: Boolean,
     focusedRowIndex: Number,
     focusedRowKey: {},
-    hasItemsExpr: [Function, String] as PropType<((() => void)) | string>,
+    hasItemsExpr: [Function, String] as PropType<(((item: any, value: boolean) => boolean | undefined)) | string>,
     headerFilter: Object as PropType<HeaderFilter | Record<string, any>>,
     height: [Number, String],
     highlightChanges: Boolean,
     hint: String,
     hoverStateEnabled: Boolean,
-    itemsExpr: [Function, String] as PropType<((() => void)) | string>,
+    itemsExpr: [Function, String] as PropType<(((item: any, value: Array<any>) => Array<any> | undefined)) | string>,
     keyboardNavigation: Object as PropType<Record<string, any>>,
-    keyExpr: [Function, String] as PropType<((() => void)) | string>,
+    keyExpr: [Function, String] as PropType<(((item: any, value: any) => any)) | string>,
     loadPanel: Object as PropType<Record<string, any>>,
     noDataText: String,
     onAdaptiveDetailRowPreparing: Function as PropType<((e: AdaptiveDetailRowPreparingEvent) => void)>,
@@ -485,7 +485,7 @@ const componentConfig = {
     onToolbarPreparing: Function as PropType<((e: ToolbarPreparingEvent) => void)>,
     pager: Object as PropType<Pager | Record<string, any> | PagerBase>,
     paging: Object as PropType<Record<string, any>>,
-    parentIdExpr: [Function, String] as PropType<((() => void)) | string>,
+    parentIdExpr: [Function, String] as PropType<(((item: any, value: any) => any | undefined)) | string>,
     remoteOperations: [String, Object] as PropType<Mode | Record<string, any>>,
     renderAsync: Boolean,
     repaintChangesOnly: Boolean,
@@ -3862,7 +3862,7 @@ const DxTabPanelOptionsConfig = {
     items: Array as PropType<Array<any | dxTabPanelItem | string>>,
     itemTemplate: {},
     itemTitleTemplate: {},
-    keyExpr: [Function, String] as PropType<((() => void)) | string>,
+    keyExpr: [Function, String] as PropType<(((item: any) => any)) | string>,
     loop: Boolean,
     noDataText: String,
     onContentReady: Function as PropType<((e: TabPanelContentReadyEvent) => void)>,
diff --git a/packages/devextreme-vue/src/tree-view.ts b/packages/devextreme-vue/src/tree-view.ts
index 24dbb49d8b32..3300c962b618 100644
--- a/packages/devextreme-vue/src/tree-view.ts
+++ b/packages/devextreme-vue/src/tree-view.ts
@@ -155,25 +155,25 @@ const componentConfig = {
     dataSource: [Array, Object, String] as PropType<Array<dxTreeViewItem> | DataSource | DataSourceOptions | null | Store | string | Record<string, any>>,
     dataStructure: String as PropType<DataStructure>,
     disabled: Boolean,
-    disabledExpr: [Function, String] as PropType<((() => void)) | string>,
+    disabledExpr: [Function, String] as PropType<(((item: any) => boolean | undefined)) | string>,
     disabledNodeSelectionMode: String as PropType<DisabledNodeSelectionMode>,
     displayExpr: [Function, String] as PropType<(((item: any) => string)) | string>,
     elementAttr: Object as PropType<Record<string, any>>,
     expandAllEnabled: Boolean,
-    expandedExpr: [Function, String] as PropType<((() => void)) | string>,
+    expandedExpr: [Function, String] as PropType<(((item: any, value: boolean) => boolean | undefined)) | string>,
     expandEvent: String as PropType<TreeViewExpandEvent>,
     expandIcon: String as PropType<null | string>,
     expandNodesRecursive: Boolean,
     focusStateEnabled: Boolean,
-    hasItemsExpr: [Function, String] as PropType<((() => void)) | string>,
+    hasItemsExpr: [Function, String] as PropType<(((item: any) => boolean | undefined)) | string>,
     height: [Number, String],
     hint: String,
     hoverStateEnabled: Boolean,
     itemHoldTimeout: Number,
     items: Array as PropType<Array<any | dxTreeViewItem>>,
-    itemsExpr: [Function, String] as PropType<((() => void)) | string>,
+    itemsExpr: [Function, String] as PropType<(((item: any) => Array<any> | undefined)) | string>,
     itemTemplate: {},
-    keyExpr: [Function, String] as PropType<((() => void)) | string>,
+    keyExpr: [Function, String] as PropType<(((item: any) => any)) | string>,
     noDataText: String,
     onContentReady: Function as PropType<((e: ContentReadyEvent) => void)>,
     onDisposing: Function as PropType<((e: DisposingEvent) => void)>,
@@ -188,7 +188,7 @@ const componentConfig = {
     onOptionChanged: Function as PropType<((e: OptionChangedEvent) => void)>,
     onSelectAllValueChanged: Function as PropType<((e: SelectAllValueChangedEvent) => void)>,
     onSelectionChanged: Function as PropType<((e: SelectionChangedEvent) => void)>,
-    parentIdExpr: [Function, String] as PropType<((() => void)) | string>,
+    parentIdExpr: [Function, String] as PropType<(((item: any) => any | undefined)) | string>,
     rootValue: {},
     rtlEnabled: Boolean,
     scrollDirection: String as PropType<ScrollDirection>,
@@ -200,7 +200,7 @@ const componentConfig = {
     searchValue: String,
     selectAllText: String,
     selectByClick: Boolean,
-    selectedExpr: [Function, String] as PropType<((() => void)) | string>,
+    selectedExpr: [Function, String] as PropType<(((item: any, value: boolean) => boolean | undefined)) | string>,
     selectionMode: String as PropType<SingleOrMultiple>,
     selectNodesRecursive: Boolean,
     showCheckBoxesMode: String as PropType<TreeViewCheckBoxMode>,
diff --git a/packages/devextreme/js/file_management/object_provider.d.ts b/packages/devextreme/js/file_management/object_provider.d.ts
index 9bb5db1c2738..578a6195c77f 100644
--- a/packages/devextreme/js/file_management/object_provider.d.ts
+++ b/packages/devextreme/js/file_management/object_provider.d.ts
@@ -15,7 +15,7 @@ export interface ObjectFileSystemProviderOptions extends FileSystemProviderBaseO
      * @docid
      * @public
      */
-    contentExpr?: string | Function;
+    contentExpr?: string | ((item: any, value?: any) => any);
     /**
      * @docid
      * @public
@@ -25,7 +25,7 @@ export interface ObjectFileSystemProviderOptions extends FileSystemProviderBaseO
      * @docid
      * @public
      */
-    itemsExpr?: string | Function;
+    itemsExpr?: string | ((item: any, value: any[] | undefined) => any[] | undefined);
 }
 /**
  * @docid
diff --git a/packages/devextreme/js/file_management/provider_base.d.ts b/packages/devextreme/js/file_management/provider_base.d.ts
index fe134b3d57b6..020630a54468 100644
--- a/packages/devextreme/js/file_management/provider_base.d.ts
+++ b/packages/devextreme/js/file_management/provider_base.d.ts
@@ -16,32 +16,32 @@ export interface FileSystemProviderBaseOptions<T = FileSystemProviderBase> {
      * @docid
      * @public
      */
-    dateModifiedExpr?: string | Function;
+    dateModifiedExpr?: string | ((item: any, value?: any) => any);
     /**
      * @docid
      * @public
      */
-    isDirectoryExpr?: string | Function;
+    isDirectoryExpr?: string | ((item: any, value?: any) => any);
     /**
      * @docid
      * @public
      */
-    keyExpr?: string | Function;
+    keyExpr?: string | ((item: any, value?: any) => any);
     /**
      * @docid
      * @public
      */
-    nameExpr?: string | Function;
+    nameExpr?: string | ((item: any, value?: any) => any);
     /**
      * @docid
      * @public
      */
-    sizeExpr?: string | Function;
+    sizeExpr?: string | ((item: any, value?: any) => any);
     /**
      * @docid
      * @public
      */
-    thumbnailExpr?: string | Function;
+    thumbnailExpr?: string | ((item: any, value?: any) => any);
 }
 /**
  * @docid
diff --git a/packages/devextreme/js/ui/button_group.d.ts b/packages/devextreme/js/ui/button_group.d.ts
index 55a3c572b33b..5c9833cc14df 100644
--- a/packages/devextreme/js/ui/button_group.d.ts
+++ b/packages/devextreme/js/ui/button_group.d.ts
@@ -118,7 +118,7 @@ export interface dxButtonGroupOptions extends WidgetOptions<dxButtonGroup> {
      * @default 'text'
      * @public
      */
-    keyExpr?: string | Function;
+    keyExpr?: string | ((item: any) => any);
     /**
      * @docid
      * @default null
diff --git a/packages/devextreme/js/ui/collection/ui.collection_widget.base.d.ts b/packages/devextreme/js/ui/collection/ui.collection_widget.base.d.ts
index d68c4b641fe5..ec12f01a27bc 100644
--- a/packages/devextreme/js/ui/collection/ui.collection_widget.base.d.ts
+++ b/packages/devextreme/js/ui/collection/ui.collection_widget.base.d.ts
@@ -80,7 +80,7 @@ export interface CollectionWidgetOptions<
      * @default null
      * @public
      */
-    keyExpr?: string | Function;
+    keyExpr?: string | ((item: TItem) => TKey);
     /**
      * @docid
      * @default "No data to display"
diff --git a/packages/devextreme/js/ui/gantt.d.ts b/packages/devextreme/js/ui/gantt.d.ts
index b9ca11ea65f2..a4a19036acf9 100644
--- a/packages/devextreme/js/ui/gantt.d.ts
+++ b/packages/devextreme/js/ui/gantt.d.ts
@@ -533,22 +533,22 @@ export interface dxGanttOptions extends WidgetOptions<dxGantt> {
        * @docid
        * @default "id"
        */
-      keyExpr?: string | Function;
+      keyExpr?: string | ((dependency: any) => any);
       /**
        * @docid
        * @default "predecessorId"
        */
-      predecessorIdExpr?: string | Function;
+      predecessorIdExpr?: string | ((dependency: any, value?: any) => any);
       /**
        * @docid
        * @default "successorId"
        */
-      successorIdExpr?: string | Function;
+      successorIdExpr?: string | ((dependency: any, value?: any) => any);
       /**
        * @docid
        * @default "type"
        */
-      typeExpr?: string | Function;
+      typeExpr?: string | ((dependency: any, value?: any) => any);
     };
     /**
      * @docid
@@ -875,17 +875,17 @@ export interface dxGanttOptions extends WidgetOptions<dxGantt> {
        * @docid
        * @default "id"
        */
-      keyExpr?: string | Function;
+      keyExpr?: string | ((resourceAssignment: any) => any);
       /**
        * @docid
        * @default "resourceId"
        */
-      resourceIdExpr?: string | Function;
+      resourceIdExpr?: string | ((resourceAssignment: any, value?: any) => any);
       /**
        * @docid
        * @default "taskId"
        */
-      taskIdExpr?: string | Function;
+      taskIdExpr?: string | ((resourceAssignment: any, value?: any) => any);
     };
     /**
      * @docid
@@ -897,7 +897,7 @@ export interface dxGanttOptions extends WidgetOptions<dxGantt> {
        * @docid
        * @default "color"
        */
-      colorExpr?: string | Function;
+      colorExpr?: string | ((resource: any, value?: any) => any);
       /**
        * @docid
        * @default null
@@ -908,12 +908,12 @@ export interface dxGanttOptions extends WidgetOptions<dxGantt> {
        * @docid
        * @default "id"
        */
-      keyExpr?: string | Function;
+      keyExpr?: string | ((resource: any) => any);
       /**
        * @docid
        * @default "text"
        */
-      textExpr?: string | Function;
+      textExpr?: string | ((resource: any, value?: any) => string);
     };
     /**
      * @docid
@@ -989,7 +989,7 @@ export interface dxGanttOptions extends WidgetOptions<dxGantt> {
        * @docid
        * @default "color"
        */
-      colorExpr?: string | Function;
+      colorExpr?: string | ((task: any, value?: any) => any);
       /**
        * @docid
        * @default null
@@ -1000,32 +1000,32 @@ export interface dxGanttOptions extends WidgetOptions<dxGantt> {
        * @docid
        * @default "end"
        */
-      endExpr?: string | Function;
+      endExpr?: string | ((task: any, value?: any) => any);
       /**
        * @docid
        * @default "id"
        */
-      keyExpr?: string | Function;
+      keyExpr?: string | ((task: any) => any);
       /**
        * @docid
        * @default "parentId"
        */
-      parentIdExpr?: string | Function;
+      parentIdExpr?: string | ((task: any, value?: any) => any);
       /**
        * @docid
        * @default "progress"
        */
-      progressExpr?: string | Function;
+      progressExpr?: string | ((task: any, value?: any) => any);
       /**
        * @docid
        * @default "start"
        */
-      startExpr?: string | Function;
+      startExpr?: string | ((task: any, value?: any) => any);
       /**
        * @docid
        * @default "title"
        */
-      titleExpr?: string | Function;
+      titleExpr?: string | ((task: any, value?: any) => any);
     };
     /**
      * @docid
diff --git a/packages/devextreme/js/ui/hierarchical_collection/ui.hierarchical_collection_widget.d.ts b/packages/devextreme/js/ui/hierarchical_collection/ui.hierarchical_collection_widget.d.ts
index 12057f38d358..78307e84de3c 100644
--- a/packages/devextreme/js/ui/hierarchical_collection/ui.hierarchical_collection_widget.d.ts
+++ b/packages/devextreme/js/ui/hierarchical_collection/ui.hierarchical_collection_widget.d.ts
@@ -19,7 +19,7 @@ export interface HierarchicalCollectionWidgetOptions<
      * @default 'disabled'
      * @public
      */
-    disabledExpr?: string | Function;
+    disabledExpr?: string | ((item: TItem) => boolean | undefined);
     /**
      * @docid
      * @default 'text'
@@ -44,19 +44,19 @@ export interface HierarchicalCollectionWidgetOptions<
      * @default 'items'
      * @public
      */
-    itemsExpr?: string | Function;
+    itemsExpr?: string | ((item: TItem) => TItem[] | undefined);
     /**
      * @docid
      * @default 'id'
      * @public
      */
-    keyExpr?: string | Function;
+    keyExpr?: string | ((item: TItem) => TKey);
     /**
      * @docid
      * @default 'selected'
      * @public
      */
-    selectedExpr?: string | Function;
+    selectedExpr?: string | ((item: TItem, value: boolean | undefined) => boolean | undefined);
 }
 /**
  * @docid
diff --git a/packages/devextreme/js/ui/tab_panel.d.ts b/packages/devextreme/js/ui/tab_panel.d.ts
index 89993ad74af5..da990eae6bb6 100644
--- a/packages/devextreme/js/ui/tab_panel.d.ts
+++ b/packages/devextreme/js/ui/tab_panel.d.ts
@@ -215,7 +215,7 @@ export interface dxTabPanelOptions<
      * @docid
      * @public
      */
-    keyExpr?: string | Function;
+    keyExpr?: string | ((item: TItem) => TKey);
     /**
      * @docid
      * @default null
diff --git a/packages/devextreme/js/ui/tree_list.d.ts b/packages/devextreme/js/ui/tree_list.d.ts
index 7eebdda84622..59711cffdc99 100644
--- a/packages/devextreme/js/ui/tree_list.d.ts
+++ b/packages/devextreme/js/ui/tree_list.d.ts
@@ -967,19 +967,19 @@ export type dxTreeListOptions<TRowData = any, TKey = any> = Omit<GridBaseOptions
      * @docid
      * @public
      */
-    hasItemsExpr?: string | Function;
+    hasItemsExpr?: string | ((item: TRowData, value: boolean | undefined) => boolean | undefined);
     /**
      * @docid
      * @default "items"
      * @public
      */
-    itemsExpr?: string | Function;
+    itemsExpr?: string | ((item: TRowData, value: undefined | TRowData[]) => TRowData[] | undefined);
     /**
      * @docid
      * @default "id"
      * @public
      */
-    keyExpr?: string | Function;
+    keyExpr?: string | ((item: TRowData, value?: TKey) => TKey);
     /**
      * @docid
      * @type_function_param1 e:{ui/tree_list:CellClickEvent}
@@ -1119,7 +1119,7 @@ export type dxTreeListOptions<TRowData = any, TKey = any> = Omit<GridBaseOptions
      * @default "parentId"
      * @public
      */
-    parentIdExpr?: string | Function;
+    parentIdExpr?: string | ((item: TRowData, value?: TKey) => TKey | undefined);
     /**
      * @docid
      * @default "auto"
diff --git a/packages/devextreme/js/ui/tree_view.d.ts b/packages/devextreme/js/ui/tree_view.d.ts
index 5bfda6255d2c..d83b61dce737 100644
--- a/packages/devextreme/js/ui/tree_view.d.ts
+++ b/packages/devextreme/js/ui/tree_view.d.ts
@@ -242,13 +242,13 @@ export interface dxTreeViewOptions<TItem extends ItemLike = any, TKey = any>
      * @hidden false
      * @public
      */
-    expandedExpr?: string | Function;
+    expandedExpr?: string | ((item: TItem, value: boolean | undefined) => boolean | undefined);
     /**
      * @docid
      * @default 'hasItems'
      * @public
      */
-    hasItemsExpr?: string | Function;
+    hasItemsExpr?: string | ((item: TItem) => boolean | undefined);
     /**
      * @docid
      * @type Array<dxTreeViewItem | any>
@@ -335,7 +335,7 @@ export interface dxTreeViewOptions<TItem extends ItemLike = any, TKey = any>
      * @hidden false
      * @public
      */
-    parentIdExpr?: string | Function;
+    parentIdExpr?: string | ((item: TItem) => TKey | undefined);
     /**
      * @docid
      * @default 0
diff --git a/packages/devextreme/ts/dx.all.d.ts b/packages/devextreme/ts/dx.all.d.ts
index 1c800528da72..baeb48cd2136 100644
--- a/packages/devextreme/ts/dx.all.d.ts
+++ b/packages/devextreme/ts/dx.all.d.ts
@@ -8506,27 +8506,27 @@ declare module DevExpress.fileManagement {
     /**
      * [descr:FileSystemProviderBaseOptions.dateModifiedExpr]
      */
-    dateModifiedExpr?: string | Function;
+    dateModifiedExpr?: string | ((item: any, value?: any) => any);
     /**
      * [descr:FileSystemProviderBaseOptions.isDirectoryExpr]
      */
-    isDirectoryExpr?: string | Function;
+    isDirectoryExpr?: string | ((item: any, value?: any) => any);
     /**
      * [descr:FileSystemProviderBaseOptions.keyExpr]
      */
-    keyExpr?: string | Function;
+    keyExpr?: string | ((item: any, value?: any) => any);
     /**
      * [descr:FileSystemProviderBaseOptions.nameExpr]
      */
-    nameExpr?: string | Function;
+    nameExpr?: string | ((item: any, value?: any) => any);
     /**
      * [descr:FileSystemProviderBaseOptions.sizeExpr]
      */
-    sizeExpr?: string | Function;
+    sizeExpr?: string | ((item: any, value?: any) => any);
     /**
      * [descr:FileSystemProviderBaseOptions.thumbnailExpr]
      */
-    thumbnailExpr?: string | Function;
+    thumbnailExpr?: string | ((item: any, value?: any) => any);
   }
   /**
    * [descr:ObjectFileSystemProvider]
@@ -8549,7 +8549,7 @@ declare module DevExpress.fileManagement {
     /**
      * [descr:ObjectFileSystemProviderOptions.contentExpr]
      */
-    contentExpr?: string | Function;
+    contentExpr?: string | ((item: any, value?: any) => any);
     /**
      * [descr:ObjectFileSystemProviderOptions.data]
      */
@@ -8557,7 +8557,9 @@ declare module DevExpress.fileManagement {
     /**
      * [descr:ObjectFileSystemProviderOptions.itemsExpr]
      */
-    itemsExpr?: string | Function;
+    itemsExpr?:
+      | string
+      | ((item: any, value: any[] | undefined) => any[] | undefined);
   }
   /**
    * [descr:RemoteFileSystemProvider]
@@ -8771,7 +8773,7 @@ declare module DevExpress.ui {
     /**
      * [descr:CollectionWidgetOptions.keyExpr]
      */
-    keyExpr?: string | Function;
+    keyExpr?: string | ((item: TItem) => TKey);
     /**
      * [descr:CollectionWidgetOptions.noDataText]
      */
@@ -9939,7 +9941,7 @@ declare module DevExpress.ui {
     /**
      * [descr:dxButtonGroupOptions.keyExpr]
      */
-    keyExpr?: string | Function;
+    keyExpr?: string | ((item: any) => any);
     /**
      * [descr:dxButtonGroupOptions.onItemClick]
      */
@@ -20663,19 +20665,19 @@ declare module DevExpress.ui {
       /**
        * [descr:dxGanttOptions.dependencies.keyExpr]
        */
-      keyExpr?: string | Function;
+      keyExpr?: string | ((dependency: any) => any);
       /**
        * [descr:dxGanttOptions.dependencies.predecessorIdExpr]
        */
-      predecessorIdExpr?: string | Function;
+      predecessorIdExpr?: string | ((dependency: any, value?: any) => any);
       /**
        * [descr:dxGanttOptions.dependencies.successorIdExpr]
        */
-      successorIdExpr?: string | Function;
+      successorIdExpr?: string | ((dependency: any, value?: any) => any);
       /**
        * [descr:dxGanttOptions.dependencies.typeExpr]
        */
-      typeExpr?: string | Function;
+      typeExpr?: string | ((dependency: any, value?: any) => any);
     };
     /**
      * [descr:dxGanttOptions.editing]
@@ -20903,15 +20905,15 @@ declare module DevExpress.ui {
       /**
        * [descr:dxGanttOptions.resourceAssignments.keyExpr]
        */
-      keyExpr?: string | Function;
+      keyExpr?: string | ((resourceAssignment: any) => any);
       /**
        * [descr:dxGanttOptions.resourceAssignments.resourceIdExpr]
        */
-      resourceIdExpr?: string | Function;
+      resourceIdExpr?: string | ((resourceAssignment: any, value?: any) => any);
       /**
        * [descr:dxGanttOptions.resourceAssignments.taskIdExpr]
        */
-      taskIdExpr?: string | Function;
+      taskIdExpr?: string | ((resourceAssignment: any, value?: any) => any);
     };
     /**
      * [descr:dxGanttOptions.resources]
@@ -20920,7 +20922,7 @@ declare module DevExpress.ui {
       /**
        * [descr:dxGanttOptions.resources.colorExpr]
        */
-      colorExpr?: string | Function;
+      colorExpr?: string | ((resource: any, value?: any) => any);
       /**
        * [descr:dxGanttOptions.resources.dataSource]
        */
@@ -20928,11 +20930,11 @@ declare module DevExpress.ui {
       /**
        * [descr:dxGanttOptions.resources.keyExpr]
        */
-      keyExpr?: string | Function;
+      keyExpr?: string | ((resource: any) => any);
       /**
        * [descr:dxGanttOptions.resources.textExpr]
        */
-      textExpr?: string | Function;
+      textExpr?: string | ((resource: any, value?: any) => string);
     };
     /**
      * [descr:dxGanttOptions.scaleType]
@@ -20986,7 +20988,7 @@ declare module DevExpress.ui {
       /**
        * [descr:dxGanttOptions.tasks.colorExpr]
        */
-      colorExpr?: string | Function;
+      colorExpr?: string | ((task: any, value?: any) => any);
       /**
        * [descr:dxGanttOptions.tasks.dataSource]
        */
@@ -20994,27 +20996,27 @@ declare module DevExpress.ui {
       /**
        * [descr:dxGanttOptions.tasks.endExpr]
        */
-      endExpr?: string | Function;
+      endExpr?: string | ((task: any, value?: any) => any);
       /**
        * [descr:dxGanttOptions.tasks.keyExpr]
        */
-      keyExpr?: string | Function;
+      keyExpr?: string | ((task: any) => any);
       /**
        * [descr:dxGanttOptions.tasks.parentIdExpr]
        */
-      parentIdExpr?: string | Function;
+      parentIdExpr?: string | ((task: any, value?: any) => any);
       /**
        * [descr:dxGanttOptions.tasks.progressExpr]
        */
-      progressExpr?: string | Function;
+      progressExpr?: string | ((task: any, value?: any) => any);
       /**
        * [descr:dxGanttOptions.tasks.startExpr]
        */
-      startExpr?: string | Function;
+      startExpr?: string | ((task: any, value?: any) => any);
       /**
        * [descr:dxGanttOptions.tasks.titleExpr]
        */
-      titleExpr?: string | Function;
+      titleExpr?: string | ((task: any, value?: any) => any);
     };
     /**
      * [descr:dxGanttOptions.toolbar]
@@ -28969,7 +28971,7 @@ declare module DevExpress.ui {
     /**
      * [descr:dxTabPanelOptions.keyExpr]
      */
-    keyExpr?: string | Function;
+    keyExpr?: string | ((item: TItem) => TKey);
     /**
      * [descr:dxTabPanelOptions.onTitleClick]
      */
@@ -32055,15 +32057,22 @@ declare module DevExpress.ui {
     /**
      * [descr:dxTreeListOptions.hasItemsExpr]
      */
-    hasItemsExpr?: string | Function;
+    hasItemsExpr?:
+      | string
+      | ((item: TRowData, value: boolean | undefined) => boolean | undefined);
     /**
      * [descr:dxTreeListOptions.itemsExpr]
      */
-    itemsExpr?: string | Function;
+    itemsExpr?:
+      | string
+      | ((
+          item: TRowData,
+          value: undefined | TRowData[]
+        ) => TRowData[] | undefined);
     /**
      * [descr:dxTreeListOptions.keyExpr]
      */
-    keyExpr?: string | Function;
+    keyExpr?: string | ((item: TRowData, value?: TKey) => TKey);
     /**
      * [descr:dxTreeListOptions.onCellClick]
      */
@@ -32167,7 +32176,9 @@ declare module DevExpress.ui {
     /**
      * [descr:dxTreeListOptions.parentIdExpr]
      */
-    parentIdExpr?: string | Function;
+    parentIdExpr?:
+      | string
+      | ((item: TRowData, value?: TKey) => TKey | undefined);
     /**
      * [descr:dxTreeListOptions.remoteOperations]
      */
@@ -32645,11 +32656,13 @@ declare module DevExpress.ui {
     /**
      * [descr:dxTreeViewOptions.expandedExpr]
      */
-    expandedExpr?: string | Function;
+    expandedExpr?:
+      | string
+      | ((item: TItem, value: boolean | undefined) => boolean | undefined);
     /**
      * [descr:dxTreeViewOptions.hasItemsExpr]
      */
-    hasItemsExpr?: string | Function;
+    hasItemsExpr?: string | ((item: TItem) => boolean | undefined);
     /**
      * [descr:dxTreeViewOptions.items]
      */
@@ -32711,7 +32724,7 @@ declare module DevExpress.ui {
     /**
      * [descr:dxTreeViewOptions.parentIdExpr]
      */
-    parentIdExpr?: string | Function;
+    parentIdExpr?: string | ((item: TItem) => TKey | undefined);
     /**
      * [descr:dxTreeViewOptions.rootValue]
      */
@@ -33272,7 +33285,7 @@ declare module DevExpress.ui {
     /**
      * [descr:HierarchicalCollectionWidgetOptions.disabledExpr]
      */
-    disabledExpr?: string | Function;
+    disabledExpr?: string | ((item: TItem) => boolean | undefined);
     /**
      * [descr:HierarchicalCollectionWidgetOptions.displayExpr]
      */
@@ -33288,15 +33301,17 @@ declare module DevExpress.ui {
     /**
      * [descr:HierarchicalCollectionWidgetOptions.itemsExpr]
      */
-    itemsExpr?: string | Function;
+    itemsExpr?: string | ((item: TItem) => TItem[] | undefined);
     /**
      * [descr:HierarchicalCollectionWidgetOptions.keyExpr]
      */
-    keyExpr?: string | Function;
+    keyExpr?: string | ((item: TItem) => TKey);
     /**
      * [descr:HierarchicalCollectionWidgetOptions.selectedExpr]
      */
-    selectedExpr?: string | Function;
+    selectedExpr?:
+      | string
+      | ((item: TItem, value: boolean | undefined) => boolean | undefined);
   }
   /**
    * [descr:MapLocation]