feat: Variable assign supports set to null (#4965)

* feat: `Variable assign` supports set to `null`

Author: wangliang181230

apps/application/flow/step_node/variable_assign_node/impl/base_variable_assign_node.py

@@ -60,33 +60,44 @@ def handle(self, variable, evaluation):
                 val = variable['value']
                 evaluation(variable, val)
                 result['output_value'] = val
-        else:
+        elif variable['source'] == 'referencing':
             reference = self.get_reference_content(variable['reference'])
             evaluation(variable, reference)
             result['output_value'] = reference
+        else:
+            val = None
+            evaluation(variable, val)
+            result['output_value'] = val
+
+        # 获取输入输出值的类型，用于显示在执行详情页面中
+        result['input_type'] = type(result.get('input_value')).__name__ if result.get('input_value') is not None else 'null'
+        result['output_type'] = type(result.get('output_value')).__name__ if result.get('output_value') is not None else 'null'
+
         return result
 
     def execute(self, variable_list, **kwargs) -> NodeResult:
-        #
         result_list = []
-        is_chat = False
+        contains_chat_variable = False
         for variable in variable_list:
-            if 'fields' not in variable:
+            if not variable.get('fields'):
                 continue
-            if 'global' == variable['fields'][0]:
+
+            field0 = variable['fields'][0]
+            if 'global' == field0:
                 result = self.handle(variable, self.global_evaluation)
                 result_list.append(result)
-            if 'chat' == variable['fields'][0]:
+            elif 'chat' == field0:
                 result = self.handle(variable, self.chat_evaluation)
                 result_list.append(result)
-                is_chat = True
-            if 'loop' == variable['fields'][0]:
+                contains_chat_variable = True
+            elif 'loop' == field0:
                 result = self.handle(variable, self.loop_evaluation)
                 result_list.append(result)
-            if 'output' == variable['fields'][0]:
+            elif 'output' == field0:
                 result = self.handle(variable, self.out_evaluation)
                 result_list.append(result)
-        if is_chat:
+
+        if contains_chat_variable:
             from application.flow.loop_workflow_manage import LoopWorkflowManage
             if isinstance(self.workflow_manage, LoopWorkflowManage):
                 self.workflow_manage.parentWorkflowManage.get_chat_info().set_chat_variable(

ui/src/components/execution-detail-card/index.vue

@@ -882,7 +882,7 @@
               </h5>
               <div class="p-8-12 border-t-dashed lighter">
                 <div v-for="(f, i) in data.result_list" :key="i" class="mb-8">
-                  <span class="color-secondary">{{ f.name }}:</span> {{ f.input_value }}
+                  <span class="color-secondary">{{ f.name }} ({{ f.input_type }}):</span> {{ f.input_value }}
                 </div>
               </div>
             </div>
@@ -892,7 +892,7 @@
               </h5>
               <div class="p-8-12 border-t-dashed lighter">
                 <div v-for="(f, i) in data.result_list" :key="i" class="mb-8">
-                  <span class="color-secondary">{{ f.name }}:</span> {{ f.output_value }}
+                  <span class="color-secondary">{{ f.name }} ({{ f.output_type }}):</span> {{ f.output_value }}
                 </div>
               </div>
             </div>

ui/src/workflow/nodes/variable-assign-node/index.vue

@@ -45,6 +45,7 @@
             <el-select :teleported="false" v-model="item.source" size="small" style="width: 85px">
               <el-option :label="$t('workflow.variable.Referencing')" value="referencing" />
               <el-option :label="$t('common.custom')" value="custom" />
+              <el-option label="null" value="null" />
             </el-select>
           </div>
 
@@ -142,7 +143,7 @@
               </el-select>
             </el-form-item>
           </div>
-          <el-form-item v-else>
+          <el-form-item v-else-if="item.source === 'referencing'">
             <NodeCascader
               ref="nodeCascaderRef2"
               :nodeModel="nodeModel"