#3884 Expression language support for conditional sequence flow and conditional events (#3889)

* #3884 Expression language support for conditional sequence flow and conditional events

* #3884: Use ScriptCondition instead of ScriptEngineExpression

* #3884: Move logic to ConditionUtil and leave ScriptCondition unchanged

* #3884: Rename sequenceFlowId to elementId. Revert whitespace-only changes.

* #3884: Pass the id of the event definition instead of the activity

Author: rasmusfaber

modules/flowable-bpmn-converter/src/main/java/org/flowable/bpmn/converter/BaseBpmnXMLConverter.java

@@ -597,6 +597,10 @@ protected void writeConditionalDefinition(Event parentEvent, ConditionalEventDef
 
         if (StringUtils.isNotEmpty(conditionalDefinition.getConditionExpression())) {
             xtw.writeStartElement(ELEMENT_CONDITION);
+            if (conditionalDefinition.getConditionLanguage() != null) {
+                xtw.writeAttribute(XSI_PREFIX, XSI_NAMESPACE, "type", "tFormalExpression");
+                BpmnXMLUtil.writeDefaultAttribute(BpmnXMLConstants.ATTRIBUTE_SCRIPT_LANGUAGE, conditionalDefinition.getConditionLanguage(), xtw);
+            }
             xtw.writeCharacters(conditionalDefinition.getConditionExpression());
             xtw.writeEndElement();
         }

modules/flowable-bpmn-converter/src/main/java/org/flowable/bpmn/converter/SequenceFlowXMLConverter.java

@@ -16,6 +16,7 @@
 import javax.xml.stream.XMLStreamWriter;
 
 import org.apache.commons.lang3.StringUtils;
+import org.flowable.bpmn.constants.BpmnXMLConstants;
 import org.flowable.bpmn.converter.util.BpmnXMLUtil;
 import org.flowable.bpmn.model.BaseElement;
 import org.flowable.bpmn.model.BpmnModel;
@@ -66,6 +67,9 @@ protected void writeAdditionalChildElements(BaseElement element, BpmnModel model
         if (StringUtils.isNotEmpty(sequenceFlow.getConditionExpression())) {
             xtw.writeStartElement(ELEMENT_FLOW_CONDITION);
             xtw.writeAttribute(XSI_PREFIX, XSI_NAMESPACE, "type", "tFormalExpression");
+            if (sequenceFlow.getConditionLanguage() != null) {
+                BpmnXMLUtil.writeDefaultAttribute(BpmnXMLConstants.ATTRIBUTE_SCRIPT_LANGUAGE, sequenceFlow.getConditionLanguage(), xtw);
+            }
             xtw.writeCData(sequenceFlow.getConditionExpression());
             xtw.writeEndElement();
         }

modules/flowable-bpmn-converter/src/main/java/org/flowable/bpmn/converter/child/ConditionExpressionParser.java

@@ -30,10 +30,11 @@ public String getElementName() {
 
     @Override
     public void parseChildElement(XMLStreamReader xtr, BaseElement parentElement, BpmnModel model) throws Exception {
-        if (!(parentElement instanceof SequenceFlow)) {
+        if (!(parentElement instanceof SequenceFlow sequenceFlow)) {
             return;
         }
 
-        ((SequenceFlow) parentElement).setConditionExpression(xtr.getElementText().trim());
+        sequenceFlow.setConditionLanguage(xtr.getAttributeValue(null, ATTRIBUTE_SCRIPT_LANGUAGE));
+        sequenceFlow.setConditionExpression(xtr.getElementText().trim());
     }
 }

modules/flowable-bpmn-converter/src/main/java/org/flowable/bpmn/converter/child/ConditionParser.java

@@ -30,11 +30,12 @@ public String getElementName() {
 
     @Override
     public void parseChildElement(XMLStreamReader xtr, BaseElement parentElement, BpmnModel model) throws Exception {
-        if (!(parentElement instanceof ConditionalEventDefinition)) {
+        if (!(parentElement instanceof ConditionalEventDefinition conditionalEventDefinition)) {
             return;
         }
 
-        ((ConditionalEventDefinition) parentElement).setConditionExpression(xtr.getElementText().trim());
+        conditionalEventDefinition.setConditionLanguage(xtr.getAttributeValue(null, ATTRIBUTE_SCRIPT_LANGUAGE));
+        conditionalEventDefinition.setConditionExpression(xtr.getElementText().trim());
     }
 
     @Override

modules/flowable-bpmn-model/src/main/java/org/flowable/bpmn/model/ConditionalEventDefinition.java

@@ -18,6 +18,7 @@
 public class ConditionalEventDefinition extends EventDefinition {
 
     protected String conditionExpression;
+    protected String conditionLanguage;
 
     public String getConditionExpression() {
         return conditionExpression;
@@ -27,6 +28,14 @@ public void setConditionExpression(String conditionExpression) {
         this.conditionExpression = conditionExpression;
     }
 
+    public String getConditionLanguage() {
+        return conditionLanguage;
+    }
+
+    public void setConditionLanguage(String conditionLanguage) {
+        this.conditionLanguage = conditionLanguage;
+    }
+
     @Override
     public ConditionalEventDefinition clone() {
         ConditionalEventDefinition clone = new ConditionalEventDefinition();
@@ -37,5 +46,6 @@ public ConditionalEventDefinition clone() {
     public void setValues(ConditionalEventDefinition otherDefinition) {
         super.setValues(otherDefinition);
         setConditionExpression(otherDefinition.getConditionExpression());
+        setConditionLanguage(otherDefinition.getConditionLanguage());
     }
 }

modules/flowable-bpmn-model/src/main/java/org/flowable/bpmn/model/SequenceFlow.java

@@ -24,6 +24,7 @@
 public class SequenceFlow extends FlowElement {
 
     protected String conditionExpression;
+    protected String conditionLanguage;
     protected String sourceRef;
     protected String targetRef;
     protected String skipExpression;
@@ -60,6 +61,14 @@ public void setConditionExpression(String conditionExpression) {
         this.conditionExpression = conditionExpression;
     }
 
+    public String getConditionLanguage() {
+        return conditionLanguage;
+    }
+
+    public void setConditionLanguage(String conditionLanguage) {
+        this.conditionLanguage = conditionLanguage;
+    }
+
     public String getSourceRef() {
         return sourceRef;
     }
@@ -123,6 +132,7 @@ public SequenceFlow clone() {
     public void setValues(SequenceFlow otherFlow) {
         super.setValues(otherFlow);
         setConditionExpression(otherFlow.getConditionExpression());
+        setConditionLanguage(otherFlow.getConditionLanguage());
         setSourceRef(otherFlow.getSourceRef());
         setTargetRef(otherFlow.getTargetRef());
         setSkipExpression(otherFlow.getSkipExpression());

modules/flowable-engine/src/main/java/org/flowable/engine/delegate/event/FlowableConditionalEvent.java

@@ -24,4 +24,8 @@ public interface FlowableConditionalEvent extends FlowableActivityEvent {
      */
     String getConditionExpression();
 
+    /**
+     * @return the scripting language of the condition expression.
+     */
+    String getConditionLanguage();
 }

modules/flowable-engine/src/main/java/org/flowable/engine/delegate/event/impl/FlowableConditionalEventImpl.java

@@ -21,6 +21,7 @@
 public class FlowableConditionalEventImpl extends FlowableActivityEventImpl implements FlowableConditionalEvent {
 
     protected String conditionExpression;
+    protected String conditionLanguage;
 
     public FlowableConditionalEventImpl(FlowableEngineEventType type) {
         super(type);
@@ -34,4 +35,12 @@ public String getConditionExpression() {
     public void setConditionExpression(String conditionExpression) {
         this.conditionExpression = conditionExpression;
     }
+
+    public String getConditionLanguage() {
+        return conditionLanguage;
+    }
+
+    public void setConditionLanguage(String conditionLanguage) {
+        this.conditionLanguage = conditionLanguage;
+    }
 }

modules/flowable-engine/src/main/java/org/flowable/engine/delegate/event/impl/FlowableEventBuilder.java

@@ -368,7 +368,7 @@ public static FlowableMessageEvent createMessageEvent(FlowableEngineEventType ty
         return newEvent;
     }
 
-    public static FlowableConditionalEvent createConditionalEvent(FlowableEngineEventType type, String activityId, String conditionExpression,
+    public static FlowableConditionalEvent createConditionalEvent(FlowableEngineEventType type, String activityId, String conditionExpression, String conditionLanguage,
                     String executionId, String processInstanceId, String processDefinitionId) {
 
         FlowableConditionalEventImpl newEvent = new FlowableConditionalEventImpl(type);
@@ -377,6 +377,7 @@ public static FlowableConditionalEvent createConditionalEvent(FlowableEngineEven
         newEvent.setProcessDefinitionId(processDefinitionId);
         newEvent.setProcessInstanceId(processInstanceId);
         newEvent.setConditionExpression(conditionExpression);
+        newEvent.setConditionLanguage(conditionLanguage);
         return newEvent;
     }
 

modules/flowable-engine/src/main/java/org/flowable/engine/impl/Condition.java

@@ -22,5 +22,5 @@
  */
 public interface Condition extends Serializable {
 
-    boolean evaluate(String sequenceFlowId, DelegateExecution execution);
+    boolean evaluate(String elementId, DelegateExecution execution);
 }