added expression resolver for activity name

modules/flowable-cmmn-engine/src/main/java/org/flowable/cmmn/engine/impl/behavior/impl/StageActivityBehavior.java

@@ -41,7 +41,10 @@ public StageActivityBehavior(Stage stage) {
     public void execute(CommandContext commandContext, PlanItemInstanceEntity planItemInstanceEntity) {
         if (planItemInstanceEntity.getName() == null && planItemInstanceEntity.getPlanItem().getName() != null) {
             Expression nameExpression = CommandContextUtil.getExpressionManager(commandContext).createExpression(planItemInstanceEntity.getPlanItem().getName());
-            planItemInstanceEntity.setName(nameExpression.getValue(planItemInstanceEntity).toString());
+            Object nameExpressionValue = nameExpression.getValue(planItemInstanceEntity);
+            if (nameExpressionValue != null) {
+                planItemInstanceEntity.setName(nameExpressionValue.toString());
+            }
         }
 
         if (StringUtils.isNotEmpty(stage.getBusinessStatus())) {

modules/flowable-engine/src/main/java/org/flowable/engine/delegate/DelegateExecution.java

@@ -88,6 +88,11 @@ public interface DelegateExecution extends VariableScope {
      */
     String getCurrentActivityId();
 
+    /**
+     * Gets the name of the current activity.
+     */
+    String getCurrentActivityName();
+
     /**
      * Returns the tenant id, if any is set before on the process definition or process instance.
      */

modules/flowable-engine/src/main/java/org/flowable/engine/impl/bpmn/behavior/UserTaskActivityBehavior.java

@@ -136,6 +136,9 @@ public void execute(DelegateExecution execution, MigrationContext migrationConte
             activeTaskCandidateGroups = userTask.getCandidateGroups();
             activeTaskIdVariableName = userTask.getTaskIdVariableName();
         }
+        if (execution.getCurrentActivityName() != null) {
+            activeTaskName = execution.getCurrentActivityName();
+        }
 
         CreateUserTaskBeforeContext beforeContext = new CreateUserTaskBeforeContext(userTask, execution, activeTaskName, activeTaskDescription, activeTaskDueDate, 
                         activeTaskPriority, activeTaskCategory, activeTaskFormKey, activeTaskSkipExpression, activeTaskAssignee, activeTaskOwner, 

modules/flowable-engine/src/main/java/org/flowable/engine/impl/persistence/entity/ActivityInstanceEntityManagerImpl.java

@@ -20,9 +20,11 @@
 import java.util.Map;
 import java.util.Objects;
 
+import org.apache.commons.lang3.StringUtils;
 import org.flowable.bpmn.model.FlowElement;
 import org.flowable.bpmn.model.FlowNode;
 import org.flowable.bpmn.model.SequenceFlow;
+import org.flowable.common.engine.api.delegate.Expression;
 import org.flowable.common.engine.impl.cfg.IdGenerator;
 import org.flowable.engine.history.HistoricActivityInstance;
 import org.flowable.engine.impl.ActivityInstanceQueryImpl;
@@ -350,9 +352,25 @@ protected ActivityInstanceEntity createActivityInstanceEntity(ExecutionEntity ex
         }
 
         if (execution.getCurrentFlowElement() != null) {
-            activityInstanceEntity.setActivityName(execution.getCurrentFlowElement().getName());
+            if (StringUtils.isNotEmpty(execution.getCurrentFlowElement().getName())
+                    && (execution.getCurrentFlowElement().getName().contains("${")
+                    || execution.getCurrentFlowElement().getName().contains("#{"))) {
+                Expression activityNameExpression = CommandContextUtil.getProcessEngineConfiguration().getExpressionManager()
+                        .createExpression(execution.getCurrentFlowElement().getName());
+
+                Object expressionValue = activityNameExpression.getValue(execution);
+                if (expressionValue != null) {
+                    String nameValue = expressionValue.toString();
+                    execution.setCurrentActivityName(nameValue);
+                    activityInstanceEntity.setActivityName(nameValue);
+                }
+            } else {
+                activityInstanceEntity.setActivityName(execution.getCurrentFlowElement().getName());
+            }
+
             activityInstanceEntity.setActivityType(parseActivityType(execution.getCurrentFlowElement()));
         }
+
         Date now = getClock().getCurrentTime();
         activityInstanceEntity.setStartTime(now);
 

modules/flowable-engine/src/main/java/org/flowable/engine/impl/persistence/entity/ExecutionEntity.java

@@ -155,4 +155,6 @@ public interface ExecutionEntity extends DelegateExecution, Execution, ProcessIn
     void setOriginatingCurrentFlowElement(FlowElement flowElement);
 
     List<VariableInstanceEntity> getQueryVariables();
+
+    void setCurrentActivityName(String activityName);
 }

modules/flowable-engine/src/main/java/org/flowable/engine/impl/persistence/entity/ExecutionEntityImpl.java

@@ -1294,6 +1294,10 @@ public String getCurrentActivityName() {
         return activityName;
     }
 
+    @Override
+    public void setCurrentActivityName(String activityName) {
+        this.activityName = activityName;
+    }
     @Override
     public String getStartActivityId() {
         return startActivityId;

modules/flowable-engine/src/test/java/org/flowable/engine/test/api/runtime/RuntimeActivityInstanceTest.java

@@ -520,4 +520,61 @@ public void upgradeFromHistoryToRuntimeActivities_changeOwner() {
         assertProcessEnded(processInstance.getId());
     }
 
+    @Test
+    @Deployment(resources = { "org/flowable/engine/test/api/oneTaskProcessWithExpression.bpmn20.xml" })
+    public void testActivityNameIsResolved() {
+        ProcessInstance processInstance = runtimeService.createProcessInstanceBuilder().processDefinitionKey("oneTaskProcess")
+                .variable("testVar", "someTestValue").start();
+        ActivityInstance taskActivity = runtimeService.createActivityInstanceQuery().activityId("theTask").processInstanceId(processInstance.getId())
+                .singleResult();
+        assertThat(taskActivity.getActivityName()).isEqualTo("someTestValue");
+
+        ActivityInstance flowActivityInstance = runtimeService.createActivityInstanceQuery().processInstanceId(processInstance.getId()).activityId("flow1")
+                .singleResult();
+
+        assertThat(flowActivityInstance.getActivityName()).isEqualTo("someTestValue");
+
+    }
+
+    @Test
+    @Deployment(resources = { "org/flowable/engine/test/api/runtime/ServiceTaskWithNameExpression.bpmn20.xml" })
+    public void testServiceTaskWithNameExpression() {
+        ProcessInstance processInstance = runtimeService.createProcessInstanceBuilder().processDefinitionKey("noopProcess")
+                .variable("testVar", "someTestValue").start();
+        ActivityInstance taskActivity = runtimeService.createActivityInstanceQuery().activityId("noop").processInstanceId(processInstance.getId())
+                .singleResult();
+        assertThat(taskActivity.getActivityName()).isEqualTo("someTestValue");
+
+
+    }
+
+    @Test
+    @Deployment(resources = "org/flowable/engine/test/api/oneTaskProcessWithBeanExpression.bpmn20.xml")
+    public void testTaskNameExpressionIsNotResolvedTwice() {
+        NameProvider nameProvider = new NameProvider();
+        ProcessInstance processInstance = runtimeService.createProcessInstanceBuilder().transientVariable("nameProvider", nameProvider)
+                .processDefinitionKey("oneTaskProcess").start();
+        ActivityInstance taskActivity = runtimeService.createActivityInstanceQuery().activityId("theTask").processInstanceId(processInstance.getId())
+                .singleResult();
+        Task task = taskService.createTaskQuery().processInstanceId(processInstance.getId()).singleResult();
+
+        assertThat(taskActivity.getActivityName()).isEqualTo("someName");
+        assertThat(task.getName()).isEqualTo("someName");
+        assertThat(nameProvider.getCounter()).isEqualTo(1);
+
+    }
+
+    public static class NameProvider {
+
+        int counter = 0;
+
+        public String getName() {
+            counter++;
+            return "someName";
+        }
+
+        public int getCounter() {
+            return counter;
+        }
+    }
 }

modules/flowable-engine/src/test/resources/org/flowable/engine/test/api/oneTaskProcessWithBeanExpression.bpmn20.xml

@@ -0,0 +1,18 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<definitions
+  xmlns="http://www.omg.org/spec/BPMN/20100524/MODEL"
+  xmlns:activiti="http://activiti.org/bpmn"
+  targetNamespace="ExamplesCategory">
+
+  <process id="oneTaskProcess" name="The One Task Process">
+    <documentation>This is a process for testing purposes</documentation>
+
+    <startEvent id="theStart" />
+    <sequenceFlow id="flow1"  sourceRef="theStart" targetRef="theTask" />
+    <userTask id="theTask" name="${nameProvider.getName()}" />
+    <sequenceFlow id="flow2" sourceRef="theTask" targetRef="theEnd" />
+    <endEvent id="theEnd" />
+
+  </process>
+
+</definitions>

modules/flowable-engine/src/test/resources/org/flowable/engine/test/api/oneTaskProcessWithExpression.bpmn20.xml

@@ -0,0 +1,18 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<definitions
+  xmlns="http://www.omg.org/spec/BPMN/20100524/MODEL"
+  xmlns:activiti="http://activiti.org/bpmn"
+  targetNamespace="ExamplesCategory">
+
+  <process id="oneTaskProcess" name="The One Task Process">
+    <documentation>This is a process for testing purposes</documentation>
+
+    <startEvent id="theStart" />
+    <sequenceFlow id="flow1"  name="${testVar}" sourceRef="theStart" targetRef="theTask" />
+    <userTask id="theTask" name="${testVar}" />
+    <sequenceFlow id="flow2" sourceRef="theTask" targetRef="theEnd" />
+    <endEvent id="theEnd" />
+
+  </process>
+
+</definitions>

modules/flowable-engine/src/test/resources/org/flowable/engine/test/api/runtime/ServiceTaskWithNameExpression.bpmn20.xml

@@ -0,0 +1,23 @@
+<?xml version="1.0" encoding="UTF-8"?>
+
+<definitions xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
+  xmlns="http://www.omg.org/spec/BPMN/20100524/MODEL"
+  xmlns:flowable="http://flowable.org/bpmn"
+  targetNamespace="Examples">
+
+  <process id="noopProcess">
+
+    <startEvent id="start" />
+    <sequenceFlow id="flow1" sourceRef="start" targetRef="noop" />
+
+    <serviceTask id="noop" name="${testVar}" flowable:class="org.flowable.engine.test.history.Noop" />
+    <sequenceFlow id="flow2" sourceRef="noop" targetRef="waitTask" />
+
+    <receiveTask id="waitTask"/>
+    <sequenceFlow sourceRef="waitTask" targetRef="end"/>
+
+    <endEvent id="end" />
+
+  </process>
+
+</definitions>