Expand planItemInstances keyword to support filtering based on a predicate and add information about lambda expressions in release notes

Author: filiphr

distro/src/readme.html

@@ -31,6 +31,17 @@ <h1>Flowable Release Notes</h1>
 <h3>Release Notes - Flowable - 8.0.0</h3>
 
 <ul>
+    <li>
+        The method `stream()` can be used to obtain a <code>java.util.stream.Stream</code> from a collection.
+    </li>
+    <li>
+        Lambda expressions can be used in expressions. e.g. if you have a transient list of customers you can do something like:
+        <code>${customers.stream().filter(customer -> customer.type eq 'premium').toList()}</code> to get a list of premium customers
+        or <code>${customers.stream().map(customer -> customer.name).toList()</code> to get the names of all the customers.
+    </li>
+    <li>
+        The <code>planItemInstances</code> now expose a <code>filter(Predicate&lt;DelegatePlanItemInstance&gt; predicate)</code> method that can be used to provide custom filter options.
+    </li>
     <li>
         Date variables will now include the milliseconds when they are returned over REST.
         E.g., up to now a date variable with the value of <code>2020-05-04T09:25:45.583Z</code> would have been returned as <code>2020-05-04T09:25:45Z</code>.
@@ -45,7 +56,7 @@ <h3>Release Notes - Flowable - 8.0.0</h3>
         There is still support for Jackson 2 variables.
         With Spring Boot this can be enabled by setting <code>flowable.variable-json-mapper</code> to <code>jackson2</code>.
         By default, Jackson 3 is being used for variables.
-        When configuring Flowable without Spring Boot then the <code>variableJsonMapper</code> on the process, cmmn and app engine configurations
+        When configuring Flowable without Spring Boot then the <code>variableJsonMapper</code> on the process, cmmn, and app engine configurations
         should be set to be <code>org.flowable.common.engine.impl.json.jackson2.Jackson2VariableJsonMapper</code>
         and the <code>org.flowable.common.rest.variable.Jackson2JsonObjectRestVariableConverter</code> should be added to the appropriate rest response factories.
     </li>

docs/docusaurus/docs/cmmn/ch03-API.md

@@ -234,6 +234,10 @@ To filter based on the name:
 
 -   names('name1', 'name2', 'name3')
 
+To filter using a lambda expression:
+
+-   filter(planItemInstance -> planItemInstance.name.startsWith('Service')
+
 For some use cases, the plan item instances that should be filtered should only be part of the current stage. The 'current stage' is either the parent stage of a plan item or the case instance when there’s no parent stage.
 
 -   currentStage()

modules/flowable-cmmn-engine/src/main/java/org/flowable/cmmn/engine/impl/el/PlanItemInstancesWrapper.java

@@ -16,8 +16,10 @@
 import java.util.Arrays;
 import java.util.List;
 import java.util.Objects;
+import java.util.function.Predicate;
 import java.util.stream.Collectors;
 
+import org.flowable.cmmn.api.delegate.DelegatePlanItemInstance;
 import org.flowable.cmmn.api.runtime.CaseInstance;
 import org.flowable.cmmn.api.runtime.PlanItemInstance;
 import org.flowable.cmmn.api.runtime.PlanItemInstanceState;
@@ -78,16 +80,10 @@ public PlanItemInstancesWrapper definitionId(String...ids) {
     }
 
     public PlanItemInstancesWrapper definitionIds(String...ids) {
-        ensurePlanItemInstanceInitialized();
-
         List<String> list = Arrays.asList(ids);
-        List<PlanItemInstanceEntity> filteredPlanItemInstances = planItemInstances.stream()
-            .filter(planItemInstanceEntity -> planItemInstanceEntity.getPlanItem() != null
+        return filter(planItemInstanceEntity -> planItemInstanceEntity.getPlanItem() != null
                 && planItemInstanceEntity.getPlanItem().getPlanItemDefinition() != null
-                && list.contains(planItemInstanceEntity.getPlanItem().getPlanItemDefinition().getId()))
-            .collect(Collectors.toList());
-
-        return new PlanItemInstancesWrapper(variableContainer, caseInstanceEntity, filteredPlanItemInstances);
+                && list.contains(planItemInstanceEntity.getPlanItem().getPlanItemDefinition().getId()));
     }
 
     public List<String> getDefinitionId() {
@@ -104,16 +100,11 @@ public PlanItemInstancesWrapper name(String...names) {
     }
 
     public PlanItemInstancesWrapper names(String...names) {
-        ensurePlanItemInstanceInitialized();
 
         List<String> list = Arrays.asList(names);
-        List<PlanItemInstanceEntity> filteredPlanItemInstances = planItemInstances.stream()
-            .filter(planItemInstanceEntity -> planItemInstanceEntity.getPlanItem() != null
+        return filter(planItemInstanceEntity -> planItemInstanceEntity.getPlanItem() != null
                 && planItemInstanceEntity.getPlanItem().getPlanItemDefinition() != null
-                && list.contains(planItemInstanceEntity.getPlanItem().getPlanItemDefinition().getName()))
-            .collect(Collectors.toList());
-
-        return new PlanItemInstancesWrapper(variableContainer, caseInstanceEntity, filteredPlanItemInstances);
+                && list.contains(planItemInstanceEntity.getPlanItem().getPlanItemDefinition().getName()));
     }
 
     public List<String> getDefinitionName() {
@@ -193,25 +184,23 @@ public PlanItemInstancesWrapper asyncActiveLeave() {
     }
 
     public PlanItemInstancesWrapper onlyTerminal() {
-        ensurePlanItemInstanceInitialized();
-
-        List<PlanItemInstanceEntity> filteredPlanItemInstances = planItemInstances.stream()
-            .filter(planItemInstanceEntity -> planItemInstanceEntity.getPlanItem() != null
+        return filter(planItemInstanceEntity -> planItemInstanceEntity.getPlanItem() != null
                 && planItemInstanceEntity.getPlanItem().getPlanItemDefinition() != null
-                && PlanItemInstanceState.isInTerminalState(planItemInstanceEntity))
-            .collect(Collectors.toList());
-
-        return new PlanItemInstancesWrapper(variableContainer, caseInstanceEntity, filteredPlanItemInstances);
+                && PlanItemInstanceState.isInTerminalState(planItemInstanceEntity));
     }
 
     public PlanItemInstancesWrapper onlyNonTerminal() {
+        return filter(planItemInstanceEntity -> planItemInstanceEntity.getPlanItem() != null
+                && planItemInstanceEntity.getPlanItem().getPlanItemDefinition() != null
+                && !PlanItemInstanceState.isInTerminalState(planItemInstanceEntity));
+    }
+
+    public PlanItemInstancesWrapper filter(Predicate<DelegatePlanItemInstance> filter) {
         ensurePlanItemInstanceInitialized();
 
         List<PlanItemInstanceEntity> filteredPlanItemInstances = planItemInstances.stream()
-            .filter(planItemInstanceEntity -> planItemInstanceEntity.getPlanItem() != null
-                && planItemInstanceEntity.getPlanItem().getPlanItemDefinition() != null
-                && !PlanItemInstanceState.isInTerminalState(planItemInstanceEntity))
-            .collect(Collectors.toList());
+                .filter(filter)
+                .collect(Collectors.toList());
 
         return new PlanItemInstancesWrapper(variableContainer, caseInstanceEntity, filteredPlanItemInstances);
     }
@@ -224,13 +213,7 @@ public List<PlanItemInstanceEntity> getList() {
     // Helper methods
 
     protected PlanItemInstancesWrapper getPlanItemInstancesWithState(String state) {
-        ensurePlanItemInstanceInitialized();
-
-        List<PlanItemInstanceEntity> filteredPlanItemInstances = planItemInstances.stream()
-            .filter(planItemInstanceEntity -> Objects.equals(state, planItemInstanceEntity.getState()))
-            .collect(Collectors.toList());
-
-        return new PlanItemInstancesWrapper(variableContainer, caseInstanceEntity, filteredPlanItemInstances);
+        return filter(planItemInstanceEntity -> Objects.equals(state, planItemInstanceEntity.getState()));
     }
 
     protected List<PlanItemInstanceEntity> collectAllChildPlanItemInstances(PlanItemInstanceContainer planItemInstanceContainer) {

modules/flowable-cmmn-engine/src/test/java/org/flowable/cmmn/test/el/PlanItemInstancesKeyWordInExpressionsTest.java

@@ -144,6 +144,18 @@ public void testWithName() {
         assertThat(evaluateExpression(caseInstance.getId(), "${planItemInstances.name('invalid', 'A').count()}")).isEqualTo(1);
     }
 
+    @Test
+    @CmmnDeployment(resources = "org/flowable/cmmn/test/el/PlanItemInstancesKeyWordInExpressionsTest.testWithName.cmmn")
+    public void testWithFilterUsingLambda() {
+        CaseInstance caseInstance = cmmnRuntimeService.createCaseInstanceBuilder()
+                .caseDefinitionKey("testPlanItemInstancesKeyWord").start();
+
+        assertThat(evaluateExpression(caseInstance.getId(), "${planItemInstances.count()}")).isEqualTo(8);
+        assertThat(evaluateExpression(caseInstance.getId(), "${planItemInstances.filter(inst -> inst.name eq 'A' or inst.name eq 'B').count()}")).isEqualTo(2);
+
+        assertThat(evaluateExpression(caseInstance.getId(), "${planItemInstances.filter(inst -> inst.name eq 'invalid').count()}")).isEqualTo(0);
+    }
+
     @Test
     @CmmnDeployment
     public void testWithStateAndId() {