Notes on implementation and acquisition of flowable custom attributes

flowable Custom properties

Recently in the project , Need to use workflow , The use of flowable Open source framework for development . There is a requirement in the project to add a custom attribute on the process node . Spent some time on it , In case you forget , Take notes .

edit stencilset_bpmn.json file

find stencilset_bpmn.json file , Open it and you will find propertyPackages Properties of , Pictured ：

We just need to follow the form created before the process , I define it here as follows ：

{
    
      "name": "isbatchapproval_package",
      "properties": [
        {
    
          "id": "isbatchapproval",
          "type": "Boolean",  // Set to boolean type 
          "title": " Allow batch approval ",
          "value": "",
          "description": " Set whether batch approval is allowed for related nodes ",
          "popular": true
        }
      ]
    }

After writing , To display related attributes on related nodes , You need to reference the above attributes on the node id The value is isbatchapproval Of , Because batch approval is only for user task nodes , So in UserTask Introduction in , as follows ：

{
    
      "type": "node",
      "id": "UserTask",
      "title": "\u7528\u6237\u4efb\u52a1",
      ...
      "propertyPackages": [
        ...
        "isbatchapproval_package",  // Here corresponds to the above defined isbatchapproval_package, If you want to add it after the specified attribute , Only need to isbatchapproval_package Put it after the specified attribute introduction 
        ...
      ],
      ...
    },

Click the user node in the process design diagram to add the following attributes ：

In download BPMN.xml Add attributes in

By the above operation , It can only be displayed on the process design , But when you save it , Downloaded after release bpmn.xml There will be no such attribute in the file , We need to do the following now
1. Create a IsBatchApprovalJsonConver.java Integrate UserTaskJsonConverter, The main codes are as follows ：

 @Override
    protected FlowElement convertJsonToElement(JsonNode elementNode, JsonNode modelNode,
                                               Map<String, JsonNode> shapeMap) {
    
        UserTask flowElement = (UserTask) super.convertJsonToElement(elementNode, modelNode, shapeMap);
        List<CustomProperty> customProperties = new ArrayList<>();
        //  Extend batch approval attribute , Into the process designer property value , This place can add more 
        Boolean isBatchApproval = getPropertyValueAsBoolean("isbatchapproval", elementNode);
        if (Objects.nonNull(isBatchApproval)) {
    
            CustomProperty nodeType = this.createProperty("isbatchapproval", isBatchApproval.toString());
            customProperties.add(nodeType);
        }
        
        if (CollUtil.isNotEmpty(customProperties)) {
    
            // Add properties to the process designer 
            flowElement.setCustomProperties(customProperties);
        }
        return flowElement;
    }

    @Override
    protected void convertElementToJson(ObjectNode propertiesNode, BaseElement baseElement) {
    
        super.convertElementToJson(propertiesNode, baseElement);
    }

    /** *  Create custom properties  * * @param propertyName  The attribute name  * @param propertyValue  Property value  */
    private CustomProperty createProperty(String propertyName, String propertyValue) {
    
        CustomProperty customProperty = new CustomProperty();
        customProperty.setId(propertyName);
        customProperty.setName(propertyName);
        customProperty.setSimpleValue(propertyValue);
        return customProperty;
    }

2. establish CustomPropertyInit.java, And add it to the process design configuration , The code is as follows ：

public CustomPropertyInit() {
    
        Map<Class<? extends BaseElement>, Class<? extends BaseBpmnJsonConverter>> convertersToJsonMap = BpmnJsonConverter.convertersToJsonMap;
        Map<String, Class<? extends BaseBpmnJsonConverter>> convertersToBpmnMap = BpmnJsonConverter.convertersToBpmnMap;
        //  Add custom tasks json converter 
        IsBatchApprovalJsonConver.setCustomTypes(convertersToBpmnMap, convertersToJsonMap);
    }

/*** *  Added in the process design configuration class  */
@Bean
public CustomPropertyInit createCustomPropertyInit() {
    
    return new CustomPropertyInit();
}

This redeploys the process , download bpmn You can see the correlation as follows , Mine is like this ：

  <flowable:isbatchapproval>true</flowable:isbatchapproval>

It shows that the custom attribute is successful .

flowable Get the value of the custom property

We set the relevant custom attributes in the front-end process , How do we get isbatchapproval What about this property ？ Just use the following code ：

public FlowElement getFlowElementByActivityIdAndProcessDefinitionId(String taskDefinedKey, String processDefinitionId) {
    
        BpmnModel bpmnModel = repositoryService.getBpmnModel(processDefinitionId);
        List<Process> processes = bpmnModel.getProcesses();
        if (CollectionUtils.isNotEmpty(processes)) {
    
            for (Process process : processes) {
    
                FlowElement flowElement = process.getFlowElement(activityId, true);
                if (Objects.nonNull(flowElement)) {
    
                    return flowElement;
                }
            }
        }
        return null;
    }

    public List<ExtensionElement> getCustomProperty(String taskDefinedKey, String processDefinitionId, String customPropertyName) {
    
        FlowElement flowElement = this.getFlowElementByActivityIdAndProcessDefinitionId(activityId, processDefinitionId);
        if (flowElement != null && flowElement instanceof UserTask) {
    
            UserTask userTask = (UserTask) flowElement;
            Map<String, List<ExtensionElement>> extensionElements = userTask.getExtensionElements();
            if (MapUtils.isNotEmpty(extensionElements)) {
    
                List<ExtensionElement> values = extensionElements.get(customPropertyName);
                if (CollectionUtils.isNotEmpty(values)) {
    
                    return values;
                }
            }
        }
        return null;
    }

This requires process definition ID And the definition of the task key,getCustomProperty Method needs to pass in the attribute name to query .
My call is as follows ：

Task task = taskQueryUtils.queryTaskToById(taskId);
// Get the custom batch attribute value 
List<ExtensionElement> = taskQueryUtils.getCustomProperty(task.getTaskDefinitionKey(), task.getProcessDefinitionId(), "isbatchapproval");

ExtensionElement One of the objects is ElementText attribute , This attribute is the value of this attribute .