Bpmn.js 进阶指南之原理分析与模块改造

import {
  is
} from 'bpmn-js/lib/util/ModelUtil';
 
import {
  getBusinessObject
} from 'bpmn-js/lib/util/ModelUtil';
 
import {
  add as collectionAdd,
  remove as collectionRemove
} from 'diagram-js/lib/util/Collections';
 
import {
  getExtensionElementsList
} from 'bpmn-js/lib/properties-panel/util/ExtensionElementsUtil';
 
import {
  isArray
} from 'min-dash';
 
// 示例：向元素添加自定义扩展属性
function addCustomExtension(element, bpmnFactory, extensionType) {
  const businessObject = getBusinessObject(element);
 
  return bpmnFactory.create(extensionType, {
    values: []
  }).then(extensionElements => {
    return getExtensionElementsList(businessObject, extensionType, true).then(extensionElementsList => {
      if (!extensionElementsList) {
        // 如果没有扩展元素，则创建一个新的扩展元素集合
        return bpmnFactory.create('bpmn:ExtensionElements', {
          values: [extensionElements]
        }).then(extensionElements => {
          return bpmnFactory.create('bpmn:Documentation', {
            text: '自定义扩展属性'
          }).then(documentation => {
            // 将文档添加到扩展元素集合中
            collectionAdd(extensionElements.get('values'), documentation);
            // 将扩展元素集合添加到业务对象中
            return businessObject.set('extensionElements', extensionElements);
          });
        });
      }
 
      // 如果已经有扩展元素，直接添加新的扩展元素
      collectionAdd(extensionElementsList, extensionElements);
      return businessObject.set('extensionElements', businessObject.get('extensionElements'));
    });
  });
}
 
// 示例：从元素中移除自定义扩展属性
function removeCustomExtension(element, bpmnFactory, extensionType) {
  const businessObject = getBusinessObject(element);
 
  return getExtensionElementsList(businessObject, extensionType).then(extensionElementsList => {
    if (isArray(extensionElementsList)) {
      // 移除所有的自定义扩展属性
      extensionElementsList.forEach(extensionElements => {
        collectionRemove(extensionElements.get('values'), extensionElements => {
          return is(extensionElements, 'bpmn:ExtensionElements') &&
            !extensionElements.get('values').length;
        });
      });
 
      // 移除扩展元素集合
      businessObject.set('extensionElements', null);
    }
  });
}
 
// 使用示例
// 假设 element, bpmnFactory 已经定义且初始化
addCustomExtension(