js 实现bpmn
BPMN 实现基础
BPMN(Business Process Model and Notation)是一种业务流程建模标准,用于图形化描述业务流程。在JavaScript中实现BPMN通常需要使用专门的库或框架,如bpmn-js。
使用 bpmn-js 库
bpmn-js是一个基于BPMN 2.0的开源工具包,提供建模器和查看器功能。以下是一个简单的实现示例:
安装依赖:
npm install bpmn-js
基础代码示例:
import BpmnModeler from 'bpmn-js/lib/Modeler';
const modeler = new BpmnModeler({
container: '#canvas',
keyboard: {
bindTo: document
}
});
async function createNewDiagram() {
try {
const result = await modeler.createDiagram();
console.log('Diagram created');
} catch (err) {
console.error('Error creating diagram', err);
}
}
createNewDiagram();
自定义建模器
可以通过扩展bpmn-js来实现自定义建模功能:
import { inject } from 'bpmn-js/lib/Modeler';
function CustomModeling(eventBus, elementFactory) {
inject(this, eventBus, elementFactory);
this.createShape = function(type, position) {
const shape = this.elementFactory.createShape({ type });
this.eventBus.fire('shape.create', { shape, position });
return shape;
};
}
const modeler = new BpmnModeler({
container: '#canvas',
additionalModules: [CustomModeling]
});
集成属性面板
为BPMN元素添加属性编辑功能:
import PropertiesPanelModule from 'bpmn-js-properties-panel';
import PropertiesProviderModule from 'bpmn-js-properties-panel/lib/provider/camunda';
const modeler = new BpmnModeler({
container: '#canvas',
propertiesPanel: {
parent: '#properties'
},
additionalModules: [
PropertiesPanelModule,
PropertiesProviderModule
]
});
保存和加载BPMN
实现BPMN图的保存和加载功能:
async function saveXML() {
try {
const { xml } = await modeler.saveXML({ format: true });
console.log('BPMN XML:', xml);
return xml;
} catch (err) {
console.error('Error saving diagram', err);
}
}
async function loadXML(xml) {
try {
await modeler.importXML(xml);
console.log('Diagram loaded');
} catch (err) {
console.error('Error loading diagram', err);
}
}
事件处理
监听BPMN元素的事件:
modeler.on('element.click', function(event) {
const element = event.element;
console.log('Element clicked:', element.id, element.type);
});
modeler.on('selection.changed', function(event) {
const newSelection = event.newSelection;
console.log('Selection changed:', newSelection);
});
样式定制
自定义BPMN元素的样式:
modeler.get('canvas').addMarker('someElementId', 'highlight');
modeler.get('canvas').removeMarker('someElementId', 'highlight');
modeler.get('styles').setStyle([ 'someElementId' ], {
fill: '#f8f8f8',
stroke: '#00ff00',
strokeWidth: 2
});
扩展BPMN元素
添加自定义BPMN元素类型:
import { assign } from 'min-dash';
function CustomRenderer(eventBus, styles) {
this.drawShape = function(parentGfx, element) {
const rect = styles.rect(assign({}, element, {
fill: 'yellow',
stroke: 'red'
}));
parentGfx.appendChild(rect);
return rect;
};
}
CustomRenderer.$inject = [ 'eventBus', 'styles' ];
const modeler = new BpmnModeler({
container: '#canvas',
additionalModules: [ CustomRenderer ]
});
以上代码示例展示了如何使用JavaScript实现BPMN功能,包括基础建模、自定义扩展、属性编辑和事件处理等核心功能。实际应用中可以根据需求进一步扩展和定制。







