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在vue中使用bpmn-js(二)

2.新建空的图,功能要求:
① 空的,能自己画;
② 以SVG image格式、BPMN diagram格式下载在本地;

参考链接:(其实就是理解它的思路,把jQuery转化成vue)
https://github.com/bpmn-io/bpmn-js-examples/blob/master/properties-panel/app/index.html
https://github.com/bpmn-io/bpmn-js-examples/blob/master/properties-panel/app/index.js

html:
<template>
  <div class="containers" ref="content">
    <div class="canvas" ref="canvas"></div>
    <div id="js-properties-panel" class="panel"></div>
    <ul class="buttons">
      <li>下载</li>
      <li>
        <a ref="saveDiagram" href="javascript:" title="download BPMN diagram">BPMN diagram</a>
      </li>
      <li>
        <a ref="saveSvg" href="javascript:" title="download as SVG image">SVG image</a>
      </li>
    </ul>
  </div>
</template>
js:
// 引入相关的依赖
// import BpmnViewer from 'bpmn-js'
import BpmnModeler from 'bpmn-js/lib/Modeler'
import propertiesPanelModule from 'bpmn-js-properties-panel'
import propertiesProviderModule from 'bpmn-js-properties-panel/lib/provider/camunda'
import camundaModdleDescriptor from 'camunda-bpmn-moddle/resources/camunda'

export default {
  data () {
    return {
      // bpmn建模器
      bpmnModeler: null,
      container: null,
      canvas: null,
      xmlStr: null,
      processName: ''
    }
  },
  methods: {
    createNewDiagram () {
      const bpmnXmlStr = '<?xml version="1.0" encoding="UTF-8"?>\n' +
        '<bpmn2:definitions xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:bpmn2="http://www.omg.org/spec/BPMN/20100524/MODEL" xmlns:bpmndi="http://www.omg.org/spec/BPMN/20100524/DI" xmlns:dc="http://www.omg.org/spec/DD/20100524/DC" xmlns:di="http://www.omg.org/spec/DD/20100524/DI" xsi:schemaLocation="http://www.omg.org/spec/BPMN/20100524/MODEL BPMN20.xsd" id="sample-diagram" targetNamespace="http://bpmn.io/schema/bpmn">\n' +
        '  <bpmn2:process id="Process_1" isExecutable="false">\n' +
        '    <bpmn2:startEvent id="StartEvent_1"/>\n' +
        '  </bpmn2:process>\n' +
        '  <bpmndi:BPMNDiagram id="BPMNDiagram_1">\n' +
        '    <bpmndi:BPMNPlane id="BPMNPlane_1" bpmnElement="Process_1">\n' +
        '      <bpmndi:BPMNShape id="_BPMNShape_StartEvent_2" bpmnElement="StartEvent_1">\n' +
        '        <dc:Bounds height="36.0" width="36.0" x="412.0" y="240.0"/>\n' +
        '      </bpmndi:BPMNShape>\n' +
        '    </bpmndi:BPMNPlane>\n' +
        '  </bpmndi:BPMNDiagram>\n' +
        '</bpmn2:definitions>'
      // 将字符串转换成图显示出来
      this.bpmnModeler.importXML(bpmnXmlStr, function (err) {
        if (err) {
          console.error(err)
        }
      })
    },
    // 下载为SVG格式,done是个函数,调用的时候传入的
    saveSVG (done) {
      // 把传入的done再传给bpmn原型的saveSVG函数调用
      this.bpmnModeler.saveSVG(done)
    },
    // 下载为SVG格式,done是个函数,调用的时候传入的
    saveDiagram (done) {
      // 把传入的done再传给bpmn原型的saveXML函数调用
      this.bpmnModeler.saveXML({ format: true }, function (err, xml) {
        done(err, xml)
      })
    },
    // 当图发生改变的时候会调用这个函数,这个data就是图的xml
    setEncoded (link, name, data) {
      // 把xml转换为URI,下载要用到的
      const encodedData = encodeURIComponent(data)
      // 获取到图的xml,保存就是把这个xml提交给后台
      this.xmlStr = data
      // 下载图的具体操作,改变a的属性,className令a标签可点击,href令能下载,download是下载的文件的名字
      if (data) {
        link.className = 'active'
        link.href = 'data:application/bpmn20-xml;charset=UTF-8,' + encodedData
        link.download = name
      }
    }
  },
  mounted () {
    // 获取到属性ref为“content”的dom节点
    this.container = this.$refs.content
    // 获取到属性ref为“canvas”的dom节点
    const canvas = this.$refs.canvas

    // 建模,官方文档这里讲的很详细
    this.bpmnModeler = new BpmnModeler({
      container: canvas,
      // 添加控制板
      propertiesPanel: {
        parent: '#js-properties-panel'
      },
      additionalModules: [
        // 左边工具栏以及节点
        propertiesProviderModule,
        // 右边的工具栏
        propertiesPanelModule
      ],
      moddleExtensions: {
        camunda: camundaModdleDescriptor
      }
    })

    // 下载画图
    let _this = this
    // 获取a标签dom节点
    const downloadLink = this.$refs.saveDiagram
    const downloadSvgLink = this.$refs.saveSvg
    // 给图绑定事件,当图有发生改变就会触发这个事件
    this.bpmnModeler.on('commandStack.changed', function () {
      _this.saveSVG(function (err, svg) {
        _this.setEncoded(downloadSvgLink, 'diagram.svg', err ? null : svg)
      })

      _this.saveDiagram(function (err, xml) {
        _this.setEncoded(downloadLink, 'diagram.bpmn', err ? null : xml)
      })
    })

    this.createNewDiagram(this.bpmnModeler)
  }
}
css:

<style lang="scss">
  .containers{
    position: absolute;
    background-color: #ffffff;
    width: 100%;
    height: 90%;
  }
  .canvas{
    width: 100%;
    height: 100%;
  }
  .panel{
    position: absolute;
    right: 0;
    top: 0;
    width: 300px;
  }
  .buttons{
    position: absolute;
    left: 20px;
    bottom: 20px;
    &>li{
      display:inline-block;margin: 5px;
      &>a{
        color: #999;
        background: #eee;
        cursor: not-allowed;
        padding: 8px;
        border: 1px solid #ccc;
        &.active{
          color: #333;
          background: #fff;
          cursor: pointer;
        }
      }
    }
  }
</style>


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