vue引用bpmn.js实现流程图

npm安装bpmn

npm install bpmn-js --save

页面引用

<template>
  <div class="containers">
    <div class="loading" v-if="loading">Loading...</div>
    <template v-else>
      <div class="canvas" ref="canvas"></div>
      <div id="js-properties-panel" class="panel"></div>
      <ul class="buttons">
        <li>
          <a ref="saveDiagram" href="javascript:" title="保存为bpmn"
            >保存为bpmn</a
          >
        </li>
        <li>
          <a ref="saveSvg" href="javascript:" title="保存为svg">保存为svg</a>
        </li>
      </ul>
    </template>
  </div>
</template>

<script>
// 引入相关的依赖
import BpmnModeler from "bpmn-js/lib/Modeler";
import axios from "axios";
import { xmlStr } from "../mock/xmlStr";

import "bpmn-js/dist/assets/diagram-js.css"; // 左边工具栏以及编辑节点的样式
import "bpmn-js/dist/assets/bpmn-font/css/bpmn.css";
import "bpmn-js/dist/assets/bpmn-font/css/bpmn-codes.css";
import "bpmn-js/dist/assets/bpmn-font/css/bpmn-embedded.css";
import "bpmn-js-properties-panel/dist/assets/bpmn-js-properties-panel.css"; // 右边工具栏样式

export default {
  name: "",
  components: {},
  // 生命周期 - 创建完成（可以访问当前this实例）
  created() {},
  // 生命周期 - 载入后, Vue 实例挂载到实际的 DOM 操作完成，一般在该过程进行 Ajax 交互
  mounted() {
    this.init();
  },
  data() {
    return {
      // bpmn建模器
      bpmnModeler: null,
      container: null,
      canvas: null,
      loading: true,
      xmlUrl: "",
      defaultXmlStr: xmlStr,
    };
  },
  // 方法集合
  methods: {
    async init() {
      this.loading = true;
      this.xmlUrl = await this.getXmlUrl();
      console.log(this.xmlUrl);
      this.loading = false;
      this.$nextTick(() => {
        this.initBpmn();
      });
    },
    getXmlUrl() {
      return new Promise((resolve) => {
        setTimeout(() => {
          // const url = 'https://hexo-blog-1256114407.cos.ap-shenzhen-fsi.myqcloud.com/mock1.bpmn'
          const url = "";
          resolve(url);
        }, 1000);
      });
    },
    initBpmn() {
      // 获取到属性ref为“canvas”的dom节点
      const canvas = this.$refs.canvas;
      // 建模
      this.bpmnModeler = new BpmnModeler({
        container: canvas,
      });
      this.createNewDiagram();
    },
    async createNewDiagram() {
      const that = this;
      let bpmnXmlStr = "";
      if (this.xmlUrl === "") {
        bpmnXmlStr = this.defaultXmlStr;
        this.transformCanvas(bpmnXmlStr);
      } else {
        let res = await axios({
          method: "get",
          timeout: 120000,
          url: that.xmlUrl,
          headers: { "Content-Type": "multipart/form-data" },
        });
        console.log(res);
        bpmnXmlStr = res["data"];
        this.transformCanvas(bpmnXmlStr);
      }
    },
    // 将字符串转换成图并渲染
    transformCanvas(bpmnXmlStr) {
      this.bpmnModeler.importXML(bpmnXmlStr, (err) => {
        if (err) {
          console.error(err);
        } else {
          this.success();
        }
        // 让图能自适应屏幕
        this.bpmnModeler.get("canvas").zoom("fit-viewport");
      });
    },
    success() {
      console.log("创建成功!");
      this.addBpmnListener();
      this.addModelerListener();
    },
    // 添加绑定事件
    addBpmnListener() {
      const that = 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 () {
        that.saveSVG(function (err, svg) {
          that.setEncoded(downloadSvgLink, "diagram.svg", err ? null : svg);
        });
        that.saveDiagram(function (err, xml) {
          that.setEncoded(downloadLink, "diagram.bpmn", err ? null : xml);
        });
      });
    },
    addModelerListener() {
      // 监听 modeler
      const bpmnjs = this.bpmnModeler;
      const that = this;
      const events = [
        "shape.added",
        "shape.move.end",
        "connect.end",
        "connection.create",
        "connection.move",
      ];
      events.forEach(function (event) {
        that.bpmnModeler.on(event, (e) => {
          console.log(event, e);
          var elementRegistry = bpmnjs.get("elementRegistry");
          var shape = e.element ? elementRegistry.get(e.element.id) : e.shape;
          console.log(shape);
        });
      });
    },
    // 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bpmn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);
      // 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
      console.log(link, name, data);
      let xmlFile = new File([data], "test.bpmn");
      console.log(xmlFile);
      if (data) {
        link.className = "active";
        link.href = "data:application/bpmn20-xml;charset=UTF-8," + encodedData;
        link.download = name;
      }
    },
  },
  // 计算属性
  computed: {},
};
</script>

<style scoped>
.loading {
  font-size: 26px;
}
.containers {
  background-color: #ffffff;
  width: 100%;
  height: calc(100vh - 52px);
}
.canvas {
  width: 100%;
  height: 100%;
}
.panel {
  position: absolute;
  right: 0;
  top: 0;
  width: 300px;
}
.buttons {
  position: absolute;
  left: 20px;
  bottom: 20px;
}
.buttons li {
  display: inline-block;
  margin: 5px;
}
.buttons li a {
  color: #999;
  background: #eee;
  cursor: not-allowed;
  padding: 8px;
  border: 1px solid #ccc;
  text-decoration: none;
}
.buttons li a.active {
  color: #333;
  background: #fff;
  cursor: pointer;
}
</style>

smlStr.js

export var xmlStr = `<?xml version="1.0" encoding="UTF-8"?>
<definitions xmlns="http://www.omg.org/spec/BPMN/20100524/MODEL" xmlns:bpmndi="http://www.omg.org/spec/BPMN/20100524/DI" xmlns:omgdi="http://www.omg.org/spec/DD/20100524/DI" xmlns:omgdc="http://www.omg.org/spec/DD/20100524/DC" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" id="sid-38422fae-e03e-43a3-bef4-bd33b32041b2" targetNamespace="http://bpmn.io/bpmn" exporter="bpmn-js (https://demo.bpmn.io)" exporterVersion="5.1.2">
<process id="Process_1" isExecutable="false">
    <startEvent id="StartEvent_1y45yut" name="开始">
    <outgoing>SequenceFlow_0h21x7r</outgoing>
    </startEvent>
    <task id="Task_1hcentk">
    <incoming>SequenceFlow_0h21x7r</incoming>
    </task>
    <sequenceFlow id="SequenceFlow_0h21x7r" sourceRef="StartEvent_1y45yut" targetRef="Task_1hcentk" />
</process>
<bpmndi:BPMNDiagram id="BpmnDiagram_1">
    <bpmndi:BPMNPlane id="BpmnPlane_1" bpmnElement="Process_1">
    <bpmndi:BPMNShape id="StartEvent_1y45yut_di" bpmnElement="StartEvent_1y45yut">
        <omgdc:Bounds x="152" y="102" width="36" height="36" />
        <bpmndi:BPMNLabel>
        <omgdc:Bounds x="160" y="145" width="22" height="14" />
        </bpmndi:BPMNLabel>
    </bpmndi:BPMNShape>
    <bpmndi:BPMNShape id="Task_1hcentk_di" bpmnElement="Task_1hcentk">
        <omgdc:Bounds x="240" y="80" width="100" height="80" />
    </bpmndi:BPMNShape>
    <bpmndi:BPMNEdge id="SequenceFlow_0h21x7r_di" bpmnElement="SequenceFlow_0h21x7r">
        <omgdi:waypoint x="188" y="120" />
        <omgdi:waypoint x="240" y="120" />
    </bpmndi:BPMNEdge>
    </bpmndi:BPMNPlane>
</bpmndi:BPMNDiagram>
</definitions>`

效果图

image.png