worker在Typescript的使用

業務需求是在前端顯示報表，但是sharepoint online無法直接用數據庫，只能調REST API在前端顯示

一、內嵌worker

       此方法優點是瀏覽器不用每次去加載你所寫的worker.js

 this.domElement.innerHTML=`<p>Worker 花費時間: <output id="result"></output></p>
    <button >開始 Worker</button> 
<button >開始主線程</button>
<p>原花費時間: <output id="result1"></output></p>
<canvas id="mychart"></canvas>
//插入的worker
<script id='worker1'  type="javascript/worker">

var a;
function groupBy(array, f) {
    const groups = {};
    array.forEach(function (o) {
        const group = JSON.stringify(f(o));
        groups[group] = groups[group] || [];
        groups[group].push(o);
    });
    return Object.keys(groups).map(function (group) {
        return groups[group];
    });
  }
addEventListener('message', (message) => {
    var status;
    var st = new Date();
    var xLabel=[],ylabel=[];
        groupBy(message.data,(t)=>{
            return t.country
        }).forEach(function(e){
           xLabel.push(e[0].country);
           var sum=0;
           e.forEach(element => {
               sum+=element.cost;
           });
           ylabel.push(sum);
        })
       
    status = (new Date().getTime() - st.getTime()) + ' ms';
  
 
    postMessage("time :"+status) ;
});
</script>`;

下面通過新建worker來調用，

var blob = new Blob([document.querySelector('#worker1').textContent]);
    const worker = new Worker(window.URL.createObjectURL(blob));
    worker.addEventListener('message', message => {
        document.getElementById('result').innerHTML=message.data;
    });
    this.domElement.getElementsByTagName('button').item(0).addEventListener('click',function(){
      worker.postMessage(c);
    })

二、調用外部worker.js文件

編寫js文件

var a;
function groupBy(array, f) {
    debugger;
    const groups = {};
    array.forEach(function (o) {
        const group = JSON.stringify(f(o));
        groups[group] = groups[group] || [];
        groups[group].push(o);
    });
    return Object.keys(groups).map(function (group) {
        return groups[group];
    });
  }
addEventListener('message', (message) => {
    var status;
    var st = new Date();
    var xLabel=[],ylabel=[];
        groupBy(message.data,(t)=>{
            return t.country
        }).forEach(function(e){
           xLabel.push(e[0].country);
           var sum=0;
           e.forEach(element => {
               sum+=element.cost;
           });
           ylabel.push(sum);
        })
       
    status = (new Date().getTime() - st.getTime()) + ' ms';
  
 
    postMessage("time :"+status) ;
});

聲明file-loaderfile-loader把js加載到服務器此文件爲file-loader.d.ts文件，typescript會進行編譯根據此js加載

declare module "file-loader?name=[name].js!*" {
    const value: string;
    export = value;
}

聲明創建worker

import * as workerPath from "file-loader?name=[name].js!./test.worker";
const worker = new Worker(workerPath);

console.log(workerPath, worker);
worker.addEventListener('message', message => {
    console.log(message);
});
worker.postMessage('this is a test message to the worker');