Angular2/打字稿和SSE(EventSource) [英] Angular2/typescript and SSE (EventSource)

问题描述

首先，我对ng2和打字稿很陌生.

First of all, I`m quite new to ng2 and typescript.

Im试图完成的工作是在Angular2组件中实现Server-Sent事件. 我已经按照此处早期文章中提到的示例进行操作，但是我的问题是无法识别"EventSource"对象(VS代码中的红色下划线).

What Im trying to accomplish is to implement Server-Sent events in Angular2 component. I have followed the examples mentioned in earlies posts here, but my problem is that the "EventSource" object is unrecognized (red underline, in VS Code).

我不确定我是否缺少一些参考资料... 我的参考是:

Im not sure if I`m missing some references... My references are:

<!-- IE required polyfills, in this exact order -->
  <script src="node_modules/es6-shim/es6-shim.min.js"></script>
  <script src="node_modules/systemjs/dist/system-polyfills.js"></script>
  <script src="node_modules/angular2/es6/dev/src/testing/shims_for_IE.js"></script>
  <script src="node_modules/angular2/bundles/angular2-polyfills.js"></script>
  <script src="node_modules/systemjs/dist/system.src.js"></script>
  <script src="node_modules/rxjs/bundles/Rx.js"></script>
  <script src="node_modules/angular2/bundles/angular2.dev.js"></script>

这是我如何植入事件源客户端的方法:

This is how I have Implemeted the eventsource client:

   ngOnInit() {
      const observable = Observable.create(observer => {
        const eventSource = new EventSource(/API_URL); //Cannot find EventSource
        eventSource.onmessage = x => observer.next(x.data);
        eventSource.onerror = x => observer.error(x);

        return () => {
            eventSource.close();
        };
    });

    observable.subscribe({
        next: guid => {
            this.zone.run(() => this.someStrings.push(guid));
        },
        error: err => console.error('something wrong occurred: ' + err)
    });

推荐答案

实际上，TypeScript中有两件事:

In fact, there are two things in TypeScript:

• 编译时间.编译器检查语法错误和类型.关于类型，它依赖于d.ts文件，该文件可以在描述对象/类合同的文件中看到.
• 执行时间.如果对象存在于您的执行环境中，则将执行代码.

• The compilation time. The compiler checks for syntax errors and types. Regarding types, it relies on d.ts files that can be seen at files described contracts of objects / classes.
• The execution time. If the object is present into your execution environment, the code will be executed.

在您的情况下，问题出在编译时.

In your case, the problem is at compilation time.

这里是EventSource的d.ts文件的示例: https://github.com/sbergot/orgmodeserver/blob/master/src/ts/deps/EventSource.d.ts

Here is a sample of d.ts file for EventSource: https://github.com/sbergot/orgmodeserver/blob/master/src/ts/deps/EventSource.d.ts

您可以通过以下方式在TypeScript文件的开头获取并引用它:

You can get it and reference it at the very beginning of your TypeScript file this way:

/// <reference path="../<path-to>EventSource.d.ts"/>

这篇关于Angular2/打字稿和SSE(EventSource)的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！