First of all, I`m quite new to ng2 and typescript.
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).
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>
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)
});
In fact, there are two things in TypeScript:
d.ts
files that can be seen at files described contracts of objects / classes.In your case, the problem is at compilation time.
Here is a sample of d.ts file for EventSource: https://github.com/sbergot/orgmodeserver/blob/master/src/ts/deps/EventSource.d.ts
You can get it and reference it at the very beginning of your TypeScript file this way:
/// <reference path="../<path-to>EventSource.d.ts"/>