Angular2 RxJS getting 'Observable_1.Observable

问题:

I'm using AngularJS 2 Beta 0 and I'm trying to create an RxJS Observable from an event on a window object. I believe I know the formula for capturing the event as an Observable in my service:

var observ = Observable.fromEvent(this.windowHandle, 'hashchange');

The problem is that every time I try run this code, I get an error stating that 'fromEvent' is not a function.

Uncaught EXCEPTION: Error during evaluation of "click"
ORIGINAL EXCEPTION: TypeError: Observable_1.Observable.fromEvent is not a function

This seems to imply to me that I'm not handling my import correctly now that RxJS is not included in the build of Angular 2, though the rest of my application functions properly, which to me means that RxJS is where it is supposed to be.

My import in the service looks like this:

import {Observable} from 'rxjs/Observable';

Though I have also tried to use this instead (with the appropriate changes to the code), with the same results:

import {FromEventObservable} from 'rxjs/observable/fromEvent';

I have the following configuration in my Index.html:

<script>
    System.config({
        map: {
            rxjs: 'node_modules/rxjs'
        },
        packages: {
            'app': {defaultExtension: 'js'},
            'rxjs': {defaultExtension: 'js'}
        }
    });
    System.import('app/app');
</script>

Can somebody tell me what I'm doing incorrectly?

回答1:

Its definitly not needed to import all operators at once! You just imported fromEvent wrong. You could do it like this:

import {Observable} from 'rxjs/Observable';
import 'rxjs/add/observable/fromEvent';

EDIT: In addititon to what I already wrote: tree-shaking with the AoT-Compiler of angular removes unused code, based on what you import. If you just import some objects or functions from rxjs/rx, the compiler can't remove anything. Always import just, what you need!

回答2:

The problem seemed to be that the import statement should look like this:

import {Observable} from 'rxjs/Rx';

Note that Observable is being brought in from rxjs/Rx instead of from rxjs/Observable. As @EricMartinez mentions, pulling it in this way will automagically get you all of the operators (like .map()).