Import UMD Javascript Modules into Browser

问题

Hi I am doing some research on RxJS. I am able to use the library simply by referencing it in my browser as such:

<script src="https://unpkg.com/@reactivex/rxjs@5.5.6/dist/global/Rx.js"></script>

It imports with the global object namespace variable of 'Rx'. I can make observables and do all the fun stuff.

Where everything breaks down is when I change the src to point to the latest UMD file like this <script src="https://unpkg.com/rxjs/bundles/rxjs.umd.js"></script>

The import seems to not be working as exported object functions don't seem to exist?

There is a specific function I am trying to use called 'fromEvent' that allows an observable to be created from any DOM event.

I am getting an error when using the latest RxJS 6.2.2 UMD file.

Why is this? If you look inside the js file at the bottom you can see the export of the function and at the top of the file you see the global namespace called 'rxjs'.

I am not using any loaders like requirejs nor do I have any experimental browser features enabled. I am not using any 'import' statements.

I am simply trying to reference the global namespace of the script object. The syntax for the module definition is identical except for Rx vs rxjs.

To replicate the error, simply create an Observable.fromEvent(.... and watch the error console.

Thanks!

回答1:

1. Recently the UMD bundle was renamed to just rxjs, see https://github.com/ReactiveX/rxjs/commit/556c904ea61a8424e5d24f170b20eadbc05d01f0#diff-6d2911fe563068b8126098588db98a84

2. If you want to use RxJS 6 you need to switch to "pipable" operators (and creation functions), see https://github.com/ReactiveX/rxjs/blob/master/docs_app/content/guide/v6/migration.md#operator-pipe-syntax

So for example this works:

<script src="https://unpkg.com/rxjs/bundles/rxjs.umd.js"></script>
<script>
rxjs.fromEvent(document, 'click').subscribe(console.log);
</script>

Demo: https://stackblitz.com/edit/rxjs6-demo-r2rtbz?file=index.html

回答2:

Here is an example after doing the proper import , note the pipe.

submission = rxjs.fromEvent($('#mybutton'), 'click')
    .pipe(rxjs.operators.map((event) => {
        return "something"
    }));

I may rename the globals to 'r' and 'ro' to avoid the new verbosity.

Also bonus points if someone can point to piped error handling in 6.0!

回答3:

It imports with the global object namespace variable of 'Rx'.

Maybe version 5.5.6 does but the latest version which you're trying to use, 6.2.2, does not. The object it exports to the global namespace is called rxjs. If you load https://unpkg.com/rxjs/bundles/rxjs.umd.js in a browser you'll see this in the source in the UMD module definition:

(function (global, factory) {
    typeof exports === 'object' && typeof module !== 'undefined' ?                             factory(exports) :
    typeof define === 'function' && define.amd ? define(['exports'], factory):
    (factory((global.rxjs = global.rxjs || {})));
}(this, (function (exports) { 'use strict'; // etc

If you want to use fromEvent you can do so via rxjs.fromEvent.

来源：https://stackoverflow.com/questions/51461723/import-umd-javascript-modules-into-browser