Allow globally loaded javascript libs

[filipesilva]

Some javascript libraries need to be loaded on the global scope, especially older ones. A great, common example is bootstrap, which needs jquery to be globally available.

Different build systems have different ways to allow this. Webpack has several alternatives to shimming modules, and so does SystemJS.

Angular-CLI needs to provide a way to load these files in order to provide interop with the simplest way of loading javascript files.

[iamyojimbo]

In case anyone really needs this NOW, in Webpack, the solution is to do:

window['jQuery'] = require('jquery')
window['Chart'] = require('chart.js')

I do this in my main.ts file because I assumed this needs to be done before the dependencies are loaded (as some of them have checks to see if jQuery is there before you even call a function).

I don't know if this works with SystemJS too.

[filipesilva]

@iamyojimbo very good advice, thank you!

[filipesilva]

#1747 adds instructions on how to use libs that need global scope using @iamyojimbo's technique.

It should be enough for now but if people start having more problems with libs, we can add more functionality to address global scripts.