UMD support

[zewa666]

Adds UMD support for the libraries build artifacts

Related issue: https://github.com/chartjs/chartjs-plugin-deferred/issues/2

[zewa666]

As explained in the referenced issue I wouldn't see any easy way, for any module bundler to take full control, over when dependencies are properly timed. So an UMD approach seems to be the best to satisfy a broad variety of module formats.

Please do make sure this change doesn't break any pre-existing use cases, I didn't really find anything special but it would make sense to take some existing examples and properly check those.

I've also seen that you leverage gulptasks, so I felt free to modify those, but you might wanna think about creating a 3rd build articaft containing the umd exports

[zewa666]

Alright I've added the requested changes. One tip. How about rewriting the gulpfile to ES6 so it could be removed from the eslintignore list?

[simonbrunel]

Looks good, thank, will try to test that very soon! The gulpfile is in the eslintignore because it doesn't use the same indentation rules as the plugin. Though, I already have some changes locally and can have a look to migrate to ES6.

That could be interesting to look at the other Chart.js hosted plugins to make them fully compatible with other environments such as Aurelia ;)

[zewa666]

@simonbrunel wonder why my local eslint didn't capture that ... strange. Good catch thanks

[simonbrunel]

gulp-umd uses the filename (capitalized) as the global namespace and so tries to set window.Plugin = Plugin, which doesn't look nice. Also, the plugin doesn't export anything and module.exports = undefined doesn't look good either.

It's possible to configure the target namespace but since gulp-umd doesn't do a lot and seems not anymore maintained, I think it's easier to directly implement UMD inside plugin.js:

'use strict';

;(function(root, factory) {
    if (typeof define === 'function' && define.amd) {
        define(['chart.js'], factory);
    } else if (typeof exports === 'object') {
        module.exports = factory(require('chart.js'));
    } else {
        factory(root.Chart);
    }
}(this, function(Chart) {
    var helpers = Chart.helpers;

        // ...

    var plugin = {
        beforeInit: function(instance) {
        // ...
    };

    Chart.plugins.register(plugin);
    return plugin;
}));

@zewa666 what do you think?

[zewa666]

Fewer dependencies is always better. I was just unsure whether you'd like to have it as part of your gulp build, but if you're fine with placing it in plugin.js it's definitely fine as well

[simonbrunel]

@zewa666 I'm fine with having it in plugin.js, do you want to update that PR or should I implement it in my upcoming changes?

[zewa666]

hey @simonbrunel, yeah if you don't mind that would be easier. I'll close this PR thanks for the reviews. 👍

[simonbrunel]

Thanks for your help and time :)

[simonbrunel]

After investigating a bit more, I think I will use rollup which generates a better UMD code than gulp-umd.

[zewa666]

Sure, which also has a lot of traction these days. Good choice