Need to reduce library size

[etimberg]

With the addition of horizontal bars, v2 is huge! We need to refactor code to improve minification. I think we can shave off 20KB or more from the minified size

Largest individual source files

Minified size determined using: http://jscompress.com

Listed in decreasing order of minfied size

File	Starting Unminified Size	Starting Minified Size	Current Minified Size
Core.helpers.js	28.2 KB	13.18 KB
Core.scale.js	24.1 KB	12.46 KB
Core.tooltip.js	19.2 KB	10.77 KB
Core.controller.js	18.0 KB	9.74 KB
Scale.radialLinear.js	16.7 KB	7.02 KB
Controller.line.js	12.1 KB	7.69 KB
Controller.doughnut.js	11.9 KB	7.32 KB	5.33 KB
Scale.time.js	13.1 KB	6.92 KB
Controller.radar.js	9.6 KB	6.49 KB
Controller.polarArea.js	9.5 KB	6.36 KB	4.24 KB
Controller.bar.js	10.7 KB	6.10 KB
Core.legend.js	10.1 KB	5.13 KB
Controller.bubble.js	6.6 KB	4.24 KB
Scale.linear.js	8.9 KB	4.02 KB	3.65 KB
Scale.logarithmic.js	6.1 KB	2.98 KB	2.88 KB
Core.title.js	5.0 KB	2.73 KB	2.16 KB
Element.line.js	5.1 KB	2.58 KB
Element.point.js	4.4 KB	2.58 KB	2.45 KB
Core.layoutService.js	10.6 KB	2.42 KB
Core.animation.js	4.0 KB	2.28 KB
Core.js	3.3 KB	1.66 KB

Other dependencies

File	UnminifiedSize	Minified Size
Color.min.js	114 KB	22.8 KB

[etimberg]

@tannerlinsley @derekperkins @zachpanz88 can you help expand the table at the top?

From the Chart.js folder, the following will find all src files and order them by size from largest to smallest.

find ./src -type f -printf "%s\t%p\n" | sort -n

[panzarino]

I added all of the biggest files. I left out smaller files because their size was so small that any reduction would not be significant to the overall build.

[etimberg]

Thanks @zachpanz88

[panzarino]

I think we should increase the docs about creating custom builds (is this still supported in v2?), which would allow users to create their own file with only the charts they need. This is all I found (v1.1.1).

If it is no longer supported, adding it back could be a good option to reduce file size.

[etimberg]

Yeah, we can add it back. Certainly stuff like the controllers and scales can be dropped without too much work

[hbrls]

+1 and that's why I'm still with v1

[etimberg]

Made some progress on the doughnut / polar area controllers. I actually think the polar area controller could derive from the doughnut controller because they are almost identical

[panzarino]

I'm thinking that we should revisit the idea of making the library smaller. I will work on setting up a build system where users can choose what types of charts/scales they want to use without having to use the entire library.

[simonbrunel]

@zachpanz88 I don't think that's the solution because it seems that most users just want to use dist/* files (CDN/NPM/Bower) and don't want to build a custom version on their own. We can't generate all possible combinations (currently 5020?) of chart/scale types, so finally, changing the build process might be overkill since it will satisfy only a few users (in addition to become tricky and maybe confusing).

Instead, I really think we should focus our effort on making plugins famous and easy to use: plugins should be accessible via a dedicated web page with proper descriptions, links, live examples and documentation - for all existing plugins - but also packag-able online (e.g. Zepto Builder or Prism). We could also provide an endpoint to dynamically generate a custom package (e.g. http://download.chartjs.org/?plugins=bar-chart,line-chart,linear-scale,time-scale,zoom,deferred). It should be also easy to use plugins with NPM/Bower (maybe via a centralized in a repository via submodules).

There is a lot to do around plugins, not only in the code, surely not exactly this way, so would require a deeper brainstorm from all of us. But as soon as we can really rely on plugins, we could move charts/scales as plugins (in their own repositories), and keep the "core" pretty small. Of course that's a pretty huge / complex task, but I feel it's more the direction to go to make the library smaller with a robust build process. It would also encourage people to use plugins and/or create and distribute their own without pushing to make that part of the "core" - and so less GH issues :).