Dependency injection

[shashi]

We need to be able to load JavaScript files from Julia packages and the web, as and when required by components being displayed. Components provided by packages should be able to do this on their own. For example, if I'm using a PlotlyJS plot in my app, I should not worry about loading Plotly.js, PlotlyJS should ask WebIO to do that where it is invoked.

• Get /pkg/PKG/ to serve assets directory in Mux and Blink
• Create a Jupyter server plugin to allow serving asset files at /pkg/PKG
• decide AMD based dynamic loader script to use (options: LABjs, RaveJS, RequireJS)
• Make node creation asynchronous (promise-based or callback based)
• Create life cycle events during node creation on node dependency satisfaction, ready connection and creation completed.

[shashi]

I have mostly got this working. Will track the Jupyter requirement in #9

This is feeling pretty good. Check out the p5.js example: https://github.com/shashi/WebIO.jl/blob/master/examples/p5.jl which is a port of this https://p5js.org/examples/color-hue.html Guaranteed to have loaded p5js before rendering, and works on Atom, Blink and Mux 💃