Restore the JS Spinning Cube demo

examples/js/README.md

 JavaScript Mojo Example Applications
 =====================
 
 hello.js, world.js - A minimal application that connects to another.
 
 wget.js - Uses the network service to load a URL.
 
+cube.js - A JS version of examples/sample_app.

[Aaron Boodman, 2014/12/09 20:24:53]

cool :)

 
 --- Running Mojo Applications --- 
 
 A Mojo application written in JavaScript is launched with mojo_shell like this:
 
   mojo_shell <js-application-url>
 
 Where js-application-url is either a file or an http URL that names a JS source

[Aaron Boodman, 2014/12/09 20:24:53]

Nit: it can be any URL that mojo shell understands, which is at least mojo,
http[s], and file. Maybe data URLs work too !?. Not sure about wget :). ... also
this list will probably expand over time. Maybe should just say "URL" and leave
it vague.

[hansmuller, 2014/12/09 20:43:21]

I left the bit about using a file or http URL in as a "for example" and changed
the initial sentence to say "... us a URL understood by the shell".

 file. The JS file itself must begin with a Mojo "shebang" that specifies the
 Mojo URL of the JS content handler. In other words, the first line of the JS
 source file must be:
 
   #!mojo:js_content_handler
 
 Following the shebang should be a single AMD module called "main" whose value
 is an Application subclass. The JS content handler will create an instance of
 the Application and make it the client of the Mojo shell. The JS content handler
 is itself a Mojo application and it's responsible for creating an instance of V8
@@ skipping 162 matching lines @@
 response parameter. In the EchoString case that would be something like 
 {value: "foo"}.
 
 Similarly, the implementation of a Mojo interface functions that specify a
 response, must return a Promise. The implementation of EchoString() could
 be written like this:
 
   MyEchoStringImpl.prototype.EchoString = function(s) {
     return Promise.resolve({value: s});
   };