Provides a JSONPRequest class for repeated JSONP calls, and a convenience method Y.jsonp(url, callback) to instantiate and send a JSONP request.

Both the constructor as well as the convenience function take two parameters: a url string and a callback.

The url provided must include the placeholder string "{callback}" which will be replaced by a dynamically generated routing function to pass the data to your callback function. An example url might look like "http://example.com/service?callback={callback}".

The second parameter can be a callback function that accepts the JSON payload as its argument, or a configuration object supporting the keys:

• on - map of callback subscribers
  • success - function handler for successful transmission
  • failure - function handler for failed transmission
  • timeout - function handler for transactions that timeout
• format - override function for inserting the proxy name in the url
• timeout - the number of milliseconds to wait before giving up
• context - becomes this in the callbacks
• args - array of subsequent parameters to pass to the callbacks
• allowCache - use the same proxy name for all requests? (boolean)