Creates a JSON request using script tag injection and handles the callbacks for you.

• Online Tutorial/Demo

• Options, Events

new Request.JSONP(options);

1. options - (object) an object with key/value options

• url - (url) the url to get the JSON data
• callbackKey - (string: defaults to callback) the key in the url that the server uses to wrap the JSON results. So, for example, if you used callbackKey: 'callback' then the server is expecting something like http://..../?q=search+term&callback=myFunction; This must be defined correctly.
• data - (string: defaults to '') The default data for Request-JSONP:send, used when no data is given.
• link - (string: defaults to 'ignore') Can be 'ignore', 'cancel' and 'chain'.
  • 'ignore' - Any calls made to start while the request is running will be ignored.
  • 'cancel' - Any calls made to start while the request is running will take precedence over the currently running request. The new request will start immediately, canceling the one that is currently running.
  • 'chain' - Any calls made to start while the request is running will be chained up, and will take place as soon as the current request has finished, one after another.
• timeout - (number: defaults to 0) In conjunction with onTimeout event, it determines the amount of milliseconds before considering a connection timed out. (It's suggested to not use timeout with big files and only when knowing what's expected.)
• injectScript - (mixed: defaults to document head) where to inject the script elements used for the calls
• log - (boolean: defaults to false) if true, sends logging messages with console.log as default onRequest and onError events.

• onRequest - (function, optional) fired when the script tag is injected; it will pass the requested url and the script element.
• onComplete - (function, optional) fired when the data returns; it will be passed the data and the instance of Request.JSONP that requested it.
• onCancel - (function, optional) fired when the request is canceled.
• onTimeout - (function, optional) fired when the timeout has been exceeded.

var myJSONP = new Request.JSONP({
    url: 'http://www.flickr.com/services/feeds/photos_public.gne?format=json',
    callbackKey: 'jsoncallback',
    data: {
        partTag: 'mtvo',
        iod: 'hlPrice',
        viewType: 'json',
        results: '100',
        query: 'ipod'
    },
    onRequest: function(url){
        // a script tag is created with a src attribute equal to url
    },
    onComplete: function(data){
        // the request was completed.
    }
}).send();

The above example would generate this url:

http://www.flickr.com/services/feeds/photos_public.gne?format=json&jsoncallback=Request.JSONP.request_map.request_0

It would embed a script tag (in the head of the document) with this url and, when it loaded, execute the "myFunction" callback defined.

Executes the JSON request.

myJSONP.send([options]);

1. options - (object; optional) key/value options that configure the request. Can either be the same as (or a subset of) the options for the class, an element (such as a form) whose child inputs will be converted into a query string, or a query string.

• (object) This instance of Request.JSONP

Cancels the currently running request, if any.

myJSONP.cancel();

• (object) This instance of Request.JSONP

Returns true if the request is currently running

myRequest.isRunning()

• (boolean) True if the request is running

if (myJSONP.isRunning()) // It runs!