rwaldron/jsonp.html

## jsonp.html
<!DOCTYPE html>
<html>
<head>
  <script src="jsonp.js"></script>
  <script>
  document.addEventListener("DOMContentLoaded", function() {

    var requestUrl  = "http://en.wikipedia.org/w/api.php?action=parse&page=Dog&format=json";


    getJsonp({
      url: requestUrl,
      success: function( data ) {
        // `data` is the parsed JSON object
        console.log(data);
      }
    });

    getJsonp({
      url: requestUrl + "&callback=jsonpB",
      success: function( data ) {
        // `data` is the parsed JSON object
        console.log(data);
      }
    });


    getJsonp({
      url: requestUrl,
      jsonp: "jsonpC",
      success: function( data ) {
        // `data` is the parsed JSON object
        console.log(data);
      }
    });


  }, false);
  </script>
</head>
<body>
</body>
</html>

## jsonp.js
// forgive me, i've polluted.

function getJsonp( setup ) {

  var head = document.getElementsByTagName("head")[0] || document.documentElement,
    script = document.createElement("script"),
    rqstring = /\?/,
    rcall = /callback/,
    qstring = setup.url.split("?")[1],
    params;

  //  if the callback was specified in the url string
  if ( rcall.test( setup.url ) ) {

    //  break the query string
    params = qstring.split("&");

    //  the callback argument is expected to be the last key/val pair
    setup.jsonp = params[ params.length - 1 ].split("=")[1];
  }

  //  if no setup.jsonp, create a uniquely named callback
  setup.jsonp || ( setup.jsonp = "jsonp" + ( +new Date() ) );

  //  if no callback specified in url, add it
  if ( !rcall.test( setup.url ) ) {
    setup.url += ( rqstring.test( setup.url ) ? "&" : "?") + "callback=" + setup.jsonp;
  }

  //  set the script source
  script.src = setup.url;


  if ( setup.jsonp ) {
    //  define the jsonp setup.success callback globally
    window[ setup.jsonp ] = function ( data ) {
      setup.success( data );
      window[ setup.jsonp ].fired = true;
    };

    window[ setup.jsonp ].fired = false;
  }

  script.onload = script.onreadystatechange = function() {

    if ( window[ setup.jsonp ].fired ||
          ( this.readyState === "loaded" || this.readyState === "complete") ) {

      // cleanup in here
      delete window[ setup.jsonp ];
      head.removeChild( script );
    }
  };

  head.insertBefore( script, head.firstChild );
}
	<!DOCTYPE html>
	<html>
	<head>
	<script src="jsonp.js"></script>
	<script>
	document.addEventListener("DOMContentLoaded", function() {

	var requestUrl = "http://en.wikipedia.org/w/api.php?action=parse&page=Dog&format=json";


	getJsonp({
	url: requestUrl,
	success: function( data ) {
	// `data` is the parsed JSON object
	console.log(data);
	}
	});

	getJsonp({
	url: requestUrl + "&callback=jsonpB",
	success: function( data ) {
	// `data` is the parsed JSON object
	console.log(data);
	}
	});


	getJsonp({
	url: requestUrl,
	jsonp: "jsonpC",
	success: function( data ) {
	// `data` is the parsed JSON object
	console.log(data);
	}
	});


	}, false);
	</script>
	</head>
	<body>
	</body>
	</html>
	// forgive me, i've polluted.

	function getJsonp( setup ) {

	var head = document.getElementsByTagName("head")[0] \|\| document.documentElement,
	script = document.createElement("script"),
	rqstring = /\?/,
	rcall = /callback/,
	qstring = setup.url.split("?")[1],
	params;

	// if the callback was specified in the url string
	if ( rcall.test( setup.url ) ) {

	// break the query string
	params = qstring.split("&");

	// the callback argument is expected to be the last key/val pair
	setup.jsonp = params[ params.length - 1 ].split("=")[1];
	}

	// if no setup.jsonp, create a uniquely named callback
	setup.jsonp \|\| ( setup.jsonp = "jsonp" + ( +new Date() ) );

	// if no callback specified in url, add it
	if ( !rcall.test( setup.url ) ) {
	setup.url += ( rqstring.test( setup.url ) ? "&" : "?") + "callback=" + setup.jsonp;
	}

	// set the script source
	script.src = setup.url;


	if ( setup.jsonp ) {
	// define the jsonp setup.success callback globally
	window[ setup.jsonp ] = function ( data ) {
	setup.success( data );
	window[ setup.jsonp ].fired = true;
	};

	window[ setup.jsonp ].fired = false;
	}

	script.onload = script.onreadystatechange = function() {

	if ( window[ setup.jsonp ].fired \|\|
	( this.readyState === "loaded" \|\| this.readyState === "complete") ) {

	// cleanup in here
	delete window[ setup.jsonp ];
	head.removeChild( script );
	}
	};

	head.insertBefore( script, head.firstChild );
	}