JSONp using closure

gistfile1.js

var jsonp = {
	callbackCounter: 0,

	fetch: function(url, callback) {
		var fn = 'JSONPCallback_' + this.callbackCounter++;
		window[fn] = this.evalJSONP(callback);
		url = url.replace('=JSONPCallback', '=' + fn);

		var scriptTag = document.createElement('SCRIPT');
		scriptTag.src = url;
		document.getElementsByTagName('HEAD')[0].appendChild(scriptTag);
	},

	evalJSONP: function(callback) {
                // eval이 아닌 JSON object 를 사용하도록 조치하기 위한 closure 도입.
		return function(data) {
			var validJSON = false;
			if (typeof data == "string") {
				try {
					validJSON = JSON.parse(data);
				} catch (e) {
					/*invalid JSON*/
				}
			} else {
				validJSON = JSON.parse(JSON.stringify(data));
				window.console && console.warn('not valid JSON string');
			}

			if (validJSON) {
				callback(validJSON);
			} else {
				throw("not valid json");
			}
		};
	}
}

// 사용예제
/*
var obamaTweets = "http://www.twitter.com/status/user_timeline/BARACKOBAMA.json?count=5&callback=JSONPCallback";
jsonp.fetch(obamaTweets, function(data) {console.log(data[0].text)});

var reddits = "http://www.reddit.com/.json?limit=1&jsonp=JSONPCallback";
jsonp.fetch(reddits , function(data) {console.log(data.data.children[0].data.title)});
*/

Any concern about leaking memory if you do many JSONP requests on one page? There is no cleanup of your JSONPCallback_ methods.

oh. thanks. miss that

Thanks for this!