What about something like this – issues the request along with a timeout that cancels the request if the callback isn’t invoked after a certain period (10 secs in this example). Not tested but you get the idea:

var requestManager={
timeout:10,
complete:[],
add:function(url, callback, onError){
var timer;
var func=function(json){
clearTimeout(timer);
callback(json);
};
var id=this.complete.push(func)-1;
timer=setTimeout(function(){
requestManager.complete[id]=function(){};
if (onError) onError();
}, requestManager.timeout*1000);

requestManager.add("http://json.com?a=b", function(json){
// got me some JSON
},function(){
// timed out or otherwise failed
});

@blinkingmarquee, No need to use strict comparison with typeof. The typeof operator always returns a string. So something like typeof “abc” == “string” is sufficient.

to Darkimmortal — good rundown.

That being said, it doesn’t do anything of course to address the single biggest problem with JSON-P, and that’s not knowing if a response timed out or otherwise failed. I.e., make a request that you get a 404 or 500 for and you never know it. If someone has a clever way of dealing with that I would absolutely LOVE to hear it :)

- – -

DarkImmortal,

Yes, sometimes the best programming practices means omitting some standard syntax possibilities. While leaving out the curly braces from conditionals works it encourages coding errors. The way it’s formatted in the example, it’s easy to miss the if statement entirely. With other formatting, it could be easy to not see what is affected by the if statement, to accidentally change what is affected by the if statement, or to mistakenly add code that looks like it should be affected by the if statement but is not.

Use curly braces. It’s only a difference of 0.002 KiB, greatly enhances readability, and could be programatically stripped for output if you really need to recover every byte possible.

and frown upon omitting the {} of the if statement

You frown upon using standard syntax? :/

callback && callback({...});

throw new Error(‘Callback method is undefined or a not a function’);

I don’t think Bing should be second-guessing API users by placing any checks before the data. Can I just have the data!??