How to make a JSON call to an URL?

I'm looking at the following API:

http://wiki.github.com/soundcloud/api/oembed-api

The example they give is

Call:

http://soundcloud.com/oembed?url=http%3A//soundcloud.com/forss/flickermood&format=json

Response:

{
"html":"<object height=\"81\" ... ",
"user":"Forss",
"permalink":"http:\/\/soundcloud.com\/forss\/flickermood",
"title":"Flickermood",
"type":"rich",
"provider_url":"http:\/\/soundcloud.com",
"description":"From the Soulhack album...",
"version":1.0,
"user_permalink_url":"http:\/\/soundcloud.com\/forss",
"height":81,
"provider_name":"Soundcloud",
"width":0
}

What do I have to do to get this JSON object from just an URL?

Solution 1:

A standard http GET request should do it. Then you can use JSON.parse() to make it into a json object.

function Get(yourUrl){
    var Httpreq = new XMLHttpRequest(); // a new request
    Httpreq.open("GET",yourUrl,false);
    Httpreq.send(null);
    return Httpreq.responseText;          
}

then

var json_obj = JSON.parse(Get(yourUrl));
console.log("this is the author name: "+json_obj.author_name);

that's basically it

Solution 2:

It seems they offer a js option for the format parameter, which will return JSONP. You can retrieve JSONP like so:

function getJSONP(url, success) {

    var ud = '_' + +new Date,
        script = document.createElement('script'),
        head = document.getElementsByTagName('head')[0] 
               || document.documentElement;

    window[ud] = function(data) {
        head.removeChild(script);
        success && success(data);
    };

    script.src = url.replace('callback=?', 'callback=' + ud);
    head.appendChild(script);

}

getJSONP('http://soundcloud.com/oembed?url=http%3A//soundcloud.com/forss/flickermood&format=js&callback=?', function(data){
    console.log(data);
});