神秘的ajax json请求问题jQuery

Question

I want to read an rss feed converted to json format with a google api ; i had put some alerts but i can't see them when i run my page ! Why ?

Here is my jQuery code :

function getFeed(url){
        $('#screen #content').html("");
        $.ajax({
            url: 'https://ajax.googleapis.com/ajax/services/feed/load?v=1.0&q='+url,
            crossDomain: true,
            dataType: 'json',
            success: function(data) {
                alert(3);
                $.each(data.entries, function(i,results){
                    alert(1);

                });
            }
        });
    }
    getFeed('http://www.nytimes.com/services/xml/rss/nyt/Science.xml');

Thanks !

Answer 1

Ajax requests are limited by the browser's Same Origin Policy. You can't talk directly to a server via ajax that isn't on the same domain as the page your script is running in. So, you need to use the jsonp feature from jquery ajax:

$(document).ready(function () {

        function getFeed(url) {
            $.ajax({
                url: 'https://ajax.googleapis.com/ajax/services/feed/load?v=1.0&q=' + url,
                crossDomain: true,
                dataType: 'jsonp',
                success: function (data) {
                    console.log(data);

                },
                error: function (data) {
                    console.log(data);
                }
            });
        }
        getFeed('http://www.nytimes.com/services/xml/rss/nyt/Science.xml');

    });

dataType: 'jsonp' is the keyword here.

You can read more about it searching 'jsonp' here: http://api.jquery.com/jQuery.ajax/

or here: http://bob.ippoli.to/archives/2005/12/05/remote-json-jsonp/

Answer 2

1. It can also be possible that the host you are requesting to, doesn't allow third-party or cross-browser ajax calls.
2. If you are expecting JSON as in result from request, use $.getJSON() .

Thanks Rahul