CODEWITHSUNDEEP
javascriptjqueryxmlsame-origin-policy
Muggy Ate
Muggy Ate

Reputation: 343

Requesting remote XML data with javascript

Ok here's my problem. I'm working on this little site called 10winstreak and I'm trying to detect if a stream is live or not with javascript because our server that we run the site off of cant handle processing every single request with PHP. The basis of detecting if a stream is live or not is you go to their XML file and in one of their tags (if it's live) it will say something along the lines of true and often time the XML file on their site will be empty if a particular stream isn't live. for example if you have a twitch.tv stream for gamespot you go to http://api.justin.tv/api/stream/list.xml?channel=gamespot and if it's got stuff in it then it's live if not then it's not.

so basically my code looks like this:

    function check (URL, term){
    $.get(URL , function(data){
        console.log(data);
        //data is whatever the server returns from the request, do whatever is needed with it to show who is live.

        var number = data.search(term);
        if (number > -1)            
        {
            document.write("Live");
        }

        else 
        {   
            document.write("Offline");
        }
    });
    }

and URL is a url that gets passed in and term is the term to search for in the xml file (usually "true" or "True"). but before anything happens I end up with "XMLHttpRequest cannot load http://api.own3d.tv/liveCheck.php?live_id=6815. Origin (my server's URL) is not allowed by Access-Control-Allow-Origin."

I've looked into it all over the net and i dont seem to be able to find anything that I can use. there's alot of theory stuff but not enough actual code and i dont understand the theory stuff to be able to start typing code out. from what i've seen you have 2 ways to go, use JSONP or add a line somewhere in your sever to allow for cross-domain accessing. neither of which i understand fully nor know how or what to do. It would be alot of help for someone to show me what needs to be done to get rid of this error. of course if you can explain it to a non-coder like me it would be even more awesome but at my current point, as long as the code works for all I care it might as well be magic lol.

Upvotes: 1

Views: 2429

Answers (4)

SD05
SD05

Reputation: 51

You can solve it :)

Take a look at xReader

<script src="http://kincrew.github.com/xReader/xReader.full.js"></script> 
<script type="text/javascript"> 
xReader("http://api.own3d.tv/liveCheck.php?live_id=6815", function(data) { 
    alert(data.content); 
})
</script>

I think you need cacheburst option. but you can be banned from YQL.

Upvotes: 1

machineghost
machineghost

Reputation: 35790

Short answer: unless 10winstreak offers a JSONP service, you'll have to do things on the server-side.

Slightly longer answer:

For security reasons browsers won't let you make AJAX requests from www.example.com to www.example2.com (or any other domain except www.example.com). There isn't much you can do about this except use JSONP (and you can only do that if the remote webservice offers it).

Therefore, what you end up needing to do is ask your server "hey what's on that other server?" and (since it's not limited the way a browser is) it can go get the XML from that other server. There are various ways of doing this, either with code or Apache config; not sure what's right for you, but hopefully now you understand the general principle.

P.S. See this question: Wouldn't have been simpler to just discard cookies for cross-domain XHR? if you are curious why browsers do this.

* EDIT *

I just checked out JustinTV's site, and it appears that they already have a PHP library for you to use: https://github.com/jtvapi/jtv_php_api

This is very likely your best bet (if you want to keep using PHP that is; if not they have libraries for other languages: http://www.justin.tv/p/api).

Upvotes: 0

JayC
JayC

Reputation: 7141

You aren't going to be able to do this via client-side javascript unless they've enabled some way to retrieve their data cross-domain (CORS, JSONP, some flash widgety thing getting read permissions from crossdomain.xml file(s) located on their server...)

Upvotes: 0

Parris
Parris

Reputation: 18408

I think its because the path is not relative. You may be calling this from a different domain/sub-domain. You can potentially allow other origins to access, which may open up a security hole or you can create a proxy locally.

In PHP creating a proxy is easy: http://blog.proxybonanza.com/programming/php-curl-with-proxy/ Now, instead of directing your request straight to that URL send the request from jQuery to your own local url and have it access it on the server side.

Another option would be to use YQL: http://www.parrisstudios.com/?p=333 (I wrote an article about this a while ago)... In that way you can turn the response into JSON, which can be accessed cross-domain (as can javascript).

You could ask for the API responses to all be returned using a JSONP server and in JSON.

Upvotes: 0

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