Cannot access JSON text file stored in cache
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I'm having a little trouble with retrieving some JSON data from a field stored in my website's cache. The script I'm writing fetches the latest tweets from a twitter list, stores the JSON data it receives in a .txt file in the cache of the website. This is then read and turned into a string displaying the tweet, or at least it should. I have it working when I don't cache the tweets and just access them directly, but as soon as I try to cache the tweets then access them from cache I'm hitting a wall. The *cache-tweets.php* file is run as a cron job on the server, and works fine, it creates a text file that contains the JSON data no problems. The code for *cache-tweets.php* is below.

    $cache = dirname(__FILE__) . '/cache/twitter-json.txt';  
  
    $data = file_get_contents('https://api.twitter.com/1/lists/statuses.json?slug=tab&owner_screen_name=swoophoop&per_page=15&page=1&include_entities=true');   
  
    $cachefile = fopen($cache, 'wb');  
    fwrite($cachefile,utf8_encode($data));  
    fclose($cachefile);

This should then be used by this code:

    <script type ="text/javascript"> 
    $(document).ready(function(){
    $.ajax({
        dataType: 'json',
        url: 'htp://sotontab.co.uk/wp-content/cache/twitter-json.txt',
        success: function (data) {
        	var strTweet = '';
        	
            $.each(data, function(index, tweet){            	
				var user_link = '\x3Ca href="http://twitter.com/' + tweet.user.screen_name + '">' + '\x3Cb>' + tweet.user.name + '\x3C/b>\x3C/a>';
				strTweet=strTweet + user_link + ' : &nbsp' + tweet.text.linkify() + '&nbsp' + '\x3Cdiv class="time">' + relative_time(tweet.created_at) + '\x3C/div>&nbsp&nbsp&nbsp';
            });
            tweetMarquee = new Marquee($('div#marquee'),strTweet,$('div#marquee').width);
        }
    });
    });      
 
    
    </script>

If I replace the url in the above code with the url from *cahe-tweets.php* it works perfectly and the tweets display inside the marquee on my site. But if I run it as it is, nothing appears. The marquee doesn't even show up as empty. Does anyone know why it doesn't work with the site url as above? 