Ajax not calling callback function

Question

I am trying to get a JSON object from a service running on port 8080 on my server. I have implemented the following JavaScript and PHP code to achieve this:

JavaScript:

$.ajax({
    type: 'GET',
    url: "mediainfo.php?file="+stream_,
    dataType: 'json',
    success: play,
    error: function( xhr, reply ) {
       play({});
    }
});

mediainfo.php:

<?php
    $url = "http://localhost:8080/media_info/" . $_GET['file'];
    echo file_get_contents($url);

However even if the Ajax call succeeds it never calls the callback. Strangely if it fails (e.g. if $url does not return valid JSON) it does call the callback.

I can't figure out what's going wrong. Any help would be much appreciated.

edit:

callback function:

var play = function( info ) {
     if ( info.width && info.height ) {
         while ( info.width < 640 ) {
             info.width = Math.round( info.width * 1.5 );
             info.height = Math.round( info.height * 1.5 );
         }
         while( info.width > 1024 ) {
             info.width = Math.round( info.width / 2 );
             info.height = Math.round( info.height / 2 );
         }
     }

     var width = info && info.width || 640;
     var height = info && info.height || 480;
     var flashvars = {
         file : stream,
         streamer : "rtmp://myserver.com:1935/vodplayback",
         'rtmp.tunneling' : false,
         bufferlength : 5,
         autostart : true
     };
     var paramObj = {allowfullscreen : "true", allowscriptaccess : "always"};
     swfobject.embedSWF("http://myserver.com:8080/flu/jwplayer.swf", "videoplayer", width, height, "10.3", false, flashvars, paramObj, {id : "jwplayer", name : "jwplayer"});
  }

response from mediinfo.php:

{"duration":69960.0,"width":720,"height":406}

Your PHP code seems to present a vulnerability. Imagine if I try to access to mediainfo.php?file=../private/file_i_should_not_see. — Pik'
– Pik', Commented Aug 9, 2013 at 1:47
@Pikrass Thanks for the response. The PHP code will only respond with basic info about a media file. Do you think this still presents a vulnerability? — mfa
– mfa, Commented Aug 9, 2013 at 2:04

mfa · Accepted Answer · 2013-08-09 02:38:39Z

1

So it turns out that the order of function declarations matter with Ajax calls. Who knew ^^

I had my callback function defined after the Ajax call. I switched them round and now it works fine.

Thanks for the responses.

edited Aug 9, 2013 at 2:38

answered Aug 9, 2013 at 2:26

mfa

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1 Comment

brenjt Over a year ago

If your play function was written like so: function play(){...} rather than using var play = function... Your problem wouldn't have existed. One of the weird things about javascript.

Yuan Zhaohao · Accepted Answer · 2013-08-09 01:57:43Z

0

$.ajax({
    url: 'test.php',
    dataType: 'html',
    data: { test: 'test' },
    type: 'GET',
    success: function( data ) {
        console.log( 'success' );
        $( '#div2' ).html( data );
    },
    error: function( xhr ) {
        console.log( xhr.status );
    }

});

or like this

<?php
$url = "http://localhost:8080/media_info/" . $_GET['file'];
echo json_encode( Array(
    'data': file_get_contents( $url )
) );
?>

javascript

$.ajax({
    url: 'test.php',
    dataType: 'json',
    data: { file: stream_ },
    type: 'GET',
    success: function( callback) {
        console.log( 'success' );
        $( '#div2' ).html( callback.data );
    },
    error: function( xhr ) {
        console.log( xhr.status );
    }

});

answered Aug 9, 2013 at 1:57

Yuan Zhaohao

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1 Comment

David-SkyMesh Over a year ago

This doesn't answer the question ("why isn't the success callback being called?"). You've proposed methods for in-code debugging, but haven't explained it to the OP.

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