Using YouTube API to get all comments from a video with the JSON feed

javascript, json, youtube, youtube-api

Solution

I just came across this question and I notice that its been quite some time when this was asked. But since nobody answered it yet, I think I should do that.

What you should ideally do is, use Youtube's PHP API (using Zend_GData) and use the following code in PHP:

<?php

    require_once 'Zend/Loader.php'; // the Zend dir must be in your include_path
Zend_Loader::loadClass('Zend_Gdata_YouTube');

$yt = new Zend_Gdata_YouTube();
$yt->setMajorProtocolVersion(2);
$video = parse_url("http://www.youtube.com/watch?v=K-ob8sr9ZX0");
parse_str(urldecode($video['query']), $query);
$videoId = $query['v'];

$commentFeed = $yt->retrieveAllEntriesForFeed($yt->getVideoCommentFeed($videoId));

foreach ($commentFeed as $commentEntry) {
    echo "Full text: " . $commentEntry->content->text . "<br />";
}

The key element here is the retrieveAllEntriesForFeed() method.

Instead of echo-ing all the comments, you can construct a JSON and send it back to the waiting Javascript.

It does not use the max-results or start-index, but does the job well without them.

Problem

I'm using the YouTube API to get comments for a video with a parameterized query like the following: `http://gdata.youtube.com/feeds/api/videos/theVideoID/comments?v=2&alt=json` The problem with this is that the maximum number of results you can get per query is 50. I want to get every comment. I'm currently using the `start-index` and `max-results` parameters to solve this. I had a bit of trouble doing iterations of 50 at a time because sometimes the iteration would have a start-index above the number of comments and I couldn't figure that out, so I just tried to work out one at a time. It may be better to do 50 at a time, so let me know if that is the better solution. For now: I'm using PHP to get the amount of comments: ``` <?php $video_ID = 'gT2HYxOdxUk'; $JSON = file_get_contents("https://gdata.youtube.com/feeds/api/videos/{$video_ID}?v=2&alt=json"); $JSON_Data = json_decode($JSON); $commentCount = $JSON_Data->{'entry'}->{'gd$comments'}->{'gd$feedLink'}->{'countHint'}; ?> ``` And then I'm calling a JavaScript/jQuery function to load all comments into an array. For testing, it prints them into a div. For starters, here's how I'm calling the function: ``` <body onLoad="loadComments('<?php echo $commentCount; ?>', '<?php echo $video_ID; ?>')"> ``` Next, the actual function: ``` function loadComments(count, videoID) { for(i = 1; i <= count; i++) { $.ajax({ url: "http://gdata.youtube.com/feeds/api/videos/" + videoID + "/comments?v=2&alt=json&max-results=1" + "&start-index=" + i, dataType: "jsonp", success: function(data){ $.each(data.feed.entry, function(key, val) { comments.push(val.content.$t); $('#commentOutput').append(val.content.$t + '<br>'); //Just for testing purposes. }); } }); } } ``` The problem is that it is really iffy. When I use the `count` variable as the terminating part of the for loop like this, it always gets like, for example, 45 out of 211 comments. If I manually enter 211, it will go to around 195. If I put in a low number, like 1-15, it pretty much always gets them all. 20+, it's never right. I need to figure out how to get this to consistently get all the comments of a given video by taking advantage of the `max-results` and `start-index` parameters. Thanks!

Original source