Blogger JSON Feed API

Maybe sometimes we need a widget for certain features, but the widgets are not available. Blogger already provides an APIs to overcome this, so we can create our own widget by reading the blog feed using the JSON and JavaScript.

Here is the JSON feed API:

Here is an example implementation of the above code:

Suppose I need 5 recent posts by a certain label, the label I want to display is "Blogger". I took the title and summary of the post.

<script type="text/javascript">
  function mycallback(json) {
    for (var i = 0; i < json.feed.entry.length; i++) {
      for (var j = 0; j < json.feed.entry[i].link.length; j++) {
        if (json.feed.entry[i].link[j].rel == 'alternate') {
          var postUrl = json.feed.entry[i].link[j].href;
          break;
        }
      }
      var postTitle = json.feed.entry[i].title.$t;
      var postSummary = json.feed.entry[i].summary.$t;
      var item = '<div class="wrapper"><h3><a href=' + postUrl + '>' + postTitle + '</h3></a><p>' + postSummary + '</p></div>';
      document.write(item);
    }
  }
</script>
<script src="http://www.danpros.com/feeds/posts/summary/-/Blogger?max-results=5&alt=json-in-script&callback=mycallback"></script>

Note: we need to understand that json.feed.entry[i].summary.$t only available if we grab the feed URL using http://www.danpros.com/feeds/posts/summary instead of using http://www.danpros.com/feeds/posts/default.

Now how can we create a widget without unsorted recent post by a certain label? This widget also only displays 90 characters in the summary. The following is the example:

<script type="text/javascript">
  function mycallback(json) {
    for (var i = 0; i < json.feed.entry.length; i++) {
      for (var j = 0; j < json.feed.entry[i].link.length; j++) {
        if (json.feed.entry[i].link[j].rel == 'alternate') {
          var postUrl = json.feed.entry[i].link[j].href;
          break;
        }
      }
      var postTitle = json.feed.entry[i].title.$t;
      var postAuthor = json.feed.entry[i].author[0].name.$t;
      var postSummary = json.feed.entry[i].summary.$t;
      var entryShort = postSummary.substring(0, 90);
      var entryEnd = entryShort.lastIndexOf(" ");
      var postContent = entryShort.substring(0, entryEnd) + '...';
      var item = '<div class="wrapper"><h3><a href=' + postUrl + '>' + postTitle + '</h3></a><span>'+ postAuthor + '</span><p>' + postContent + '</p></div>';
      document.write(item);
    }
  }
</script>
<script src="http://www.danpros.com/feeds/posts/summary?orderby=published&max-results=5&alt=json-in-script&callback=mycallback"></script>