Updating the Blog App is usually a case of replacing the perch_blog folder in perch/addons/apps. See the Changelog for details of what has changed between the version you are updating from and the latest.

If you are updating from a version of Blog older than Blog 4.5 read the below important information.

Updating from a version prior to 4.5

With Blog 4.0, the post.html master template changed to more fully control the post editing process. Prior to this, more of the logic was hard-coded into the app itself.

If updating from an older version of Blog, you’ll need to make sure your post.html template has a full set of attributes for each tag. Check that:

Blog 4.5 introduced further changes to integrate the Categories functionality

Categories are now managed centrally. Your existing categories will be imported, but you need to add the following to your post.html template:

<perch:categories id="categories" set="blog" label="Categories" display-as="checkboxes">
  <a href="archive.php?cat=<perch:category id="catSlug" type="slug">">
    <perch:category id="catTitle" type="text">

As the categories system has been updated, you also need to update any blog templates that output categories:

  1. Convert the tags from <perch:blog> to <perch:category>
  2. Update the IDs from id="categoryX" to id="catX", e.g. categoryTitle to the new, shorter catTitle
  3. Update count tags from id="qty" to id="count.blog.post"

The easiest way to do this might be to take the new default templates and re-customize it to fit your site.