With Blogger (FTP, Classic) how do you add features that are too complex for the template?

Using classic templates, publishing via FTP to a custom domain.

I want to add custom elements such as:

• a tree view for archived posts (expanding using CSS/JavaScript)
• a tag cloud
• a slideshow of images

From stackoverflow Liam

• I can't tell you the answer but you may be wise to research your question here.

  Liam : Thanks, but there was nothing relevant there.
  From Onorio Catenacci

• I used PHP to process a Blogger blog after it is published via FTP. Any server side language can do this (ASP, ASP.NET, Python, JSP, ...).

  I wrote a PHP script (blogger_functions.php) to scan the directory that Blogger FTP's to and generate a snippet of HTML to represent the archive hierarchy ($snippet).

  I added this PHP to the top of my Blogger template:

  <?php 
  
  <MainPage>
  $site_rootpath = "../";
  </MainPage>
  
  <ArchivePage>
  $site_rootpath = "../../";
  </ArchivePage>
  
  <ItemPage>
  $site_rootpath = "../../../";
  </ItemPage>
  
  include($site_rootpath."includes/blogger_functions.php");
  
  ?>
  

  And this to the sidebar part of the template:

  <?php
  echo $snippet;
  ?>
  

  Then I configured Apache to process the PHP tags in the blog's .html files by putting this in a .htaccess file in the root directory of the blog:

  AddType application/x-httpd-php .html .htm
  

  With this approach you can use the full power of PHP with a Blogger blog.

  From Liam

• So, do I add this as it is, or do I have to change anything? Where, specifically, do I add the code?

  Explain it to me like I'm an idiot. Thanks!

  From $pageUsers[$post.author].name