Preparation:

Have the class go to Administer >> Content >> Content types, and make the following changes to the "Story" content type:

• Workflow settings: Turn on revisions
• Comment settings: Change location of the comment form to below post/comments.

Take-aways:

hook_profile_alter():

• Mention how useful theme_image() is; it makes the image URL correct no matter whether you're in a subdirectory, have clean URLs, are using private files, etc.

hook_form_FORM_ID_alter():

• Emphasize that it's important to respect the existing validation functions. dsm() the $form array to show that there's an existing $form['#validate'] function. If you do:

  $form['#validate'] = array('mysite_user_register_validate');

  ...it will no longer check the username or email address for validity, and will let you pass through to submit, even if username is duplicate.

hook_views_data_alter():

• To do this one you actually have to have a view with a field that actually has the handler 'views_handler_field_numeric'. One is the comment count in the built-in tracker view.
• Also note that you actually have to go into the view and update the handler to "numerify". It doesn't just happen. You have to configure it.