Drupal, Emacs, and templates: Module update functions

Drupal’s coding conventions make it easier to hook into system behavior, but they also result in a lot of repetitive typing. For example, you can run code when upgrading a module by putting the code in a function named modulename_update_N() in your module’s install file. I found myself scrolling up and copy-pasting stuff too many times, so I decided to automate it instead.

I’ve been using yasnippet for my Emacs templates. All I needed to do to automate that little update bit was to write some code that figured out what the next update number should be. Here’s the snippet file I’ve just added (~/elisp/snippets/php-mode/drupal-mode/_update):

function `(sacha/drupal-module-name)`_update_`(sacha/drupal-module-update-number)`() {
  $ret = array();
  $0
  $ret[] = array(
    'success' => true,
    'query' => '$1',
  );
  return $ret;
}

The relevant functions from my ~/.emacs:

(defun sacha/drupal-module-update-number ()
  "Return the number of the next module update function.
This is one more than the highest number used so far.
This function should be called in a module's .install file."
  (save-excursion
    (save-restriction
      (widen)
      (goto-char (point-min))
      (let ((module-name (sacha/drupal-module-name))
	    (max 0))
	(while (re-search-forward
		(concat "function[ \t\n]+" module-name "_update_\\([0-9]+\\)") nil t)
	  (setq max (max (string-to-number (match-string 1)) max)))
	(number-to-string (1+ max))))))

(defun sacha/drupal-module-name ()
  "Return the Drupal module name for .module and .install files."
  (file-name-sans-extension (file-name-nondirectory (buffer-file-name))))

I can’t think of how I’d do that in Eclipse. =) Don’t get me wrong–I still like Eclipse–but I heart being able to hack my editor on the fly.