July 30, 2008

Emacs and PHP: There’s more than one way to do it, of course

July 30, 2008 - Categories: emacs

The PhpMode page on EmacsWiki lists five options for developing PHP in Emacs. I’m currently using the php-mode maintained by Aaron Hawley, and I’m quite happy with it. I’m curious about the php-mode maintained by Ahmet Usal, though, as it has extensive templating support and electric behavior. It seems to have abbreviations and argument lists for every PHP function, and I might borrow the code and convert it to a yasnippet file if I don’t end up using this. I’ll switch to Ahmet Usal’s php-mode today, see what it feels like, and post my notes. Has anyone else tried both?

Emacs and PHP tutorial: php-mode

July 30, 2008 - Categories: emacs, wickedcoolemacs

php-mode is responsible for syntax highlighting, indentation, and other major PHP-specific modifications to your editing environment. There are a number of PHP modes available for Emacs. In this project, you’ll learn how to set up the php-mode available from http://sourceforge.net/projects/php-mode/ . At the time of this writing, the current version is 1.4.0 and the maintainer is Aaron Hawley.

Download the latest php-mode.el from http://php-mode.sourceforge.net/ and save it to a directory in your load-path. I like to organize my Emacs Lisp files in a directory called ~/elisp. To add PHP support to your Emacs, add the following lines to your ~/.emacs:

 (add-to-list 'load-path "~/elisp")
 (require 'php-mode)

This configures Emacs to automatically recognize files ending in “.php”, “.phps”, “.php3″, “.php4″, “.phtml”, and “.inc” as PHP files. To associate more extensions with PHP files, add lines like this example to your ~/.emacs:

 (add-to-list 'auto-mode-alist '("\\.module$" . php-mode))
 (add-to-list 'auto-mode-alist '("\\.inc$" . php-mode))
 (add-to-list 'auto-mode-alist '("\\.install$" . php-mode))
 (add-to-list 'auto-mode-alist '("\\.engine$" . php-mode))

This associates php-mode with the extensions used by Drupal, a PHP framework. When you open a file with the specified extension, it should be highlighted according to PHP syntax.

Here are some useful commands:

TAB c-indent-command Indent the current line
M-; comment-dwim Add a line comment, comments or uncomments the currently-selected region, or does other smart comment-related actions
C-c C-f php-search-documentation Search the online PHP manual for the current word
C-c RET php-browse-manual View the online PHP manual
C-c . c-set-style Change coding style
C-M-a, C-M-e c-beginning-of-defun, c-end-of-defun Go to the beginning or end of the current function
C-M-h c-mark-function Select the current function
M-a, M-e c-beginning-of-statement, c-end-of-statement Go to the beginning or end of the current statement

Here are some variables you may wish to customize:

indent-tabs-mode Set this to nil if you want to insert spaces instead of tabs
case-fold-search Set this to t if you want case-insensitive search.
c-basic-offset Set your tab size or number of spaces used as a basis for indentation

You can either customize these variables globally with M-x customize or set them for php-mode. Here’s an example that sets up a buffer with the coding style recommended for Drupal:

 (defun wicked/php-mode-init ()
   "Set some buffer-local variables."
   (setq case-fold-search t) 
   (setq indent-tabs-mode nil)
   (setq fill-column 78)
   (setq c-basic-offset 2)
   (c-set-offset 'arglist-cont 0)
   (c-set-offset 'arglist-intro '+)
   (c-set-offset 'case-label 2)
   (c-set-offset 'arglist-close 0))
 (add-hook 'php-mode-hook 'wicked/php-mode-init)

You can further customize the indentation by moving the point to where the indentation needs improvement and typing C-c C-o (c-set-offset).

To try automatic indentation, press C-j (newline-and-indent). If you like that behavior, you can make it the default in php-mode by adding the following line in ~/.emacs:

(define-key php-mode-map (kbd “RET”) ‘newline-and-indent)

You may also be interested in M-x show-paren-mode, which shows the matching parenthesis, bracket or brace for the character at point. You can enable it automatically by adding the following line to your ~/.emacs:

   (setq show-paren-mode t)

It’s a good idea to separate PHP and HTML code. This is not only better coding practice, but it also makes developing in Emacs much easier. php-mode focuses on PHP-specific behavior and does not have special support for HTML. Emacs has a number of packages that allow you to work with multiple modes like php-mode and html-helper-mode in a single buffer, but they don’t always work, and indentation can be confusing. If you must work with large segments of both PHP and HTML in the same file, check out MultipleModes (http://www.emacswiki.org/cgi-bin/wiki/MultipleModes) for tips.