If you install php extensions (https://savannah.nongnu.org/projects/php-ext-el/), you will have autocompletion and skeleton templates for many, many php functions:

$ cd ~
$ mkdir mydir
$ cd mydir
$ git clone git://git.savannah.nongnu.org/php-ext-el.git

Edit you .emacs and add:

(setq php-ext-path "~/mydir")
(load (concat php-ext-path "php-ext.el"))