Highlight some specific text in Emacs

Question

I am using web-mode for my php files: http://web-mode.org/

And I call often a php function which looks like this:

__lg('Some text here', 'Global', NULL, FALSE);

This function can be call with only one argument like:

__lg('Hello world');

Is it possible to automaticly highlight the text between the 2 single quotes of the first argument of my function __lg() ?

I would like it to be colored in #ff007c for exemple.

I think I would have to modify the library web-mode.el that I use ?

Answer 1

You do not need to modify web-mode.el. You just add a new font-lock keyword in web-mode-hook. The code below demonstrates that. You can store it in your init file.

(defface my-web-mode-hl__lg '((t (:foreground "#ff007c")))
  "Face for the first arg of __lg.")

(defun my-web-mode-hl__lg ()
  "Configure web mode such that the first arg of __lg(...) is high-lighted.
Function for `web-mode-hook'."
  (font-lock-add-keywords
   nil
   '(("\\_<__lg(\\('[^']*'\\)" ;; The regexp
      1 ;; decorate the first regexp group, i.e., the quoted string
      'my-web-mode-hl__lg ;; the face as we defined it
      t ;; this keyword should override any previous fontification
      ))
   t ;; append this to `font-lock-keywords`
   ))


(add-hook 'web-mode-hook #'my-web-mode-hl__lg)