JavaScript with Google Closure on emacs

gistfile1.txt

Get google closure compiler to evaluate your javascript code on your emacs
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- Download the google closure compiler, unzip it and place ``compiler.jar`` somewhere accessible 
(e.g. ``~/bin/compiler.jar``)::

http://closure-compiler.googlecode.com/files/compiler-latest.zip


- Create a shell script to run closure on a file (e.g. closure.sh)::

!#/bin/bash
java -jar ~/bin/compiler.jar --warning_level VERBOSE --js $1 --js_output_file /dev/null


- Add the following to your emacs config make sure you edit the filename to match the name of the 
previous script (closure.sh in this case) and it is available on the PATH of your system::

(when (load "flymake" t)
  (defun flymake-closure-init ()
    (let* ((temp-file (flymake-init-create-temp-buffer-copy
		       'flymake-create-temp-inplace))
           (local-file (file-relative-name
                        temp-file
                        (file-name-directory buffer-file-name))))
      (list "closure.sh" (list local-file))))
  (add-to-list 'flymake-allowed-file-name-masks
               '("\\.js\\'" flymake-closure-init)))


- Add flymake to your javascript mode hook::

(add-hook 'javascript-mode-hook
	  (lambda () (flymake-mode t)))


- Get some javascript done, and the compiler will warn you if something is not quite right.

Bonus points:

- To show what the warning or the error is about on the mode line you will need ``flymake-cursor``::

(load-library "flymake-cursor")


- To change the appearance of the errors and warnings, you can underline as well ``:underline "#ff0000"``::

(custom-set-faces
 '(flymake-errline ((((class color)) (:background "#ffffd7"))))
 '(flymake-warnline ((((class color)) (:background "#0a2832")))))


References::

Originally from: "http://www.emacswiki.org/emacs/FlyMake#toc9
Closure compiler:  http://code.google.com/closure/compiler/docs/gettingstarted_app.html