So, here are the steps you need to turn OOTB Emacs into the perfect environment for working on Javascript:

Auto-completion

Fizzing!

First up, you’re going to want decent auto-completion, so install the straightforwardly named auto-complete-mode. Due to some mode-name aliasing that goes on in the Emacs23 javascript mode, You’ll need to make sure it can find the relevant Javascript dictionary so

cd path/to/auto-complete/dict
ln -s javascript-mode js-mode

and then add to your .emacs:

(add-to-list 'load-path "~/path-to/auto-complete")
; Load the default configuration
(require 'auto-complete-config)
; Make sure we can find the dictionaries
(add-to-list 'ac-dictionary-directories "~/emacs/auto-complete/dict")
; Use dictionaries by default
(setq-default ac-sources (add-to-list 'ac-sources 'ac-source-dictionary))
(global-auto-complete-mode t)
; Start auto-completion after 2 characters of a word
(setq ac-auto-start 2)
; case sensitivity is important when finding matches
(setq ac-ignore-case nil)

You now have auto-completion for all variable names in all open Javascript buffers, as well as for standard syntax words (setTimeout, parseInt, onFocus etc).

Snippeting

Not content with that, we’ll also want some kind of intelligent snippet package right – how many times do you really want to type all those semicolons and curly braces? Once is good for me.

The excellent Yasnippet provides this (check out the youtube demo if you’ve not come across it before)

Once you’ve got that downloaded and installed, you’ll want some Javascript snippets to load in, the ones I use, for standard Javascript and jQuery can be downloaded from here, and then the directory provided by that tarfile needs to go in yasnippet/snippets/text-mode

So for our .emacs:

(add-to-list 'load-path "~/path/to/yasnippet")
;; Load the library
(require 'yasnippet)
(yas/initialize)
;; Load the snippet files themselves
(yas/load-directory "~/path/to/yasnippet/snippets/text-mode")
;; Let's have snippets in the auto-complete dropdown
(add-to-list 'ac-sources 'ac-source-yasnippet)

Syntax Checking

Whoops...

One of the problems with Javascript programming is that the feedback loop for syntax errors is *slow* – if you’re working with the web you have to wait for a whole pageload. So we’ll want on-the-fly error checking.

Kevin Turner originally wrote Lintnode, which runs a lighthweight node.js server that passes your file to Douglas Crockford’s JSLint to integrate with Flymake – the Emacs solution for on-the-fly syntax checking. The fork I’m currently maintaining at Github contains some enhancements such as automatic initialization and JSLint options passed from Emacs that the original has yet to merge in. Given that JSLint frequently complains about things that you might like it to er, not complain about, the ability to change the options with the lintnode-jslint-excludes variable makes this far more useable.

So:

Install node.js and npm (The package manager for node)

Get lintnode and the dependencies

git clone https://github.com/davidmiller/lintnode.git
cd lintnode
npm install express connect-form haml underscore

Then we need this in our .emacs:

(add-to-list 'load-path "~/path/to/lintnode")
(require 'flymake-jslint)
;; Make sure we can find the lintnode executable
(setq lintnode-location "~/path/to/lintnode")
;; JSLint can be... opinionated
(setq lintnode-jslint-excludes (list 'nomen 'undef 'plusplus 'onevar 'white))
;; Start the server when we first open a js file and start checking
(add-hook 'js-mode-hook
          (lambda ()
            (lintnode-hook)))

Syntax errors will now be given a red background without having to leave the comfort of Emacs.

Even better, if we install the Flymake Cursor package, we get the error message in the minibuffer when the cursor is on a line with an error.

Easy Mistake!

Get the source from http://www.emacswiki.org/emacs/flymake-cursor.el and then add to your .emacs:

(add-to-list 'load-path "~/emacs/minor-modes")
;; Nice Flymake minibuffer messages
(require 'flymake-cursor)

Edit:

As Jesse and Magnar point out in the comments, it’s probably a better idea to not exclude ‘undef from the jslint errors, but rather to declare global variables at the top of your .js file

 /*global $ */

This way you can let jslint know about other libraries you are using, but still get the checks for undefined variables in your own code.

Code folding

Underscore outline

Especially if you’re dealing with large projects, the ability to hide portions of code can be great for maintaining focus. Emacs comes with this built in, but you have to enable it, so returning to our .emacs:

(add-hook 'js-mode-hook
          (lambda ()
            ;; Scan the file for nested code blocks
            (imenu-add-menubar-index)
            ;; Activate the folding mode
            (hs-minor-mode t)))

This means that when your cursor is in the function…

var Foo = 42;
addFoo = function(num){
    // Let's add the meaning of life to
    // our `num` - it'll be fun!
    var meaningful;
    meaningful = num + Foo;
};

… and you M-x hs-hide-block, the function turns into:

Var Foo = 42;
addFoo = function(num){...};

To my taste the default keybinding of C-c @ C-h to hide blocks is somewhat perverse, so I’d recommend this in your .emacs:

;; Show-hide
(global-set-key (kbd "") 'hs-show-block)
(global-set-key (kbd "") 'hs-show-all)
(global-set-key (kbd "") 'hs-hide-block)
(global-set-key (kbd "") 'hs-hide-all)

YMMV.

Javascript Console

Having a REPL for the language you’re working with close to hand is basically required for me to enjoy working with it. Now that we’ve installed node.js, though, we can have us a Javascript console inside Emacs with js-comint…

Once you’ve grabbed the file, your .emacs should have:

(add-to-list 'load-path "~/path/to/js-comint")
(require 'js-comint)
;; Use node as our repl
(setq inferior-js-program-command "node")
 
(setq inferior-js-mode-hook
      (lambda ()
        ;; We like nice colors
        (ansi-color-for-comint-mode-on)
        ;; Deal with some prompt nonsense
        (add-to-list 'comint-preoutput-filter-functions
                     (lambda (output)
                       (replace-regexp-in-string ".*1G\.\.\..*5G" "..."
                     (replace-regexp-in-string ".*1G.*3G" ">" output))))

You can then run a Javascript REPL with M-x run-js and also send portions of files by selecting them and then running M-x send-region. Neat.

By way of conclusion

There are a few other tweaks that make my Javascripting just that little bit nicer, but they’re more personal Emacs setup than anything specific to Javascript. So, there you have it, the perfect Javascript editing environment.

Love regards etc

This mode provides integration with the django management commands within emacs, as well as test integration, a minor-mode with syntax highlighting for editing templates, will determine whether you are using Fabric or Buildout, as well as much more!

This mode is under active development, so please file any bugs at the Github page, and feel free to provide any feedback/feature requests etc.

Current features include:

• Run dev server in an emacs buffer [C-c C-p r]
• * Checks to see if runserver_plus is available
• * If not uses in-built runserver
• Jump to current project in browser (start server if required) [C-c C-p b]
• Run test case at point in buffer [C-c C-p t]
• Run tests for current app in buffer [C-c C-p t]
• Run Syncdb on current project
• Management commands for current project in interactive buffer
• South integration – run south convert, schemamigration, migrate
• Run django shell in buffer [C-c C-p s]
• * Checks for shell_plus
• * If not defaults to shell
• Fabric integration [C-c C-p f]
• Startapp and dumpdata on current project within emacs
• Database integration with Emacs sql-mode interactive buffer [C-c C-c d
• Django Template minor mode with syntax highlighting for django

template tags

• Snippet collection for django
• generate tags table for project
• run manage commands in interactive buffer
• Buildout integration
• Generate TAGS table for project to enable quick navigation
• Jump to template at point or from editing view [C-c C-p g t]

Grab it while it’s hot!

We must plan for freedom, and not only for security, if for no other reason than that only freedom can make security secure.

Karl Popper – The Open Society and its Enemies

Every society needs a diversion that doesn’t do any physical harm, but keeps those people who prefer to live in fantasy worlds occupied. Certain newspapers cater to this segment of the populace, and the typographic styles reflect their journalistic attitude toward the truth.

Stop stealing sheep and find out how type works

LA MUSE VÉNALE

Ma pauvre muse, hélas ! qu’as-tu donc ce matin ?
Tes yeux creux sont peuplés de visions nocturnes,
Et je vois tour à tour réfléchis sur ton teint
La folie et l’horreur, froides et taciturnes.

Le succube verdâtre et le rose lutin
T’ont-ils versé la peur et l’amour de leurs urnes ?
Le cauchemar, d’un poing despotique et mutin,
T’a-t-il noyée au fond d’un fabuleux Minturnes ? [  23 ]

Je voudrais qu’exhalant l’odeur de la santé
Ton sein de pensers forts fût toujours fréquenté,
Et que ton sang chrétien coulât à flots rhythmiques,

Comme les sons nombreux des syllabes antiques,
Où règnent tour à tour le père des chansons,
Phœbus, et le grand Pan, le seigneur des moissons.

Charles Baudelaire was once but is no longer.

The large print giveth and the small print taketh away.

- Tom Waits

Which is a wonderful thought enough for this time of day, moreover & however take good care of the following video, in which Mr Tom Waits explores issues close to all of us, explaining the meaning of the word/acronym/god PEHDTSCKJMBA for those of you who are yet to become acquainted, in one of the finest press conferences you are likely to see in the next ten minutes:

Quote found via QuotesOnDesign.com

“lost his will to live after the death of a younger sister.”

[Milton Acorn Wikipedia]

Milton Acorn

[Photo by @SheldonGrimson]

But more than just that, he was also an excellent poet whose work has a fragile brutality, dragged along by an absurdist sense of humour… Enjoyable:

In the elephant’s five-pound brain
Dwarves have an incredible vicious sincerity,
A persistent will to undo things. The beast cannot grasp
The convolutions of destruction, always his mind
Turns to other things – the vastness of green
And of frangibility of forest. If only once he could descend
To trivialities he’d sweep the whole earth clean of his tormentors
In one sneeze so mighty as to be observed from Mars.

In the elephant’s five-pound brain
Sun and moon are the pieces in a delightfully complex ballgame
That have to do with him…never does he doubt
The sky has opened and rain and thunder descend
For his special ministration. He dreams of mastodons
And mammoths and still his pride beats
Like the heart of the world, he knows he could reach
To the end of space if he stood still and imagined the effort.

[excerpt from The Natural History of Elephants]

Frankly, that should be enough for anyone to go and investigate further.

P.S. I was also recently made aware that Satan once lived in the White House, incarnated as the dog of the Second Lady Abigail Adams

In terms of blogs, there are very few that I automatically read as soon as a new post turns up in my google reader. a working library is one of these.

Mandy Brown shares the most interesting passages from her current reading, along with her thoughts and observations on life, philosophy, criticism & whatever else. It is by far the most intellectualised thing that turns up in my favourites folder, but always welcome to shift me into a different mental gear.

Recent favourites have been Robin Kinross on typography, Adorno on Marxism and Terry Eagleton on Ideology.

The stimulation of receiving someones thoughts and observations along with key passages as they read fascinating books is brilliant. Short, dense posts with a real weight behind them this is a series of deft punches rather than lectures, and all the better for it.

Thank you