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js2-mode instructions Introductionjs2-mode is a new JavaScript editing mode for GNU Emacs. It aims to be more like an IDE (such as Eclipse or IntelliJ) than existing Emacs language modes. There is a lot of work left to do to achieve this goal, but it's got a pretty good start: - it offers the usual features from other Emacs modes
- it supports the JavaScript language up through version 1.7
- it has a real recursive-descent parser
- it highlights syntax errors and underlines warnings
- it supports collapsing function-body and block-comment definitions
- it has some preliminary support for IMenu (to be improved soon)
- it knows about jsdoc and highlights tags in jsdoc comments
- it has a set of typing helpers to make editing easier
Most of the mode's features are customizable via M-x customize. DetailsTo install js2-mode: - download the latest source distribution file, js2-XXXXXXXX.el
- put it in your Emacs load-path somewhere as js2.el
- in Emacs, M-x byte-compile-file RE js2.el RET
- add these lines to your .emacs file:
(autoload 'js2-mode "js2" nil t)
(add-to-list 'auto-mode-alist '("\\.js$" . js2-mode))It will refuse to run unless you have byte-compiled it. You must byte-compile it with your version of Emacs because different versions of Emacs have different byte-compiled formats. Usage NotesInvoke M-x customize-group RET js2-mode RET to see the configuration options. This mode does not have customizable indentation the way cc-engine modes do (e.g. java-mode, c-mode, objc-mode). It is a significant amount of work to create a customizable indenter. Instead, js2-mode uses an indentation guesser (based on Karl Landström's "javascript.el" guesser), plus "bounce-indenting". When you hit TAB the first time to indent a line, it indents to what it thinks is the most likely indentation point, and it computes a set of other possibilities. If you hit TAB repeatedly, it cycles among these possibilities. There are obvious downsides to this approach, but hopefully over time the indentation support will improve. Installing from source codeAs an alternate way to install the mode, you can download the source files from the svn repository (from the Source tab above), put them in your load-path, and byte-compile each of them. The mode runs without being byte-compiled in "developer mode" (i.e. from source), so be careful, since it's really really slow for large files. If you're using the svn sources, you can get the latest updates between official releases.
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Delete comment Comment by glyphobet, Today (moments ago)
I had no idea how to "put it in your Emacs load-path somewhere" and various Google searches were no help. Here's what eventually worked for me, in emacs:
1. make the directory ~/.emacs.d/js2/
2. put js2.el and js2.elc in ~/.emacs.d/js2/`
3. add these three lines to your ~/.emacs file:
(setq load-path (append (list (expand-file-name "~/.emacs.d/js2")) load-path)) (autoload 'js2-mode "js2" nil t) (add-to-list 'auto-mode-alist '("\\.js$" . js2-mode))Thanks, got it now!
Is it possible to add some supports for Ajax module like JQuery, Dojo, YUI and so on?
Byte compiling throws an error in emacs-cvs from yesterday:
Compiling file /home/myusername/.elisp/js2.el at Thu May 15 15:09:23 2008 js2.el:6787:24:Error: Variable binding depth exceeds max-specpdl-size
The path for load-paths is normally the lisp directory.
c:/emacs/lisp
for example
@mixandgo, I was able to compile successfully from the command line:
shell> emacs --batch --eval '(byte-compile-file "js2-20080616a.el")'
I'm running Emacs 23.0.60.1
I have the same problem with CVS emacs, I can compile it as the comment above sugested, but when I try to open a javascript file I get this error:
My js2.elc file is there.
emacs-version
This works on Ubuntu 8.04 (Hardy Heron): http://ubuntuforums.org/showpost.php?p=675916&postcount=3
Note that emacs must be opened with 'sudo' to have permission to write to "/usr/share/emacs/<version>/lisp".
If you have error message "You must byte-compile js2-mode before using it.", then check nXhtml package. It uses OLD js2 mode with name js2-new.el... :(
Hey, I just got it installed, opened my first JS file to start editing... what is up with the behavior of TAB and auto-indenting?! Hitting tab mutiple times keeps re-indenting it to different levels! I differs from line-to-line, in loops like (0, 4, 0, 4, ...) or (0, 4, 8, 0, 4, 8, ...) or (12, 8, 4, 12, 8, 4, ...), or (16, 12, 0, 16, 12, 0, ...)
Syntax hiliting is great, but without smart auto-indenting, I'd rather use my javascript-mode. Am I missing something?
It cycles through various TAB positions based on the previous line, bracket etc. (it's all on his blog), which is actually brilliant because keep hitting TAB in an IDE and it will just keep tabbing the line out, which is hardly ever what you want. Just keep hitting TAB until it's where you want. JS-2 mode also has a syntax checker, which I don't think javascript-mode has unless I'm misinformed.
Coupled with Ejacs (great name), JavaScript? shell, this is a great setup. (Thanks, Steve)
But, all other code editing modes in emacs, Perl, PHP, java, C, etc have the same tab behavior, you hit tab (any number of times, wherever you are in a line) and it indents that line properly to the One place the indentation makes sense. Can't the syntax reader just read the surrounding code and pick the one place the indent should be? e.g the K&R style? Yeah, maybe it's a step up from other IDE's, but it's a major step back from the emacs usual behavior.
If you get You must byte-compile js2-mode before using it., also make sure that you have named the file js2.el and not, say js2-20090723a.el.
I had the same error as Gopal above and can confirm that the command line compilation did work with my GNU Emacs 23.0.96.1
unlox775: You can set js2-bounce-indent-flag to nil in order to get your traditional indentation behaviour
I'm including the two lines specified in the instructions to my .emacs file:
(autoload 'js2-mode "js2" nil t) (add-to-list 'auto-mode-alist '("\\.js$" . js2-mode))
The mode is loading properly, but it's not activated immediately. Is there a way of avoiding hitting M-x js2-mode each time I want to turn it on?
A) @adambossy: Works fine (mode is loaded and activated immediately) on 'GNU Emacs 22.2.1 (i486-pc-linux-gnu, X toolkit, Xaw3d scroll bars) of 2008-09-05 on vernadsky, modified by Ubuntu'.
B)Separately, I also suggest adding another add-to-list to get '.json' files in addition to '.js' files.
C)Is there a way to have js2-mode parse/load an ordered list of js files on activation? That way (of course), support could be extended to js frameworks.
D) Awesome JavaScript? mode! It doesn't have Aptana's speed/responsiveness issue.