Emacs mode to edit JSON

Question

Does anybody know a good Emacs mode to edit JSON? An app I am working on uses a JSON based communication protocol and having the data nicely indented and syntax-highlighted would help me a lot in the process of figuring it out.

Answer 1

+1 for Josh's json-mode -- works well for me. I added

(defun beautify-json ()   (interactive)   (let ((b (if mark-active (min (point) (mark)) (point-min)))         (e (if mark-active (max (point) (mark)) (point-max))))     (shell-command-on-region b e      "python -m json.tool" (current-buffer) t))) 

and

(define-key json-mode-map (kbd "C-c C-f") 'beautify-json) 

to json-mode.el to make the shell command invocation easier.

UPDATE: For those of you with a need/desire to do this with unicode, see my question here. The upshot is rather than using:

python -m json.tool 

you will want to use

python -c 'import sys,json; data=json.loads(sys.stdin.read()); print json.dumps(data,sort_keys=True,indent=4).decode("unicode_escape").encode("utf8","replace")' 

This both beautifies the JSON as well as preserving the original Unicode content.

Answer 2

js-mode supports syntax highlighting and indentation for json files.

This is as of Emacs 23.2, when espresso-mode was incorporated into Emacs and renamed js-mode.

Check it out: http://www.nongnu.org/espresso/