pretty printing in cljs

Question

I am trying to pretty print a JSON from clojurescript, on the browser's console.

I found the following link - How can I pretty-print JSON using JavaScript?

The above link provides the following js - JSON.stringify(obj, undefined, 2)

The following translation in cljs doesnt work (.stringify js/JSON obj undefined 2)

Is there any native way in cljs for pretty printing?
Any ideas why the above cljs expression doesnt work ?

What you get when you use `(.stringify js/JSON obj undefined 2)`? — Abimaran Kugathasan, Mar 25 '13 at 05:47
What is ```obj```? If it's a clojure map you'll need to convert it to a js object first. — bmaddy, Mar 25 '13 at 17:00

dnolen · Accepted Answer · 2015-05-11T15:25:20.463

11

UPDATE: ClojureScript now has a full port of clojure.pprint in the form of cljs.pprint.

There's also a fipp which is narrower in scope and likely a bit faster.

edited May 11 '15 at 15:25

answered Mar 26 '13 at 14:24

dnolen

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ClojureScript has two pretty-printers available: https://github.com/shaunlebron/cljs-pprint https://github.com/brandonbloom/fipp – ag0rex May 10 '15 at 19:31

Dustin Getz · Answer 2 · 2014-10-07T23:52:04.560

5

cljs.user> (.stringify js/JSON (clj->js {:foo 42}) nil 2)
"{\n  \"foo\": 42\n}"

cljs.user> (pr-str {:foo 42})
"{:foo 42}"

edited Oct 07 '14 at 23:52

answered Oct 07 '14 at 23:44

Dustin Getz

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vikeri · Answer 3 · 2015-07-06T21:43:03.810

The following converts a Clojure map (object) to JSON and prints it in the console as an object that can hence leverage the browsers inspect JSON functionality:

(.dir js/console (clj->js object))

EDIT: While pretty printing is really nice, in the developer console I still prefer the ability to browse the data structure as a tree and now frequently use cljs-devtools. It is a library that gives you an interactive data tree that can be expanded as a normal js-object but for vanilla clojure without having to convert to js, meaning :keywords, {:ma "ps"} and the rest of the clj-family.

At the moment it requires you to add a leiningen dependency and some code to your project and to use Chrome Canary.

score 2 · Answer 4 · answered May 09 '15 at 13:31

2

clojure.pprint has been ported to ClojureScript with release 0.0-3255. It is called cljs.pprint.

answered May 09 '15 at 13:31

Leon Grapenthin

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score 1 · Answer 5 · answered Dec 11 '14 at 16:39

Indeed, someone needs to port clojure.pprint, which seems to be going on here shaunlebron/cljs-pprint.

In the mean time, if you are running on NodeJS, I use prettyjson from npm.

(ns foo (:require [cljs.nodejs :as nodejs]
                  [cljs.core :refer [clj->js]]))
(nodejs/enable-util-print!)
(def render (.-render (nodejs/require "prettyjson")))
(defn pp [value] (println (render (clj->js value))))

It then prints the value in colorised YAML:

ClojureScript:foo> (pp {:a 123 :foo ["baz" 42]})
a:   123
foo:
  - baz
  - 42

This is just a hack, but at least is is readable.

pretty printing in cljs

5 Answers5