Removing newlines in ruby JSON - ruby-on-rails

Question

So, I am serialising an object in Ruby on Rails into JSON format, using to_json. The output produced is:
'{"description":"---\n- Nulla adipisci quia consequuntur nam ab et. Eius enim ad aut. Asperiores recusandae\n labore exercitationem.\n quos provident.\n","id":295,"name":"Animi enim dolorem soluta eligendi inventore quia distinctio magni.","privacy":0,"updated_at":"2012-11-18T22:24:17Z","user_id":1}'
This needs to be parsed by JSON.parse to deserialise the object in client-side javascript. At the moment, this is failing because of the newline characters \n in the "description" value. I've tried to encode the characters appropriately using gsub("\n","\\n") and other permutations, but I can't seem to find a string or regular expression that will correctly match the newlines (and only the newlines). I have tried /\n/, '\n', "\n", "\\n" (this matches everywhere on the string, for some reason), /\\n/ and so on, but haven't been able to find anything. Any ideas what I am missing?
Update: here's the code (javascript, but with embedded ruby) I'm trying to use to populate the javascript object (it's in an ERB view, hence the angle brackets):
var object = JSON.parse('<%= raw #object.to_json %>');
to_json is not overridden in my object code, just the standard rails method.

Answer 1

j = %Q!{"description":"---\n- Nulla adipisci quia consequuntur nam ab et. Eius enim ad aut. Asperiores recusandae\n labore exercitationem.\n quos provident.\n","id":295,"name":"Animi enim dolorem soluta eligendi inventore quia distinctio magni.","privacy":0,"updated_at":"2012-11-18T22:24:17Z","user_id":1}!
j.gsub! /\n/, '\\n'
JSON.parse j
# => {"description"=>"---\n- Nulla adipisci quia consequuntur nam ab et. Eius enim ad aut. Asperiores recusandae\n labore exercitationem.\n quos provident.\n", "id"=>295, "name"=>"Animi enim dolorem soluta eligendi inventore quia distinctio magni.", "privacy"=>0, "updated_at"=>"2012-11-18T22:24:17Z", "user_id"=>1}
Make your life easy, use single quotes around escaped characters when you need to manipulate them.
After the update…
var object = JSON.parse('<%= raw #object.to_json.gsub(/\n/, %q!\\n!) %>');

Answer 2

Your JSON includes a YAML string, so don't waste time trying to remove the line feeds, or you'll make things worse, or at least cause yourself to do too much work.
require 'json'
require 'yaml'
json = '{"description":"---\n- Nulla adipisci quia consequuntur nam ab et. Eius enim ad aut. Asperiores recusandae\n labore exercitationem.\n quos provident.\n","id":295,"name":"Animi enim dolorem soluta eligendi inventore quia distinctio magni.","privacy":0,"updated_at":"2012-11-18T22:24:17Z","user_id":1}'
hash = JSON[json]
puts YAML.load(hash['description'])
Outputs:
Nulla adipisci quia consequuntur nam ab et. Eius enim ad aut. Asperiores recusandae labore exercitationem. quos provident.
The JSON, after decoding back into a Ruby hash, looks like:
{"description"=>
"---\n- Nulla adipisci quia consequuntur nam ab et. Eius enim ad aut. Asperiores recusandae\n labore exercitationem.\n quos provident.\n",
"id"=>295,
"name"=>"Animi enim dolorem soluta eligendi inventore quia distinctio magni.",
"privacy"=>0,
"updated_at"=>"2012-11-18T22:24:17Z",
"user_id"=>1}
To turn it back into a true JSON string, with description not encoded as YAML, use:
hash['description'] = YAML.load(hash['description']).shift
puts hash.to_json
Which now looks like:
{"description":"Nulla adipisci quia consequuntur nam ab et. Eius enim ad aut. Asperiores recusandae labore exercitationem. quos provident.","id":295,"name":"Animi enim dolorem soluta eligendi inventore quia distinctio magni.","privacy":0,"updated_at":"2012-11-18T22:24:17Z","user_id":1}