I'm trying to get the JSON object from a JSON outputted string from a Rails app. Currently in JavaScript I'm doing:

data = "<%= @chromosomes.html_safe %>";

However, since there are quotes at the beginning and end of the JSON object, it is not being rendered as a JSON object. Instead it is doing something like

 data = "[{"name":"YHet","organism_id":"4ea9b90e859723d3f7000037"}]"

Is there a way that I can remove the beginning and end quotes so that the object is treated as an array instead of a string?

I'm trying to get the JSON object from a JSON outputted string from a Rails app. Currently in JavaScript I'm doing:

data = "<%= @chromosomes.html_safe %>";

However, since there are quotes at the beginning and end of the JSON object, it is not being rendered as a JSON object. Instead it is doing something like

 data = "[{"name":"YHet","organism_id":"4ea9b90e859723d3f7000037"}]"

Is there a way that I can remove the beginning and end quotes so that the object is treated as an array instead of a string?

• javascript
• ruby-on-rails
• json

• I don't know what "html_safe" means exactly, but just as a note, it's not necessarily correct to use HTML-safe escapes ("&lt;" for "<" etc) when you're dropping something directly into JavaScript source. – Pointy Commented Apr 9, 2012 at 15:04
• @Pointy in this case it probably is correct to use html_safe, since he probably wants [{"name":"<script src='badwebsite./bad.js'></script>","organism_id":"..."}] instead of [{"name":"<script src='badwebsite./bad.js'></script>","organism_id":"..."}]. – Peter C Commented Apr 9, 2012 at 15:11
• @alpha123 yes sometimes it's correct to use HTML escapes, but not always; for example, if the "organism_id" can contain HTML characters, it may be wrong to replace them if that string is purely intended to work inside JavaScript code and never be injected into the HTML. – Pointy Commented Apr 9, 2012 at 15:21
• @Pointy correct, although it looks like organism_id is a hash or GUID or something else not going to contain < or > or &, and name probably will be injected into HTML at some point. I'd say escape. – Peter C Commented Apr 9, 2012 at 15:25

5 Answers 5

Why don't you do:

data = <%= @chromosomes.html_safe %>;

Sidenote:

I hope you do something like:

@chromosomes = [{ name: "YHet", organism_id: "foo" }].to_json

If you are using jQuery you can do the following

var data = jQuery.parseJSON('[{"name":"YHet","organism_id":"4ea9b90e859723d3f7000037"}]');

Use JSON object that is included in most of browsers or if you are using jQuery use $.jsonParse method that try to use JSON object if defined otherwise parse using eval or some safer way.

On controller

@my_var = MyObj.find_by_id(4).to_json

On page in haml way.

var my_json = $.parseJSON("#{j @my_var}"); //used JQuery to parser JSON string

Use eval:

var dataObject = eval('(' + dataString + ')');