How to pass Ruby variables to a JavaScript function in a Rails view?

Question

I\'m wondering what the best practice is for passing variables to JavaScript functions in a rails view. Right now I\'m doing something like:

<% content_f         


        

Answer 1

Note that if you aren't using escape_javascript in a view, you can include it in your ruby code like so:

require 'action_view/helpers/javascript_helper'
include ActionView::Helpers::JavaScriptHelper
# escape_javascript is available here.

or if that wont work for you, then copy the source of the function in to your code, if need be:

  JS_ESCAPE_MAP = {
    '\\'    => '\\\\',
    " '<\/',
    "\r\n"  => '\n',
    "\n"    => '\n',
    "\r"    => '\n',
    '"'     => '\\"',
    "'"     => "\\'"
  }

  JS_ESCAPE_MAP["\342\200\250".dup.force_encoding(Encoding::UTF_8).encode!] = "
"
  JS_ESCAPE_MAP["\342\200\251".dup.force_encoding(Encoding::UTF_8).encode!] = "
"

  # Escapes carriage returns and single and double quotes for JavaScript segments.
  #
  # Also available through the alias j(). This is particularly helpful in JavaScript
  # responses, like:
  #
  #   $('some_element').replaceWith('<%= j render 'some/element_template' %>');
  def escape_javascript(javascript)
    if javascript
      result = javascript.gsub(/(\\|<\/|\r\n|\342\200\250|\342\200\251|[\n\r"'])/u) { |match| JS_ESCAPE_MAP[match] }
      javascript.html_safe? ? result.html_safe : result
    else
      ""
    end
  end