Today I noticed that whenever using some of the Prototype Helpers in Rails (such as link_to_remote or remote_function), it was setting by default the evalScripts parameter to true. For those who don’t know, Prototype uses evalScripts to evaluate anything in <script> tags from the response text. This was giving me major headaches in a piece of code today.

Looking at the previously-linked API page for the Prototype Helpers, there was no mention on how to set this parameter to false. I thought that simply passing :evalScripts => false as an option to the helper would do the trick, but it didn’t. So I had to dig into Rails source code to see if there was any way to set this to false.

When reading the prototype_helper.rb file, which houses the helpers that generate the HTML / JavaScript code, I noticed that there’s an option named :script that allows the developer to set the value of the evalScripts parameters in the generated JavaScript code.

In short, passing :script => false as an option to your Prototype Helper code on the view will correctly set the evalScripts parameter to false.

Hope this helps someone!