How can I get rails to send javascript errors to the log, not alert?

Question

JavaScript errors to an alert box injure my soul. Is there a way to send it to console.log() instead of alert()?

Answer 1

You could override window.alert:

var oldAlert = window.alert; // reference to the original window.alert

window.alert = function(message) { 
  if (window.console && console.log) { 
    console.log(message); 
  } else { 
    oldAlert(message); // if console.log doesn't exist call window alert
  } 
} 

Answer 2

Yes, console.log("error message goes here")

Answer 3

It depends on the Javascript error. Since JavaScript is interpreted by the client, you would need to display the error messages client-side. The only real way to log errors in the server log file is if the error is happening on the server side before the Javascript is interpreted by the client.

Answer 4

You could try turning off RJS debugging of in your environment.rb file:

config.action_view.debug_rjs = false

This should turn off the alerts altogether. Another option would be overriding ActionView::Helpers::GeneratorMethods#to_s:

module ActionView
  module Helpers
    module GeneratorMethods
      def to_s #:nodoc:
        returning javascript = @lines * $/ do
          if ActionView::Base.debug_rjs
            source = javascript.dup
            javascript.replace "try {\n#{source}\n} catch (e) "
            javascript << "{ console.log('RJS error:\\n\\n' + e.toString()); console.log('#{source.gsub('\\','\0\0').gsub(/\r\n|\n|\r/, "\\n").gsub(/["']/) { |m| "\\#{m}" }}'); throw e }"
          end
        end
      end
    end
  end
end

I admit I'm out of my depth as far as overriding the method goes, and I don't know if it's a recommended practice. I haven't needed to do anything like this in my projects.

My personal preference would be to skip RJS and go with unobtrusive jQuery.