Rails: pass data to javascript [duplicate]

Answer 1

I do something similar to, but simpler than gon. I have the following in my ApplicationController.

def javascript_variables(variables)
  @javascript_variables ||= {}
  @javascript_variables.merge!(variables)
end

Within a controller action I can then do something like

def some_action
  javascript_variables(user: current_user)
end

In my ApplicationHelper I have something like this

def javascript_variables(variables = nil)
  @javascript_variables ||= {}
  @javascript_variables.merge!(variables) and return if !variables.nil?

  output  = ''
  padding = @javascript_variables.keys.group_by(&:size).max.first

  @javascript_variables.each do |variable, value|
    output << "#{variable.to_s.ljust(padding)} = #{value.to_json},\n          "
  end

  raw "var " + output.strip.html_safe.gsub(/\,\Z/m, ';')
end

and finally in my layout's I have

This gives me something like this (from a real example in my application)