problem demo of https://github.com/mileszs/wicked_pdf/pull/182

amc-problem-demo.rb

# -*- coding: utf-8 -*-
# alias_method_chain problem demo
#  checked with rails 3.2.11
#
# usage:
#  rails new /tmp/amc-problem-demo --skip-bundle --skip-active-record --skip-test-unit -m amc-problem-demo.rb
#  cd /tmp/amc-problem-demo
#  bundle install
#  bundle exec rails server
#  open http://localhost:3000/
#  try to submit without file (expect "ajax:success")
#  try to submit with file (expect "ajax:error")
#  stop rails server
#  edit Gemfile # comment out "gem 'wicked_pdf'"
#  bundle exec rails server
#  open http://localhost:3000/
#  try to submit without file (expect "ajax:success")
#  try to submit with file (expect "ajax:success")



# remotipart 1.0.2 incompatible with jquery 1.9.0 (in jquery-rails 2.2.0)
gsub_file "Gemfile", /gem 'jquery-rails'(?!,)/, "gem 'jquery-rails', '~> 2.1.4'"
gem 'remotipart', '= 1.0.2'
gem 'wicked_pdf', '= 0.9.4'

insert_into_file "app/assets/javascripts/application.js", "//= require jquery.remotipart\n", :after => /^\/\/= require jquery_ujs\n(?!\/\/= require jquery\.remotipart\n)/

remove_file 'public/index.html'
uncomment_lines 'public/robots.txt', /User-Agent|Disallow/

create_file "app/controllers/some_controller.rb", <<-'RUBY'
class SomeController < ApplicationController
  def foo
  end
  def bar
    render formats: [:js]
  end
end
RUBY

create_file "app/views/some/foo.html.erb", <<-'HTML_ERB'
<h1>Some#foo</h1>
<div id="foo"></div>
<%= form_tag some_bar_path, remote: true do %>
  <%= file_field_tag "file" %>
  <%= submit_tag %>
<% end %>
HTML_ERB

create_file "app/views/some/bar.js.erb", <<-'JS_ERB'
$("#foo").append("posted.<br>")
JS_ERB

route "root to: 'some#foo'"
route "post 'some/bar'"

create_file "app/assets/javascripts/ajax.js", <<-'JS'
$(function(){
  $(document).on("ajax:error", function(xhr, status, error) {
    $("#foo").append("ajax:error:'" + error + "'.<br>");
  });
  $(document).on("ajax:success", function(data, status, xhr) {
    $("#foo").append("ajax:success.<br>");
  });
});
JS

amc-problem-demo.zip