Since we removed the ActiveModel dependenxy from ActionPack at
166dbaa7 we don't need to require it
anymore.

Closes #7370

This pattern was introduced as a plugin by @dhh.

The original implementation can be found in
https://github.com/rails/routing_concerns

Updated documentation to demonstrate start_hour and end_hour options

We can avoid creating extra hashes with #merge, and use #merge! instead.

Further simplify the option_html_attributes method after the changes
introduced in dacbcbe5 to not escape the
html options here (since they're going to be escaped down the chain in
content tag).

if nil or an empty array is passed into form_for you get a horrible error message, this one is much more indicative of what the programmer needs to know to fix the problem.

Return the conditions from the keep_if call, and ignore the value
argument since it's not being used.

ActionDispatch railtie is a better place for
config.action_dispatch.default_headers settings, users can continue
overriding those settings in their configuration files if needed.

When you mount your application at a path, for example /myapp, server
should set SCRIPT_NAME to /myapp. With such information, rails
application knows that it's mounted at /myapp path and it should generate
routes relative to that path.

Before this patch, rails handled SCRIPT_NAME correctly only for regular
apps, but it failed to do it for mounted engines. The solution was to
hardcode default_url_options[:script_name], which is not the best answer
- it will work only when application is mounted at a fixed path.

This patch fixes the situation by respecting original value of
SCRIPT_NAME when generating application's routes from engine and the
other way round - when you generate engine's routes from application.

This is done by using one of 2 pieces of information in env - current
SCRIPT_NAME or SCRIPT_NAME for a corresponding router. This is because
we have 2 cases to handle:

- generating engine's route from application: in this situation
  SCRIPT_NAME is basically SCRIPT_NAME set by the server and it
  indicates the place where application is mounted, so we can just pass
  it as :original_script_name in url_options. :original_script_name is
  used because if we use :script_name, router will ignore generating
  prefix for engine

- generating application's route from engine: in this situation we
  already lost information about the SCRIPT_NAME that server used. For
  example if application is mounted at /myapp and engine is mounted at
  /blog, at this point SCRIPT_NAME is equal /myapp/blog. Because of that
  we need to keep reference to /myapp SCRIPT_NAME by binding it to the
  current router. Later on we can extract it and use when generating url

Please note that starting from now you *should not* use
default_url_options[:script_name] explicitly if your server already
passes correct SCRIPT_NAME to rack env.

(closes #6933)

No need to build valid_conditions array.
We can get all the data in place.

Thanks to Marek Labos & Nethemba

CVE-2012-3465

https://github.com/rails/journey/issues/40

Allow data attributes to be set as a first-level option for form_for, so you can write `form_for @record, data: { behavior: 'autosave' }` instead of `form_for @record, html: { data: { behavior: 'autosave' } }` *DHH*

We recommend the use of Unobtrusive JavaScript instead. For example:

  link_to "Greeting", "#", :class => "nav_link"

  $(function() {
    $('.nav_link').click(function() {
      // Some complex code

      return false;
    });
  });

or

  link_to "Greeting", '#', onclick: "alert('Hello world!'); return false", class: "nav_link"

for simple cases.

This reverts commit 3acdd652.