Module: ActionController::Verification::ClassMethods

Defined in:
lib/action_controller/verification.rb

Overview

This module provides a class-level method for specifying that certain actions are guarded against being called without certain prerequisites being met. This is essentially a special kind of before_filter.

An action may be guarded against being invoked without certain request parameters being set, or without certain session values existing.

When a verification is violated, values may be inserted into the flash, and a specified redirection is triggered. If no specific action is configured, verification failures will by default result in a 400 Bad Request response.

Usage:

class GlobalController < ActionController::Base
  # Prevent the #update_settings action from being invoked unless
  # the 'admin_privileges' request parameter exists. The
  # settings action will be redirected to in current controller
  # if verification fails.
  verify :params => "admin_privileges", :only => :update_post,
         :redirect_to => { :action => "settings" }

  # Disallow a post from being updated if there was no information
  # submitted with the post, and if there is no active post in the
  # session, and if there is no "note" key in the flash. The route
  # named category_url will be redirected to if verification fails.

  verify :params => "post", :session => "post", "flash" => "note",
         :only => :update_post,
         :add_flash => { "alert" => "Failed to create your message" },
         :redirect_to => :category_url

Note that these prerequisites are not business rules. They do not examine the content of the session or the parameters. That level of validation should be encapsulated by your domain model or helper methods in the controller.

Instance Method Summary collapse

Instance Method Details

#verify(options = {}) ⇒ Object

Verify the given actions so that if certain prerequisites are not met, the user is redirected to a different action. The options parameter is a hash consisting of the following key/value pairs:

:params

a single key or an array of keys that must be in the params hash in order for the action(s) to be safely called.

:session

a single key or an array of keys that must be in the session in order for the action(s) to be safely called.

:flash

a single key or an array of keys that must be in the flash in order for the action(s) to be safely called.

:method

a single key or an array of keys–any one of which must match the current request method in order for the action(s) to be safely called. (The key should be a symbol: :get or :post, for example.)

:xhr

true/false option to ensure that the request is coming from an Ajax call or not.

:add_flash

a hash of name/value pairs that should be merged into the session's flash if the prerequisites cannot be satisfied.

:add_headers

a hash of name/value pairs that should be merged into the response's headers hash if the prerequisites cannot be satisfied.

:redirect_to

the redirection parameters to be used when redirecting if the prerequisites cannot be satisfied. You can redirect either to named route or to the action in some controller.

:render

the render parameters to be used when the prerequisites cannot be satisfied.

:only

only apply this verification to the actions specified in the associated array (may also be a single value).

:except

do not apply this verification to the actions specified in the associated array (may also be a single value).


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# File 'lib/action_controller/verification.rb', line 81

def verify(options={})
  before_filter :only => options[:only], :except => options[:except] do |c|
    c.__send__ :verify_action, options
  end
end