require 'action_controller/mime_type'
require 'action_controller/request'
require 'action_controller/response'
require 'action_controller/routing'
require 'action_controller/url_rewriter'
require 'drb'
require 'set'
module ActionController #:nodoc:
class ActionControllerError < StandardError #:nodoc:
end
class SessionRestoreError < ActionControllerError #:nodoc:
end
class MissingTemplate < ActionControllerError #:nodoc:
end
class RoutingError < ActionControllerError #:nodoc:
attr_reader :failures
def initialize(message, failures=[])
super(message)
@failures = failures
end
end
class UnknownController < ActionControllerError #:nodoc:
end
class UnknownAction < ActionControllerError #:nodoc:
end
class MissingFile < ActionControllerError #:nodoc:
end
class SessionOverflowError < ActionControllerError #:nodoc:
DEFAULT_MESSAGE = 'Your session data is larger than the data column in which it is to be stored. You must increase the size of your data column if you intend to store large data.'
def initialize(message = nil)
super(message || DEFAULT_MESSAGE)
end
end
class DoubleRenderError < ActionControllerError #:nodoc:
DEFAULT_MESSAGE = "Render and/or redirect were called multiple times in this action. Please note that you may only call render OR redirect, and only once per action. Also note that neither redirect nor render terminate execution of the action, so if you want to exit an action after redirecting, you need to do something like \"redirect_to(...) and return\". Finally, note that to cause a before filter to halt execution of the rest of the filter chain, the filter must return false, explicitly, so \"render(...) and return false\"."
def initialize(message = nil)
super(message || DEFAULT_MESSAGE)
end
end
class RedirectBackError < ActionControllerError #:nodoc:
DEFAULT_MESSAGE = 'No HTTP_REFERER was set in the request to this action, so redirect_to :back could not be called successfully. If this is a test, make sure to specify @request.env["HTTP_REFERER"].'
def initialize(message = nil)
super(message || DEFAULT_MESSAGE)
end
end
# Action Controllers are the core of a web request in Rails. They are made up of one or more actions that are executed
# on request and then either render a template or redirect to another action. An action is defined as a public method
# on the controller, which will automatically be made accessible to the web-server through Rails Routes.
#
# A sample controller could look like this:
#
# class GuestBookController < ActionController::Base
# def index
# @entries = Entry.find(:all)
# end
#
# def sign
# Entry.create(params[:entry])
# redirect_to :action => "index"
# end
# end
#
# Actions, by default, render a template in the app/views directory corresponding to the name of the controller and action
# after executing code in the action. For example, the +index+ action of the +GuestBookController+ would render the
# template app/views/guestbook/index.rhtml by default after populating the @entries instance variable.
#
# Unlike index, the sign action will not render a template. After performing its main purpose (creating a
# new entry in the guest book), it initiates a redirect instead. This redirect works by returning an external
# "302 Moved" HTTP response that takes the user to the index action.
#
# The index and sign represent the two basic action archetypes used in Action Controllers. Get-and-show and do-and-redirect.
# Most actions are variations of these themes.
#
# == Requests
#
# Requests are processed by the Action Controller framework by extracting the value of the "action" key in the request parameters.
# This value should hold the name of the action to be performed. Once the action has been identified, the remaining
# request parameters, the session (if one is available), and the full request with all the http headers are made available to
# the action through instance variables. Then the action is performed.
#
# The full request object is available with the request accessor and is primarily used to query for http headers. These queries
# are made by accessing the environment hash, like this:
#
# def server_ip
# location = request.env["SERVER_ADDR"]
# render :text => "This server hosted at #{location}"
# end
#
# == Parameters
#
# All request parameters, whether they come from a GET or POST request, or from the URL, are available through the params method
# which returns a hash. For example, an action that was performed through /weblog/list?category=All&limit=5 will include
# { "category" => "All", "limit" => 5 } in params.
#
# It's also possible to construct multi-dimensional parameter hashes by specifying keys using brackets, such as:
#
#
#
#
# A request stemming from a form holding these inputs will include { "post" => { "name" => "david", "address" => "hyacintvej" } }.
# If the address input had been named "post[address][street]", the params would have included
# { "post" => { "address" => { "street" => "hyacintvej" } } }. There's no limit to the depth of the nesting.
#
# == Sessions
#
# Sessions allows you to store objects in between requests. This is useful for objects that are not yet ready to be persisted,
# such as a Signup object constructed in a multi-paged process, or objects that don't change much and are needed all the time, such
# as a User object for a system that requires login. The session should not be used, however, as a cache for objects where it's likely
# they could be changed unknowingly. It's usually too much work to keep it all synchronized -- something databases already excel at.
#
# You can place objects in the session by using the session method, which accesses a hash:
#
# session[:person] = Person.authenticate(user_name, password)
#
# And retrieved again through the same hash:
#
# Hello #{session[:person]}
#
# For removing objects from the session, you can either assign a single key to nil, like session[:person] = nil, or you can
# remove the entire session with reset_session.
#
# By default, sessions are stored on the file system in RAILS_ROOT/tmp/sessions. Any object can be placed in the session
# (as long as it can be Marshalled). But remember that 1000 active sessions each storing a 50kb object could lead to a 50MB store on the filesystem.
# In other words, think carefully about size and caching before resorting to the use of the session on the filesystem.
#
# An alternative to storing sessions on disk is to use ActiveRecordStore to store sessions in your database, which can solve problems
# caused by storing sessions in the file system and may speed up your application. To use ActiveRecordStore, uncomment the line:
#
# config.action_controller.session_store = :active_record_store
#
# in your environment.rb and run rake db:sessions:create.
#
# == Responses
#
# Each action results in a response, which holds the headers and document to be sent to the user's browser. The actual response
# object is generated automatically through the use of renders and redirects and requires no user intervention.
#
# == Renders
#
# Action Controller sends content to the user by using one of five rendering methods. The most versatile and common is the rendering
# of a template. Included in the Action Pack is the Action View, which enables rendering of ERb templates. It's automatically configured.
# The controller passes objects to the view by assigning instance variables:
#
# def show
# @post = Post.find(params[:id])
# end
#
# Which are then automatically available to the view:
#
# Title: <%= @post.title %>
#
# You don't have to rely on the automated rendering. Especially actions that could result in the rendering of different templates will use
# the manual rendering methods:
#
# def search
# @results = Search.find(params[:query])
# case @results
# when 0 then render :action => "no_results"
# when 1 then render :action => "show"
# when 2..10 then render :action => "show_many"
# end
# end
#
# Read more about writing ERb and Builder templates in link:classes/ActionView/Base.html.
#
# == Redirects
#
# Redirects are used to move from one action to another. For example, after a create action, which stores a blog entry to a database,
# we might like to show the user the new entry. Because we're following good DRY principles (Don't Repeat Yourself), we're going to reuse (and redirect to)
# a show action that we'll assume has already been created. The code might look like this:
#
# def create
# @entry = Entry.new(params[:entry])
# if @entry.save
# # The entry was saved correctly, redirect to show
# redirect_to :action => 'show', :id => @entry.id
# else
# # things didn't go so well, do something else
# end
# end
#
# In this case, after saving our new entry to the database, the user is redirected to the show method which is then executed.
#
# == Calling multiple redirects or renders
#
# An action should conclude with a single render or redirect. Attempting to try to do either again will result in a DoubleRenderError:
#
# def do_something
# redirect_to :action => "elsewhere"
# render :action => "overthere" # raises DoubleRenderError
# end
#
# If you need to redirect on the condition of something, then be sure to add "and return" to halt execution.
#
# def do_something
# redirect_to(:action => "elsewhere") and return if monkeys.nil?
# render :action => "overthere" # won't be called unless monkeys is nil
# end
#
class Base
DEFAULT_RENDER_STATUS_CODE = "200 OK"
include Reloadable::Subclasses
# Determines whether the view has access to controller internals @request, @response, @session, and @template.
# By default, it does.
@@view_controller_internals = true
cattr_accessor :view_controller_internals
# Protected instance variable cache
@@protected_variables_cache = nil
cattr_accessor :protected_variables_cache
# Prepends all the URL-generating helpers from AssetHelper. This makes it possible to easily move javascripts, stylesheets,
# and images to a dedicated asset server away from the main web server. Example:
# ActionController::Base.asset_host = "http://assets.example.com"
@@asset_host = ""
cattr_accessor :asset_host
# All requests are considered local by default, so everyone will be exposed to detailed debugging screens on errors.
# When the application is ready to go public, this should be set to false, and the protected method local_request?
# should instead be implemented in the controller to determine when debugging screens should be shown.
@@consider_all_requests_local = true
cattr_accessor :consider_all_requests_local
# Enable or disable the collection of failure information for RoutingErrors.
# This information can be extremely useful when tweaking custom routes, but is
# pointless once routes have been tested and verified.
@@debug_routes = true
cattr_accessor :debug_routes
# Controls whether the application is thread-safe, so multi-threaded servers like WEBrick know whether to apply a mutex
# around the performance of each action. Action Pack and Active Record are by default thread-safe, but many applications
# may not be. Turned off by default.
@@allow_concurrency = false
cattr_accessor :allow_concurrency
# Modern REST web services often need to submit complex data to the web application.
# The param_parsers hash lets you register handlers wich will process the http body and add parameters to the
# params hash. These handlers are invoked for post and put requests.
#
# By default application/xml is enabled. A XmlSimple class with the same param name as the root will be instanciated
# in the params. This allows XML requests to mask themselves as regular form submissions, so you can have one
# action serve both regular forms and web service requests.
#
# Example of doing your own parser for a custom content type:
#
# ActionController::Base.param_parsers[Mime::Type.lookup('application/atom+xml')] = Proc.new do |data|
# node = REXML::Document.new(post)
# { node.root.name => node.root }
# end
#
# Note: Up until release 1.1 of Rails, Action Controller would default to using XmlSimple configured to discard the
# root node for such requests. The new default is to keep the root, such that "
Good seeing you!
" using Builder # render :inline => "xml.p { 'Good seeing you!' }", :type => :rxml # # # Renders "hello david" # render :inline => "<%= 'hello ' + name %>", :locals => { :name => "david" } # # _Deprecation_ _notice_: This used to have the signature render_template(template, status = 200, type = :rhtml) # # === Rendering inline JavaScriptGenerator page updates # # In addition to rendering JavaScriptGenerator page updates with Ajax in RJS templates (see ActionView::Base for details), # you can also pass the :update parameter to +render+, along with a block, to render page updates inline. # # render :update do |page| # page.replace_html 'user_list', :partial => 'user', :collection => @users # page.visual_effect :highlight, 'user_list' # end # # === Rendering nothing # # Rendering nothing is often convenient in combination with Ajax calls that perform their effect client-side or # when you just want to communicate a status code. Due to a bug in Safari, nothing actually means a single space. # # # Renders an empty response with status code 200 # render :nothing => true # # # Renders an empty response with status code 401 (access denied) # render :nothing => true, :status => 401 def render(options = nil, deprecated_status = nil, &block) #:doc: raise DoubleRenderError, "Can only render or redirect once per action" if performed? # Backwards compatibility unless options.is_a?(Hash) if options == :update options = {:update => true} else return render_file(options || default_template_name, deprecated_status, true) end end if content_type = options[:content_type] headers["Content-Type"] = content_type.to_s end if text = options[:text] render_text(text, options[:status]) else if file = options[:file] render_file(file, options[:status], options[:use_full_path], options[:locals] || {}) elsif template = options[:template] render_file(template, options[:status], true) elsif inline = options[:inline] render_template(inline, options[:status], options[:type], options[:locals] || {}) elsif action_name = options[:action] render_action(action_name, options[:status], options[:layout]) elsif xml = options[:xml] render_xml(xml, options[:status]) elsif partial = options[:partial] partial = default_template_name if partial == true if collection = options[:collection] render_partial_collection(partial, collection, options[:spacer_template], options[:locals], options[:status]) else render_partial(partial, ActionView::Base::ObjectWrapper.new(options[:object]), options[:locals], options[:status]) end elsif options[:update] add_variables_to_assigns @template.send :evaluate_assigns generator = ActionView::Helpers::PrototypeHelper::JavaScriptGenerator.new(@template, &block) render_javascript(generator.to_s) elsif options[:nothing] # Safari doesn't pass the headers of the return if the response is zero length render_text(" ", options[:status]) else render_file(default_template_name, options[:status], true) end end end # Renders according to the same rules as render, but returns the result in a string instead # of sending it as the response body to the browser. def render_to_string(options = nil, &block) #:doc: result = render(options, &block) erase_render_results forget_variables_added_to_assigns reset_variables_added_to_assigns result end def render_action(action_name, status = nil, with_layout = true) #:nodoc: template = default_template_name(action_name.to_s) if with_layout && !template_exempt_from_layout?(template) render_with_layout(template, status) else render_without_layout(template, status) end end def render_file(template_path, status = nil, use_full_path = false, locals = {}) #:nodoc: add_variables_to_assigns assert_existence_of_template_file(template_path) if use_full_path logger.info("Rendering #{template_path}" + (status ? " (#{status})" : '')) if logger render_text(@template.render_file(template_path, use_full_path, locals), status) end def render_template(template, status = nil, type = :rhtml, local_assigns = {}) #:nodoc: add_variables_to_assigns render_text(@template.render_template(type, template, nil, local_assigns), status) end def render_text(text = nil, status = nil) #:nodoc: @performed_render = true @response.headers['Status'] = (status || DEFAULT_RENDER_STATUS_CODE).to_s @response.body = text end def render_javascript(javascript, status = nil) #:nodoc: @response.headers['Content-Type'] = 'text/javascript; charset=UTF-8' render_text(javascript, status) end def render_xml(xml, status = nil) #:nodoc: @response.headers['Content-Type'] = 'application/xml' render_text(xml, status) end def render_nothing(status = nil) #:nodoc: render_text(' ', status) end def render_partial(partial_path = default_template_name, object = nil, local_assigns = nil, status = nil) #:nodoc: add_variables_to_assigns render_text(@template.render_partial(partial_path, object, local_assigns), status) end def render_partial_collection(partial_name, collection, partial_spacer_template = nil, local_assigns = nil, status = nil) #:nodoc: add_variables_to_assigns render_text(@template.render_partial_collection(partial_name, collection, partial_spacer_template, local_assigns), status) end def render_with_layout(template_name = default_template_name, status = nil, layout = nil) #:nodoc: render_with_a_layout(template_name, status, layout) end def render_without_layout(template_name = default_template_name, status = nil) #:nodoc: render_with_no_layout(template_name, status) end # Clears the rendered results, allowing for another render to be performed. def erase_render_results #:nodoc: @response.body = nil @performed_render = false end # Clears the redirected results from the headers, resets the status to 200 and returns # the URL that was used to redirect or nil if there was no redirected URL # Note that +redirect_to+ will change the body of the response to indicate a redirection. # The response body is not reset here, see +erase_render_results+ def erase_redirect_results #:nodoc: @performed_redirect = false response.redirected_to = nil response.redirected_to_method_params = nil response.headers['Status'] = DEFAULT_RENDER_STATUS_CODE response.headers.delete('location') end # Erase both render and redirect results def erase_results #:nodoc: erase_render_results erase_redirect_results end def rewrite_options(options) #:nodoc: if defaults = default_url_options(options) defaults.merge(options) else options end end # Overwrite to implement a number of default options that all url_for-based methods will use. The default options should come in # the form of a hash, just like the one you would use for url_for directly. Example: # # def default_url_options(options) # { :project => @project.active? ? @project.url_name : "unknown" } # end # # As you can infer from the example, this is mostly useful for situations where you want to centralize dynamic decisions about the # urls as they stem from the business domain. Please note that any individual url_for call can always override the defaults set # by this method. def default_url_options(options) #:doc: end # Redirects the browser to the target specified in +options+. This parameter can take one of three forms: # # * Hash: The URL will be generated by calling url_for with the +options+. # * String starting with protocol:// (like http://): Is passed straight through as the target for redirection. # * String not containing a protocol: The current protocol and host is prepended to the string. # * :back: Back to the page that issued the request. Useful for forms that are triggered from multiple places. # Short-hand for redirect_to(request.env["HTTP_REFERER"]) # # Examples: # redirect_to :action => "show", :id => 5 # redirect_to "http://www.rubyonrails.org" # redirect_to "/images/screenshot.jpg" # redirect_to :back # # The redirection happens as a "302 Moved" header. # # When using redirect_to :back, if there is no referrer, # RedirectBackError will be raised. You may specify some fallback # behavior for this case by rescueing RedirectBackError. def redirect_to(options = {}, *parameters_for_method_reference) #:doc: case options when %r{^\w+://.*} raise DoubleRenderError if performed? logger.info("Redirected to #{options}") if logger response.redirect(options) response.redirected_to = options @performed_redirect = true when String redirect_to(request.protocol + request.host_with_port + options) when :back request.env["HTTP_REFERER"] ? redirect_to(request.env["HTTP_REFERER"]) : raise(RedirectBackError) else if parameters_for_method_reference.empty? redirect_to(url_for(options)) response.redirected_to = options else redirect_to(url_for(options, *parameters_for_method_reference)) response.redirected_to, response.redirected_to_method_params = options, parameters_for_method_reference end end end # Sets a HTTP 1.1 Cache-Control header. Defaults to issuing a "private" instruction, so that # intermediate caches shouldn't cache the response. # # Examples: # expires_in 20.minutes # expires_in 3.hours, :private => false # expires in 3.hours, 'max-stale' => 5.hours, :private => nil, :public => true # # This method will overwrite an existing Cache-Control header. # See http://www.w3.org/Protocols/rfc2616/rfc2616-sec14.html for more possibilities. def expires_in(seconds, options = {}) #:doc: cache_options = { 'max-age' => seconds, 'private' => true }.symbolize_keys.merge!(options.symbolize_keys) cache_options.delete_if { |k,v| v.nil? or v == false } cache_control = cache_options.map{ |k,v| v == true ? k.to_s : "#{k.to_s}=#{v.to_s}"} @response.headers["Cache-Control"] = cache_control.join(', ') end # Sets a HTTP 1.1 Cache-Control header of "no-cache" so no caching should occur by the browser or # intermediate caches (like caching proxy servers). def expires_now #:doc: @response.headers["Cache-Control"] = "no-cache" end # Resets the session by clearing out all the objects stored within and initializing a new session object. def reset_session #:doc: @request.reset_session @session = @request.session @response.session = @session end private def self.view_class @view_class ||= # create a new class based on the default template class and include helper methods returning Class.new(ActionView::Base) do |view_class| view_class.send(:include, master_helper_module) end end def self.view_root @view_root ||= template_root end def initialize_template_class(response) raise "You must assign a template class through ActionController.template_class= before processing a request" unless @@template_class response.template = self.class.view_class.new(self.class.view_root, {}, self) response.redirected_to = nil @performed_render = @performed_redirect = false end def assign_shortcuts(request, response) @request, @params, @cookies = request, request.parameters, request.cookies @response = response @response.session = request.session @session = @response.session @template = @response.template @assigns = @response.template.assigns @headers = @response.headers end def initialize_current_url @url = UrlRewriter.new(@request, @params.clone()) end def log_processing if logger logger.info "\n\nProcessing #{controller_class_name}\##{action_name} (for #{request_origin}) [#{request.method.to_s.upcase}]" logger.info " Session ID: #{@session.session_id}" if @session and @session.respond_to?(:session_id) logger.info " Parameters: #{respond_to?(:filter_parameters) ? filter_parameters(@params).inspect : @params.inspect}" end end def perform_action if self.class.action_methods.include?(action_name) || self.class.action_methods.include?('method_missing') send(action_name) render unless performed? elsif template_exists? && template_public? render else raise UnknownAction, "No action responded to #{action_name}", caller end end def performed? @performed_render || @performed_redirect end def assign_names @action_name = (params['action'] || 'index') end def action_methods self.class.action_methods end def self.action_methods @action_methods ||= Set.new(public_instance_methods - hidden_actions) end def add_variables_to_assigns unless @variables_added add_instance_variables_to_assigns add_class_variables_to_assigns if view_controller_internals @variables_added = true end end def forget_variables_added_to_assigns @variables_added = nil end def reset_variables_added_to_assigns @template.instance_variable_set("@assigns_added", nil) end def add_instance_variables_to_assigns @@protected_variables_cache ||= protected_instance_variables.inject({}) { |h, k| h[k] = true; h } instance_variables.each do |var| next if @@protected_variables_cache.include?(var) @assigns[var[1..-1]] = instance_variable_get(var) end end def add_class_variables_to_assigns %w( template_root logger template_class ignore_missing_templates ).each do |cvar| @assigns[cvar] = self.send(cvar) end end def protected_instance_variables if view_controller_internals [ "@assigns", "@performed_redirect", "@performed_render" ] else [ "@assigns", "@performed_redirect", "@performed_render", "@request", "@response", "@session", "@cookies", "@template", "@request_origin", "@parent_controller" ] end end def request_origin # this *needs* to be cached! # otherwise you'd get different results if calling it more than once @request_origin ||= "#{@request.remote_ip} at #{Time.now.to_s(:db)}" end def complete_request_uri "#{@request.protocol}#{@request.host}#{@request.request_uri}" end def close_session @session.close unless @session.nil? || Hash === @session end def template_exists?(template_name = default_template_name) @template.file_exists?(template_name) end def template_public?(template_name = default_template_name) @template.file_public?(template_name) end def template_exempt_from_layout?(template_name = default_template_name) template_name =~ /\.rjs$/ || (@template.pick_template_extension(template_name) == :rjs rescue false) end def assert_existence_of_template_file(template_name) unless template_exists?(template_name) || ignore_missing_templates full_template_path = @template.send(:full_template_path, template_name, 'rhtml') template_type = (template_name =~ /layouts/i) ? 'layout' : 'template' raise(MissingTemplate, "Missing #{template_type} #{full_template_path}") end end def default_template_name(action_name = self.action_name) if action_name action_name = action_name.to_s if action_name.include?('/') && template_path_includes_controller?(action_name) action_name = strip_out_controller(action_name) end end "#{self.class.controller_path}/#{action_name}" end def strip_out_controller(path) path.split('/', 2).last end def template_path_includes_controller?(path) self.class.controller_path.split('/')[-1] == path.split('/')[0] end def process_cleanup close_session end end end