require 'action_controller/request'
require 'action_controller/response'
require 'action_controller/routing'
require 'action_controller/code_generation'
require 'action_controller/url_rewriter'
require 'drb'
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 DoubleRenderError < ActionControllerError #:nodoc:
end
# Action Controllers are made up of one or more actions that performs its purpose and then either renders a template or
# redirects 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 a mod_rewrite mapping. 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
#
# GuestBookController.template_root = "templates/"
# GuestBookController.process_cgi
#
# All actions assume that you want to render a template matching the name of the action at the end of the performance
# unless you tell it otherwise. The index action complies with this assumption, so after populating the @entries instance
# variable, the GuestBookController will render "templates/guestbook/index.rhtml".
#
# Unlike index, the sign action isn't interested in rendering a template. So after performing its main purpose (creating a
# new entry in the guest book), it sheds the rendering assumption and 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.
#
# Also note that it's the final call to process_cgi that actually initiates the action performance. It will extract
# request and response objects from the CGI
#
# == 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 in @request and is primarily used to query for http headers. These queries are made by
# accessing the environment hash, like this:
#
# def hello_ip
# location = @request.env["REMOTE_IP"]
# render_text "Hello stranger from #{location}"
# end
#
# == Parameters
#
# All request parameters whether they come from a GET or POST request, or from the URL, are available through the @params hash.
# So 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 memory 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 hash:
#
# @session[:person] = Person.authenticate(user_name, password)
#
# And retrieved again through the same hash:
#
# Hello #{@session[:person]}
#
# 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 memory overhead. In other words, think carefully about size and caching before resorting to the use
# of the session.
#
# If you store a model in the session, you must also include a line like:
#
# model :person
#
# For that particular controller. In Rails, you can also just add it in your app/controller/application.rb file (so the model is available
# for all controllers). This lets Action Pack know to have the model definition loaded before retrieving the object from the session.
#
# 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.
#
# == 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, so it's normally nothing you'll need to be concerned about.
#
# == 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 "weblog/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
#
# Redirecting is what actions that update the model do when they're done. The save_post method shouldn't be responsible for also
# showing the post once it's saved -- that's the job for show_post. So once save_post has completed its business, it'll
# redirect to show_post. All redirects are external, which means that when the user refreshes his browser, it's not going to save
# the post again, but rather just show it one more time.
#
# This sounds fairly simple, but the redirection is complicated by the quest for a phenomenon known as "pretty urls". Instead of accepting
# the dreadful beings that is "weblog_controller?action=show&post_id=5", Action Controller goes out of its way to represent the former as
# "/weblog/show/5". And this is even the simple case. As an example of a more advanced pretty url consider
# "/library/books/ISBN/0743536703/show", which can be mapped to books_controller?action=show&type=ISBN&id=0743536703.
#
# Redirects work by rewriting the URL of the current action. So if the show action was called by "/library/books/ISBN/0743536703/show",
# we can redirect to an edit action simply by doing redirect_to(:action => "edit"), which could throw the user to
# "/library/books/ISBN/0743536703/edit". Naturally, you'll need to setup the routes configuration file to point to the proper controller
# and action in the first place, but once you have, it can be rewritten with ease.
#
# Let's consider a bunch of examples on how to go from "/clients/37signals/basecamp/project/dash" to somewhere else:
#
# redirect_to(:action => "edit") =>
# /clients/37signals/basecamp/project/dash
#
# redirect_to(:client_name => "nextangle", :project_name => "rails") =>
# /clients/nextangle/rails/project/dash
#
# Those redirects happen under the configuration of:
#
# map.connect 'clients/:client_name/:project_name/:controller/:action'
#
# == Calling multiple redirects or renders
#
# The rule for handling calls of multiple redirects and renders is that the first call wins. So in the following example:
#
# def do_something
# redirect_to :action => "elsewhere"
# render_action "overthere"
# end
#
# Only the redirect happens. The rendering call is simply ignored.
#
# == Environments
#
# Action Controller works out of the box with CGI, FastCGI, and mod_ruby. CGI and mod_ruby controllers are triggered just the same using:
#
# WeblogController.process_cgi
#
# FastCGI controllers are triggered using:
#
# FCGI.each_cgi{ |cgi| WeblogController.process_cgi(cgi) }
class Base
include ClassInheritableAttributes
DEFAULT_RENDER_STATUS_CODE = "200 OK"
# 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
# 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 knows 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
# Template root determines the base from which template references will be made. So a call to render("test/template")
# will be converted to "#{template_root}/test/template.rhtml".
class_inheritable_accessor :template_root
# The logger is used for generating information on the action run-time (including benchmarking) if available.
# Can be set to nil for no logging. Compatible with both Ruby's own Logger and Log4r loggers.
cattr_accessor :logger
# Determines which template class should be used by ActionController.
cattr_accessor :template_class
# Turn on +ignore_missing_templates+ if you want to unit test actions without making the associated templates.
cattr_accessor :ignore_missing_templates
# Holds the request object that's primarily used to get environment variables through access like
# request.env["REQUEST_URI"].
attr_accessor :request
# Holds a hash of all the GET, POST, and Url parameters passed to the action. Accessed like @params["post_id"]
# to get the post_id. No type casts are made, so all values are returned as strings.
attr_accessor :params
# Holds the response object that's primarily used to set additional HTTP headers through access like
# response.headers["Cache-Control"] = "no-cache". Can also be used to access the final body HTML after a template
# has been rendered through response.body -- useful for after_filters that wants to manipulate the output,
# such as a OutputCompressionFilter.
attr_accessor :response
# Holds a hash of objects in the session. Accessed like session[:person] to get the object tied to the "person"
# key. The session will hold any type of object as values, but the key should be a string.
attr_accessor :session
# Holds a hash of header names and values. Accessed like headers["Cache-Control"] to get the value of the Cache-Control
# directive. Values should always be specified as strings.
attr_accessor :headers
# Holds the hash of variables that are passed on to the template class to be made available to the view. This hash
# is generated by taking a snapshot of all the instance variables in the current scope just before a template is rendered.
attr_accessor :assigns
# Returns the name of the action this controller is processing.
attr_accessor :action_name
class << self
# Factory for the standard create, process loop where the controller is discarded after processing.
def process(request, response) #:nodoc:
new.process(request, response)
end
# Converts the class name from something like "OneModule::TwoModule::NeatController" to "NeatController".
def controller_class_name
Inflector.demodulize(name)
end
# Converts the class name from something like "OneModule::TwoModule::NeatController" to "neat".
def controller_name
Inflector.underscore(controller_class_name.sub(/Controller/, ""))
end
# Convert the class name from something like "OneModule::TwoModule::NeatController" to "one_module/two_module/neat".
def controller_path
components = self.name.to_s.split('::').collect { |name| name.underscore }
components[-1] = $1 if /^(.*)_controller$/ =~ components[-1]
components.shift if components.first == 'controllers' # Transitional conditional to accomodate root Controllers module
components.join('/')
end
# Return an array containing the names of public methods that have been marked hidden from the action processor.
# By default, all methods defined in ActionController::Base and included modules are hidden.
# More methods can be hidden using +hide_actions+.
def hidden_actions
write_inheritable_attribute(:hidden_actions, ActionController::Base.public_instance_methods) unless read_inheritable_attribute(:hidden_actions)
read_inheritable_attribute(:hidden_actions)
end
# Hide each of the given methods from being callable as actions.
def hide_action(*names)
write_inheritable_attribute(:hidden_actions, hidden_actions | names.collect {|n| n.to_s})
end
# Set the template root to be one directory behind the root dir of the controller. Examples:
# /code/weblog/components/admin/users_controller.rb with Admin::UsersController
# will use /code/weblog/components as template root
# and find templates in /code/weblog/components/admin/users/
#
# /code/weblog/components/admin/parties/users_controller.rb with Admin::Parties::UsersController
# will also use /code/weblog/components as template root
# and find templates in /code/weblog/components/admin/parties/users/
def uses_component_template_root
path_of_calling_controller = File.dirname(caller[0].split(/:\d+:/).first)
path_of_controller_root = path_of_calling_controller.sub(/#{controller_path.split("/")[0..-2]}$/, "")
self.template_root = path_of_controller_root
end
# Temporary method for enabling upload progress until it's ready to leave experimental mode
def enable_upload_progress # :nodoc:
require 'action_controller/upload_progress'
include ActionController::UploadProgress
end
end
public
# Extracts the action_name from the request parameters and performs that action.
def process(request, response, method = :perform_action, *arguments) #:nodoc:
initialize_template_class(response)
assign_shortcuts(request, response)
initialize_current_url
@action_name = params[:action] || 'index'
log_processing unless logger.nil?
send(method, *arguments)
close_session
return @response
end
# Returns a URL that has been rewritten according to the options hash and the defined Routes.
# (For doing a complete redirect, use redirect_to).
#
# url_for is used to:
#
# All keys given to url_for are forwarded to the Route module save for the following:
# * :anchor -- specifies the anchor name to be appended to the path. For example,
# url_for :controller => 'posts', :action => 'show', :id => 10, :anchor => 'comments'
# will produce "/posts/show/10#comments".
# * :only_path -- if true, returns the absolute URL (omitting the protocol, host name, and port)
# * :trailing_slash -- if true, adds a trailing slash, as in "/archive/2005/". Note that this
# is currently not recommended since it breaks caching.
# * :host -- overrides the default (current) host if provided
# * :protocol -- overrides the default (current) protocol if provided
#
# The URL is generated from the remaining keys in the hash. A URL contains two key parts: the and a query string.
# Routes composes a query string as the key/value pairs not included in the .
#
# The default Routes setup supports a typical Rails path of "controller/action/id" where action and id are optional, with
# action defaulting to 'index' when not given. Here are some typical url_for statements and their corresponding URLs:
#
# url_for :controller => 'posts', :action => 'recent' # => 'proto://host.com/posts/recent'
# url_for :controller => 'posts', :action => 'index' # => 'proto://host.com/posts'
# url_for :controller => 'posts', :action => 'show', :id => 10 # => 'proto://host.com/posts/show/10'
#
# When generating a new URL, missing values may be filled in from the current request's parameters. For example,
# url_for :action => 'some_action' will retain the current controller, as expected. This behavior extends to
# other parameters, including :controller, :id, and any other parameters that are placed into a Route's
# path.
#
# The URL helpers such as url_for have a limited form of memory: when generating a new URL, they can look for
# missing values in the current request's parameters. Routes attempts to guess when a value should and should not be
# taken from the defaults. There are a few simple rules on how this is performed:
#
# * If the controller name begins with a slash, no defaults are used: url_for :controller => '/home'
# * If the controller changes, the action will default to index unless provided
#
# The final rule is applied while the URL is being generated and is best illustrated by an example. Let us consider the
# route given by map.connect 'people/:last/:first/:action', :action => 'bio', :controller => 'people'.
#
# Suppose that the current URL is "people/hh/david/contacts". Let's consider a few different cases URLs which are generated
# from this page.
#
# * url_for :action => 'bio' -- During the generation of this URL, default values will be used for the first and
# last components, and the action shall change. The generated URL will be, "people/hh/david/bio".
# * url_for :first => 'davids-little-brother' This generates the URL 'people/hh/davids-little-brother' -- note
# that this URL leaves out the assumed action of 'bio'.
#
# However, you might ask why the action from the current request, 'contacts', isn't carried over into the new URL. The
# answer has to do with the order in which the parameters appear in the generated path. In a nutshell, since the
# value that appears in the slot for :first is not equal to default value for :first we stop using
# defaults. On it's own, this rule can account for much of the typical Rails URL behavior.
#
# Although a convienence, defaults can occasionaly get in your way. In some cases a default persists longer than desired.
# The default may be cleared by adding :name => nil to url_for's options.
# This is often required when writing form helpers, since the defaults in play may vary greatly depending upon where the
# helper is used from. The following line will redirect to PostController's default action, regardless of the page it is
# displayed on:
#
# url_for :controller => 'posts', :action => nil
#
# Instead of passing an options hash, you can also pass a method reference in the form of a symbol. Consider this example:
#
# class WeblogController < ActionController::Base
# def update
# # do some update
# redirect_to :dashboard_url
# end
#
# protected
# def dashboard_url
# url_for :controller => (@project.active? ? "project" : "account"), :action => "dashboard"
# end
# end
def url_for(options = {}, *parameters_for_method_reference) #:doc:
case options
when String then options
when Symbol then send(options, *parameters_for_method_reference)
when Hash then @url.rewrite(rewrite_options(options))
end
end
# Converts the class name from something like "OneModule::TwoModule::NeatController" to "NeatController".
def controller_class_name
self.class.controller_class_name
end
# Converts the class name from something like "OneModule::TwoModule::NeatController" to "neat".
def controller_name
self.class.controller_name
end
protected
# Renders the template specified by template_name, which defaults to the name of the current controller and action.
# So calling +render+ in WeblogController#show will attempt to render "#{template_root}/weblog/show.rhtml" or
# "#{template_root}/weblog/show.rxml" (in that order). The template_root is set on the ActionController::Base class and is
# shared by all controllers. It's also possible to pass a status code using the second parameter. This defaults to "200 OK",
# but can be changed, such as by calling render("weblog/error", "500 Error").
# A unified replacement for the individual renders (work-in-progress).
def render(options = {}, deprecated_status = nil)
# puts "Rendering: #{options.inspect}"
raise DoubleRenderError, "Can only render or redirect once per action" if performed?
# Backwards compatibility
return render({ :template => options || default_template_name, :status => deprecated_status }) if !options.is_a?(Hash)
add_variables_to_assigns
options[:status] = (options[:status] || DEFAULT_RENDER_STATUS_CODE).to_s
if options[:text]
@response.headers["Status"] = options[:status]
@response.body = options[:text]
@performed_render = true
return options[:text]
elsif options[:file]
assert_existance_of_template_file(options[:file]) if options[:use_full_path]
logger.info("Rendering #{options[:file]} (#{options[:status]})") unless logger.nil?
render(options.merge({ :text => @template.render_file(options[:file], options[:use_full_path])}))
elsif options[:template]
render(options.merge({ :file => options[:template], :use_full_path => true }))
elsif options[:inline]
render(options.merge({
:text =>
@template.render_template(
options[:type] || :rhtml,
options[:inline],
options[:locals] || {}
)
}))
elsif options[:action]
render(options.merge({ :template => default_template_name(options[:action]) }))
elsif options[:partial] && options[:collection]
render(options.merge({
:text => (
@template.render_partial_collection(
options[:partial] == true ? default_template_name : options[:partial],
options[:collection], options[:spacer_template],
options[:locals] || {}
) || ''
)
}))
elsif options[:partial]
render(options.merge({ :text => @template.render_partial(
options[:partial] == true ? default_template_name : options[:partial],
options[:object], options[:locals] || {}
) }))
elsif options[:nothing]
render(options.merge({ :text => "" }))
else
render(options.merge({ :action => action_name }))
end
end
# Returns the result of the render as a string.
def render_to_string(options = {}) #:doc:
result = render(options)
erase_render_results
return result
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, resetting 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
def rewrite_options(options)
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 current protocol and host is prepended to the string.
#
# Examples:
# redirect_to :action => "show", :id => 5
# redirect_to "http://www.rubyonrails.org"
# redirect_to "/images/screenshot.jpg"
#
# The redirection happens as a "302 Moved" header.
def redirect_to(options = {}, *parameters_for_method_reference) #:doc:
case options
when %r{^\w+://.*}
raise DoubleRenderError, "Can only render or redirect once per action" if performed?
logger.info("Redirected to #{options}") unless logger.nil?
response.redirect(options)
response.redirected_to = options
@performed_redirect = true
when String
redirect_to(request.protocol + request.host_with_port + options)
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
# 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 initialize_template_class(response)
begin
response.template = template_class.new(template_root, {}, self)
rescue
raise "You must assign a template class through ActionController.template_class= before processing a request"
end
@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
logger.info "\n\nProcessing #{controller_class_name}\##{action_name} (for #{request_origin})"
logger.info " Parameters: #{@params.inspect}"
end
def perform_action
if action_methods.include?(action_name) || 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 action_methods
@action_methods ||= (self.class.public_instance_methods - self.class.hidden_actions)
end
def add_variables_to_assigns
add_instance_variables_to_assigns
add_class_variables_to_assigns if view_controller_internals
end
def add_instance_variables_to_assigns
protected_variables_cache = protected_instance_variables
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" ]
end
end
def request_origin
"#{@request.remote_ip} at #{Time.now.to_s}"
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 assert_existance_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(default_action_name = action_name)
"#{self.class.controller_path}/#{default_action_name}"
end
end
end