Class: ActionController::Base
- Includes:
- StatusCodes
- Defined in:
- lib/action_controller/base.rb,
lib/action_controller/cgi_process.rb,
lib/action_controller/test_process.rb
Overview
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.erb
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:
<input type="text" name="post[name]" value="david">
<input type="text" name="post[address]" value="hyacintvej">
A request stemming from a form holding these inputs will include { "post" => { "name" => "david", "address" => "hyacintvej" } }
. If the address input had been named “post[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
:
# removes :person from session
session[:person] = nil
or you can remove the entire session with reset_session
.
Sessions are stored by default in a browser cookie that’s cryptographically signed, but unencrypted. This prevents the user from tampering with the session but also allows him to see its contents.
Do not put secret information in cookie-based sessions!
Other options for session storage are:
-
ActiveRecordStore - Sessions are stored in your database, which works better than PStore with multiple app servers and, unlike CookieStore, hides your session contents from the user. To use ActiveRecordStore, set
config.action_controller.session_store = :active_record_store
in your
config/environment.rb
and runrake db:sessions:create
. -
MemCacheStore - Sessions are stored as entries in your memcached cache. Set the session store type in
config/environment.rb
:config.action_controller.session_store = :mem_cache_store
This assumes that memcached has been installed and configured properly. See the MemCacheStore docs for more information.
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 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 may contain only a single render or a single 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
Direct Known Subclasses
Constant Summary collapse
- DEFAULT_RENDER_STATUS_CODE =
"200 OK"
- @@protected_view_variables =
Controller specific instance variables which will not be accessible inside views.
%w(@assigns @performed_redirect @performed_render @variables_added @request_origin @url @parent_controller @action_name @before_filter_chain_aborted @action_cache_path @_session @_cookies @_headers @_params @_flash @_response)
- @@asset_host =
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"
""
- @@consider_all_requests_local =
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. true
- @@debug_routes =
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.
true
- @@allow_concurrency =
Indicates to Mongrel or Webrick whether to allow concurrent action processing. Your controller actions and any other code they call must also behave well when called from concurrent threads. Turned off by default.
false
- @@param_parsers =
Modern REST web services often need to submit complex data to the web application. The
@@param_parsers
hash lets you register handlers which will process the HTTP body and add parameters to theparams
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 instantiated in theparams
. 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 “<r><name>David</name></r>” results in
params[:r][:name]
for “David” instead ofparams[:name]
. To get the old behavior, you can re-register XmlSimple as application/xml handler ike this:ActionController::Base.param_parsers[Mime::XML] = Proc.new { |data| XmlSimple.xml_in(data, 'ForceArray' => false) }
A YAML parser is also available and can be turned on with:
ActionController::Base.param_parsers[Mime::YAML] = :yaml
{ Mime::MULTIPART_FORM => :multipart_form, Mime::URL_ENCODED_FORM => :url_encoded_form, Mime::XML => :xml_simple, Mime::JSON => :json }
- @@default_charset =
Controls the default charset for all renders.
"utf-8"
- @@resource_action_separator =
Controls the resource action separator
"/"
- @@resources_path_names =
Allow to override path names for default resources’ actions
{ :new => 'new', :edit => 'edit' }
- @@exempt_from_layout =
Templates that are exempt from layouts
Set.new([/\.js\.erb$/])
Constants included from StatusCodes
StatusCodes::STATUS_CODES, StatusCodes::SYMBOL_TO_STATUS_CODE
Instance Attribute Summary collapse
-
#action_name ⇒ Object
Returns the name of the action this controller is processing.
-
#assigns ⇒ Object
Holds the hash of variables that are passed on to the template class to be made available to the view.
Class Method Summary collapse
-
.append_view_path(path) ⇒ Object
Adds a view_path to the end of the view_paths array.
-
.controller_class_name ⇒ Object
Converts the class name from something like “OneModule::TwoModule::NeatController” to “NeatController”.
-
.controller_name ⇒ Object
Converts the class name from something like “OneModule::TwoModule::NeatController” to “neat”.
-
.controller_path ⇒ Object
Converts the class name from something like “OneModule::TwoModule::NeatController” to “one_module/two_module/neat”.
-
.exempt_from_layout(*extensions) ⇒ Object
Don’t render layouts for templates with the given extensions.
-
.filter_parameter_logging(*filter_words, &block) ⇒ Object
Replace sensitive parameter data from the request log.
-
.hidden_actions ⇒ Object
Return an array containing the names of public methods that have been marked hidden from the action processor.
-
.hide_action(*names) ⇒ Object
Hide each of the given methods from being callable as actions.
-
.prepend_view_path(path) ⇒ Object
Adds a view_path to the front of the view_paths array.
-
.process(request, response) ⇒ Object
Factory for the standard create, process loop where the controller is discarded after processing.
-
.process_cgi(cgi = CGI.new, session_options = {}) ⇒ Object
Process a request extracted from a CGI object and return a response.
-
.process_test(request) ⇒ Object
Process a test request called with a TestRequest object.
-
.view_paths ⇒ Object
View load paths determine the bases from which template references can be made.
- .view_paths=(value) ⇒ Object
Instance Method Summary collapse
-
#append_view_path(path) ⇒ Object
Adds a view_path to the end of the view_paths array.
-
#controller_class_name ⇒ Object
Converts the class name from something like “OneModule::TwoModule::NeatController” to “NeatController”.
-
#controller_name ⇒ Object
Converts the class name from something like “OneModule::TwoModule::NeatController” to “neat”.
-
#controller_path ⇒ Object
Converts the class name from something like “OneModule::TwoModule::NeatController” to “one_module/two_module/neat”.
-
#prepend_view_path(path) ⇒ Object
Adds a view_path to the front of the view_paths array.
-
#process(request, response, method = :perform_action, *arguments) ⇒ Object
Extracts the action_name from the request parameters and performs that action.
-
#process_cgi(cgi, session_options = {}) ⇒ Object
:nodoc:.
-
#process_test(request) ⇒ Object
:nodoc:.
- #process_with_test(*args) ⇒ Object
- #session_enabled? ⇒ Boolean
-
#url_for(options = {}) ⇒ Object
Returns a URL that has been rewritten according to the options hash and the defined Routes.
-
#view_paths ⇒ Object
View load paths for controller.
- #view_paths=(value) ⇒ Object
Instance Attribute Details
#action_name ⇒ Object
Returns the name of the action this controller is processing.
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# File 'lib/action_controller/base.rb', line 381 def action_name @action_name end |
#assigns ⇒ Object
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.
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# File 'lib/action_controller/base.rb', line 378 def assigns @assigns end |
Class Method Details
.append_view_path(path) ⇒ Object
Adds a view_path to the end of the view_paths array. If the current class has no view paths, copy them from the superclass. This change will be visible for all future requests.
ArticleController.append_view_path("views/default")
ArticleController.append_view_path(["views/default", "views/custom"])
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# File 'lib/action_controller/base.rb', line 455 def append_view_path(path) @view_paths = superclass.view_paths.dup if @view_paths.nil? view_paths.push(*path) ActionView::TemplateFinder.process_view_paths(path) end |
.controller_class_name ⇒ Object
Converts the class name from something like “OneModule::TwoModule::NeatController” to “NeatController”.
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# File 'lib/action_controller/base.rb', line 393 def controller_class_name @controller_class_name ||= name.demodulize end |
.controller_name ⇒ Object
Converts the class name from something like “OneModule::TwoModule::NeatController” to “neat”.
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# File 'lib/action_controller/base.rb', line 398 def controller_name @controller_name ||= controller_class_name.sub(/Controller$/, '').underscore end |
.controller_path ⇒ Object
Converts the class name from something like “OneModule::TwoModule::NeatController” to “one_module/two_module/neat”.
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# File 'lib/action_controller/base.rb', line 403 def controller_path @controller_path ||= name.gsub(/Controller$/, '').underscore end |
.exempt_from_layout(*extensions) ⇒ Object
Don’t render layouts for templates with the given extensions.
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# File 'lib/action_controller/base.rb', line 511 def exempt_from_layout(*extensions) regexps = extensions.collect do |extension| extension.is_a?(Regexp) ? extension : /\.#{Regexp.escape(extension.to_s)}$/ end @@exempt_from_layout.merge regexps end |
.filter_parameter_logging(*filter_words, &block) ⇒ Object
Replace sensitive parameter data from the request log. Filters parameters that have any of the arguments as a substring. Looks in all subhashes of the param hash for keys to filter. If a block is given, each key and value of the parameter hash and all subhashes is passed to it, the value or key can be replaced using String#replace or similar method.
Examples:
filter_parameter_logging
=> Does nothing, just slows the logging process down
filter_parameter_logging :password
=> replaces the value to all keys matching /password/i with "[FILTERED]"
filter_parameter_logging :foo, "bar"
=> replaces the value to all keys matching /foo|bar/i with "[FILTERED]"
filter_parameter_logging { |k,v| v.reverse! if k =~ /secret/i }
=> reverses the value to all keys matching /secret/i
filter_parameter_logging(:foo, "bar") { |k,v| v.reverse! if k =~ /secret/i }
=> reverses the value to all keys matching /secret/i, and
replaces the value to all keys matching /foo|bar/i with "[FILTERED]"
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# File 'lib/action_controller/base.rb', line 484 def filter_parameter_logging(*filter_words, &block) parameter_filter = Regexp.new(filter_words.collect{ |s| s.to_s }.join('|'), true) if filter_words.length > 0 define_method(:filter_parameters) do |unfiltered_parameters| filtered_parameters = {} unfiltered_parameters.each do |key, value| if key =~ parameter_filter filtered_parameters[key] = '[FILTERED]' elsif value.is_a?(Hash) filtered_parameters[key] = filter_parameters(value) elsif block_given? key = key.dup value = value.dup if value yield key, value filtered_parameters[key] = value else filtered_parameters[key] = value end end filtered_parameters end protected :filter_parameters end |
.hidden_actions ⇒ Object
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
.
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# File 'lib/action_controller/base.rb', line 410 def hidden_actions unless read_inheritable_attribute(:hidden_actions) write_inheritable_attribute(:hidden_actions, ActionController::Base.public_instance_methods.map(&:to_s)) end read_inheritable_attribute(:hidden_actions) end |
.hide_action(*names) ⇒ Object
Hide each of the given methods from being callable as actions.
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# File 'lib/action_controller/base.rb', line 419 def hide_action(*names) write_inheritable_attribute(:hidden_actions, hidden_actions | names.map(&:to_s)) end |
.prepend_view_path(path) ⇒ Object
Adds a view_path to the front of the view_paths array. If the current class has no view paths, copy them from the superclass. This change will be visible for all future requests.
ArticleController.prepend_view_path("views/default")
ArticleController.prepend_view_path(["views/default", "views/custom"])
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# File 'lib/action_controller/base.rb', line 442 def prepend_view_path(path) @view_paths = superclass.view_paths.dup if @view_paths.nil? view_paths.unshift(*path) ActionView::TemplateFinder.process_view_paths(path) end |
.process(request, response) ⇒ Object
Factory for the standard create, process loop where the controller is discarded after processing.
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# File 'lib/action_controller/base.rb', line 388 def process(request, response) #:nodoc: new.process(request, response) end |
.process_cgi(cgi = CGI.new, session_options = {}) ⇒ Object
Process a request extracted from a CGI object and return a response. Pass false as session_options
to disable sessions (large performance increase if sessions are not needed). The session_options
are the same as for CGI::Session:
-
:database_manager
- standard options are CGI::Session::FileStore, CGI::Session::MemoryStore, and CGI::Session::PStore (default). Additionally, there is CGI::Session::DRbStore and CGI::Session::ActiveRecordStore. Read more about these in lib/action_controller/session. -
:session_key
- the parameter name used for the session id. Defaults to ‘_session_id’. -
:session_id
- the session id to use. If not provided, then it is retrieved from thesession_key
cookie, or automatically generated for a new session. -
:new_session
- if true, force creation of a new session. If not set, a new session is only created if none currently exists. If false, a new session is never created, and if none currently exists and thesession_id
option is not set, an ArgumentError is raised. -
:session_expires
- the time the current session expires, as a Time object. If not set, the session will continue indefinitely. -
:session_domain
- the hostname domain for which this session is valid. If not set, defaults to the hostname of the server. -
:session_secure
- iftrue
, this session will only work over HTTPS. -
:session_path
- the path for which this session applies. Defaults to the directory of the CGI script. -
:cookie_only
- iftrue
(the default), session IDs will only be accepted from cookies and not from the query string or POST parameters. This protects against session fixation attacks.
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# File 'lib/action_controller/cgi_process.rb', line 26 def self.process_cgi(cgi = CGI.new, = {}) new.process_cgi(cgi, ) end |
.process_test(request) ⇒ Object
Process a test request called with a TestRequest object.
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# File 'lib/action_controller/test_process.rb', line 7 def self.process_test(request) new.process_test(request) end |
.view_paths ⇒ Object
View load paths determine the bases from which template references can be made. So a call to render(“test/template”) will be looked up in the view load paths array and the closest match will be returned.
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# File 'lib/action_controller/base.rb', line 426 def view_paths @view_paths || superclass.view_paths end |
.view_paths=(value) ⇒ Object
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# File 'lib/action_controller/base.rb', line 430 def view_paths=(value) @view_paths = value ActionView::TemplateFinder.process_view_paths(value) end |
Instance Method Details
#append_view_path(path) ⇒ Object
Adds a view_path to the end of the view_paths array. This change affects the current request only.
self.append_view_path("views/default")
self.append_view_path(["views/default", "views/custom"])
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# File 'lib/action_controller/base.rb', line 674 def append_view_path(path) @template.finder.append_view_path(path) # Mutex needed end |
#controller_class_name ⇒ Object
Converts the class name from something like “OneModule::TwoModule::NeatController” to “NeatController”.
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# File 'lib/action_controller/base.rb', line 629 def controller_class_name self.class.controller_class_name end |
#controller_name ⇒ Object
Converts the class name from something like “OneModule::TwoModule::NeatController” to “neat”.
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# File 'lib/action_controller/base.rb', line 634 def controller_name self.class.controller_name end |
#controller_path ⇒ Object
Converts the class name from something like “OneModule::TwoModule::NeatController” to “one_module/two_module/neat”.
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# File 'lib/action_controller/base.rb', line 639 def controller_path self.class.controller_path end |
#prepend_view_path(path) ⇒ Object
Adds a view_path to the front of the view_paths array. This change affects the current request only.
self.prepend_view_path("views/default")
self.prepend_view_path(["views/default", "views/custom"])
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# File 'lib/action_controller/base.rb', line 664 def prepend_view_path(path) @template.finder.prepend_view_path(path) # Mutex needed end |
#process(request, response, method = :perform_action, *arguments) ⇒ Object
Extracts the action_name from the request parameters and performs that action.
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# File 'lib/action_controller/base.rb', line 521 def process(request, response, method = :perform_action, *arguments) #:nodoc: initialize_template_class(response) assign_shortcuts(request, response) initialize_current_url assign_names forget_variables_added_to_assigns log_processing send(method, *arguments) assign_default_content_type_and_charset response.request = request response.prepare! unless component_request? response ensure process_cleanup end |
#process_cgi(cgi, session_options = {}) ⇒ Object
:nodoc:
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# File 'lib/action_controller/cgi_process.rb', line 30 def process_cgi(cgi, = {}) #:nodoc: process(CgiRequest.new(cgi, ), CgiResponse.new(cgi)).out end |
#process_test(request) ⇒ Object
:nodoc:
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# File 'lib/action_controller/test_process.rb', line 11 def process_test(request) #:nodoc: process(request, TestResponse.new) end |
#process_with_test(*args) ⇒ Object
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# File 'lib/action_controller/test_process.rb', line 15 def process_with_test(*args) returning process_without_test(*args) do add_variables_to_assigns end end |
#session_enabled? ⇒ Boolean
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# File 'lib/action_controller/base.rb', line 643 def session_enabled? request. && request.[:disabled] != false end |
#url_for(options = {}) ⇒ Object
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 relative URL (omitting the protocol, host name, and port) (false
by default). -
: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. -
:port
- Optionally specify the port to connect to. -
:user
- Inline HTTP authentication (only plucked out if:password
is also present). -
:password
- Inline HTTP authentication (only plucked out if:user
is also present). -
:skip_relative_url_root
- If true, the url is not constructed using therelative_url_root
of the request so the path will include the web server relative installation directory.
The URL is generated from the remaining keys in the hash. A URL contains two key parts: the <base> and a query string. Routes composes a query string as the key/value pairs not included in the <base>.
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 => 'index', :port=>'8033' # => 'proto://host.com:8033/posts'
url_for :controller => 'posts', :action => 'show', :id => 10 # => 'proto://host.com/posts/show/10'
url_for :controller => 'posts', :user => 'd', :password => '123' # => 'proto://d:[email protected]/posts'
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 of 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 its own, this rule can account for much of the typical Rails URL behavior. Although a convenience, defaults can occasionally 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
If you explicitly want to create a URL that’s almost the same as the current URL, you can do so using the :overwrite_params
options. Say for your posts you have different views for showing and printing them. Then, in the show view, you get the URL for the print view like this
url_for :overwrite_params => { :action => 'print' }
This takes the current URL as is and only exchanges the action. In contrast, url_for :action => 'print'
would have slashed-off the path components after the changed action.
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# File 'lib/action_controller/base.rb', line 616 def url_for( = {}) ||= {} case when String when Hash @url.rewrite(()) else polymorphic_url() end end |
#view_paths ⇒ Object
View load paths for controller.
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# File 'lib/action_controller/base.rb', line 650 def view_paths @template.finder.view_paths end |
#view_paths=(value) ⇒ Object
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# File 'lib/action_controller/base.rb', line 654 def view_paths=(value) @template.finder.view_paths = value # Mutex needed end |