diff options
Diffstat (limited to 'actionpack/lib/abstract_controller/layouts.rb')
| -rw-r--r-- | actionpack/lib/abstract_controller/layouts.rb | 423 |
1 files changed, 0 insertions, 423 deletions
diff --git a/actionpack/lib/abstract_controller/layouts.rb b/actionpack/lib/abstract_controller/layouts.rb deleted file mode 100644 index 8e7bdf620e..0000000000 --- a/actionpack/lib/abstract_controller/layouts.rb +++ /dev/null @@ -1,423 +0,0 @@ -require "active_support/core_ext/module/remove_method" - -module AbstractController - # Layouts reverse the common pattern of including shared headers and footers in many templates to isolate changes in - # repeated setups. The inclusion pattern has pages that look like this: - # - # <%= render "shared/header" %> - # Hello World - # <%= render "shared/footer" %> - # - # This approach is a decent way of keeping common structures isolated from the changing content, but it's verbose - # and if you ever want to change the structure of these two includes, you'll have to change all the templates. - # - # With layouts, you can flip it around and have the common structure know where to insert changing content. This means - # that the header and footer are only mentioned in one place, like this: - # - # // The header part of this layout - # <%= yield %> - # // The footer part of this layout - # - # And then you have content pages that look like this: - # - # hello world - # - # At rendering time, the content page is computed and then inserted in the layout, like this: - # - # // The header part of this layout - # hello world - # // The footer part of this layout - # - # == Accessing shared variables - # - # Layouts have access to variables specified in the content pages and vice versa. This allows you to have layouts with - # references that won't materialize before rendering time: - # - # <h1><%= @page_title %></h1> - # <%= yield %> - # - # ...and content pages that fulfill these references _at_ rendering time: - # - # <% @page_title = "Welcome" %> - # Off-world colonies offers you a chance to start a new life - # - # The result after rendering is: - # - # <h1>Welcome</h1> - # Off-world colonies offers you a chance to start a new life - # - # == Layout assignment - # - # You can either specify a layout declaratively (using the #layout class method) or give - # it the same name as your controller, and place it in <tt>app/views/layouts</tt>. - # If a subclass does not have a layout specified, it inherits its layout using normal Ruby inheritance. - # - # For instance, if you have PostsController and a template named <tt>app/views/layouts/posts.html.erb</tt>, - # that template will be used for all actions in PostsController and controllers inheriting - # from PostsController. - # - # If you use a module, for instance Weblog::PostsController, you will need a template named - # <tt>app/views/layouts/weblog/posts.html.erb</tt>. - # - # Since all your controllers inherit from ApplicationController, they will use - # <tt>app/views/layouts/application.html.erb</tt> if no other layout is specified - # or provided. - # - # == Inheritance Examples - # - # class BankController < ActionController::Base - # # bank.html.erb exists - # - # class ExchangeController < BankController - # # exchange.html.erb exists - # - # class CurrencyController < BankController - # - # class InformationController < BankController - # layout "information" - # - # class TellerController < InformationController - # # teller.html.erb exists - # - # class EmployeeController < InformationController - # # employee.html.erb exists - # layout nil - # - # class VaultController < BankController - # layout :access_level_layout - # - # class TillController < BankController - # layout false - # - # In these examples, we have three implicit lookup scenarios: - # * The BankController uses the "bank" layout. - # * The ExchangeController uses the "exchange" layout. - # * The CurrencyController inherits the layout from BankController. - # - # However, when a layout is explicitly set, the explicitly set layout wins: - # * The InformationController uses the "information" layout, explicitly set. - # * The TellerController also uses the "information" layout, because the parent explicitly set it. - # * The EmployeeController uses the "employee" layout, because it set the layout to nil, resetting the parent configuration. - # * The VaultController chooses a layout dynamically by calling the <tt>access_level_layout</tt> method. - # * The TillController does not use a layout at all. - # - # == Types of layouts - # - # Layouts are basically just regular templates, but the name of this template needs not be specified statically. Sometimes - # you want to alternate layouts depending on runtime information, such as whether someone is logged in or not. This can - # be done either by specifying a method reference as a symbol or using an inline method (as a proc). - # - # The method reference is the preferred approach to variable layouts and is used like this: - # - # class WeblogController < ActionController::Base - # layout :writers_and_readers - # - # def index - # # fetching posts - # end - # - # private - # def writers_and_readers - # logged_in? ? "writer_layout" : "reader_layout" - # end - # end - # - # Now when a new request for the index action is processed, the layout will vary depending on whether the person accessing - # is logged in or not. - # - # If you want to use an inline method, such as a proc, do something like this: - # - # class WeblogController < ActionController::Base - # layout proc { |controller| controller.logged_in? ? "writer_layout" : "reader_layout" } - # end - # - # If an argument isn't given to the proc, it's evaluated in the context of - # the current controller anyway. - # - # class WeblogController < ActionController::Base - # layout proc { logged_in? ? "writer_layout" : "reader_layout" } - # end - # - # Of course, the most common way of specifying a layout is still just as a plain template name: - # - # class WeblogController < ActionController::Base - # layout "weblog_standard" - # end - # - # The template will be looked always in <tt>app/views/layouts/</tt> folder. But you can point - # <tt>layouts</tt> folder direct also. <tt>layout "layouts/demo"</tt> is the same as <tt>layout "demo"</tt>. - # - # Setting the layout to nil forces it to be looked up in the filesystem and fallbacks to the parent behavior if none exists. - # Setting it to nil is useful to re-enable template lookup overriding a previous configuration set in the parent: - # - # class ApplicationController < ActionController::Base - # layout "application" - # end - # - # class PostsController < ApplicationController - # # Will use "application" layout - # end - # - # class CommentsController < ApplicationController - # # Will search for "comments" layout and fallback "application" layout - # layout nil - # end - # - # == Conditional layouts - # - # If you have a layout that by default is applied to all the actions of a controller, you still have the option of rendering - # a given action or set of actions without a layout, or restricting a layout to only a single action or a set of actions. The - # <tt>:only</tt> and <tt>:except</tt> options can be passed to the layout call. For example: - # - # class WeblogController < ActionController::Base - # layout "weblog_standard", except: :rss - # - # # ... - # - # end - # - # This will assign "weblog_standard" as the WeblogController's layout for all actions except for the +rss+ action, which will - # be rendered directly, without wrapping a layout around the rendered view. - # - # Both the <tt>:only</tt> and <tt>:except</tt> condition can accept an arbitrary number of method references, so - # #<tt>except: [ :rss, :text_only ]</tt> is valid, as is <tt>except: :rss</tt>. - # - # == Using a different layout in the action render call - # - # If most of your actions use the same layout, it makes perfect sense to define a controller-wide layout as described above. - # Sometimes you'll have exceptions where one action wants to use a different layout than the rest of the controller. - # You can do this by passing a <tt>:layout</tt> option to the <tt>render</tt> call. For example: - # - # class WeblogController < ActionController::Base - # layout "weblog_standard" - # - # def help - # render action: "help", layout: "help" - # end - # end - # - # This will override the controller-wide "weblog_standard" layout, and will render the help action with the "help" layout instead. - module Layouts - extend ActiveSupport::Concern - - include Rendering - - included do - class_attribute :_layout, :_layout_conditions, :instance_accessor => false - self._layout = nil - self._layout_conditions = {} - _write_layout_method - end - - delegate :_layout_conditions, to: :class - - module ClassMethods - def inherited(klass) # :nodoc: - super - klass._write_layout_method - end - - # This module is mixed in if layout conditions are provided. This means - # that if no layout conditions are used, this method is not used - module LayoutConditions # :nodoc: - private - - # Determines whether the current action has a layout definition by - # checking the action name against the :only and :except conditions - # set by the <tt>layout</tt> method. - # - # ==== Returns - # * <tt> Boolean</tt> - True if the action has a layout definition, false otherwise. - def _conditional_layout? - return unless super - - conditions = _layout_conditions - - if only = conditions[:only] - only.include?(action_name) - elsif except = conditions[:except] - !except.include?(action_name) - else - true - end - end - end - - # Specify the layout to use for this class. - # - # If the specified layout is a: - # String:: the String is the template name - # Symbol:: call the method specified by the symbol, which will return the template name - # false:: There is no layout - # true:: raise an ArgumentError - # nil:: Force default layout behavior with inheritance - # - # ==== Parameters - # * <tt>layout</tt> - The layout to use. - # - # ==== Options (conditions) - # * :only - A list of actions to apply this layout to. - # * :except - Apply this layout to all actions but this one. - def layout(layout, conditions = {}) - include LayoutConditions unless conditions.empty? - - conditions.each {|k, v| conditions[k] = Array(v).map {|a| a.to_s} } - self._layout_conditions = conditions - - self._layout = layout - _write_layout_method - end - - # If no layout is supplied, look for a template named the return - # value of this method. - # - # ==== Returns - # * <tt>String</tt> - A template name - def _implied_layout_name # :nodoc: - controller_path - end - - # Creates a _layout method to be called by _default_layout . - # - # If a layout is not explicitly mentioned then look for a layout with the controller's name. - # if nothing is found then try same procedure to find super class's layout. - def _write_layout_method # :nodoc: - remove_possible_method(:_layout) - - prefixes = _implied_layout_name =~ /\blayouts/ ? [] : ["layouts"] - default_behavior = "lookup_context.find_all('#{_implied_layout_name}', #{prefixes.inspect}).first || super" - name_clause = if name - default_behavior - else - <<-RUBY - super - RUBY - end - - layout_definition = case _layout - when String - _layout.inspect - when Symbol - <<-RUBY - #{_layout}.tap do |layout| - return #{default_behavior} if layout.nil? - unless layout.is_a?(String) || !layout - raise ArgumentError, "Your layout method :#{_layout} returned \#{layout}. It " \ - "should have returned a String, false, or nil" - end - end - RUBY - when Proc - define_method :_layout_from_proc, &_layout - protected :_layout_from_proc - <<-RUBY - result = _layout_from_proc(#{_layout.arity == 0 ? '' : 'self'}) - return #{default_behavior} if result.nil? - result - RUBY - when false - nil - when true - raise ArgumentError, "Layouts must be specified as a String, Symbol, Proc, false, or nil" - when nil - name_clause - end - - self.class_eval <<-RUBY, __FILE__, __LINE__ + 1 - def _layout - if _conditional_layout? - #{layout_definition} - else - #{name_clause} - end - end - private :_layout - RUBY - end - end - - def _normalize_options(options) # :nodoc: - super - - if _include_layout?(options) - layout = options.delete(:layout) { :default } - options[:layout] = _layout_for_option(layout) - end - end - - attr_internal_writer :action_has_layout - - def initialize(*) # :nodoc: - @_action_has_layout = true - super - end - - # Controls whether an action should be rendered using a layout. - # If you want to disable any <tt>layout</tt> settings for the - # current action so that it is rendered without a layout then - # either override this method in your controller to return false - # for that action or set the <tt>action_has_layout</tt> attribute - # to false before rendering. - def action_has_layout? - @_action_has_layout - end - - private - - def _conditional_layout? - true - end - - # This will be overwritten by _write_layout_method - def _layout; end - - # Determine the layout for a given name, taking into account the name type. - # - # ==== Parameters - # * <tt>name</tt> - The name of the template - def _layout_for_option(name) - case name - when String then _normalize_layout(name) - when Proc then name - when true then Proc.new { _default_layout(true) } - when :default then Proc.new { _default_layout(false) } - when false, nil then nil - else - raise ArgumentError, - "String, Proc, :default, true, or false, expected for `layout'; you passed #{name.inspect}" - end - end - - def _normalize_layout(value) - value.is_a?(String) && value !~ /\blayouts/ ? "layouts/#{value}" : value - end - - # Returns the default layout for this controller. - # Optionally raises an exception if the layout could not be found. - # - # ==== Parameters - # * <tt>require_layout</tt> - If set to true and layout is not found, - # an ArgumentError exception is raised (defaults to false) - # - # ==== Returns - # * <tt>template</tt> - The template object for the default layout (or nil) - def _default_layout(require_layout = false) - begin - value = _layout if action_has_layout? - rescue NameError => e - raise e, "Could not render layout: #{e.message}" - end - - if require_layout && action_has_layout? && !value - raise ArgumentError, - "There was no default layout for #{self.class} in #{view_paths.inspect}" - end - - _normalize_layout(value) - end - - def _include_layout?(options) - (options.keys & [:text, :inline, :partial]).empty? || options.key?(:layout) - end - end -end |