require 'active_support/core_ext/module/attr_internal' require 'active_support/core_ext/module/delegation' require 'active_support/core_ext/class/attribute' require 'active_support/ordered_options' require 'action_view/log_subscriber' module ActionView #:nodoc: # = Action View Base # # Action View templates can be written in several ways. If the template file has a .erb extension then it uses a mixture of ERb # (included in Ruby) and HTML. If the template file has a .builder extension then Jim Weirich's Builder::XmlMarkup library is used. # # == ERB # # You trigger ERB by using embeddings such as <% %>, <% -%>, and <%= %>. The <%= %> tag set is used when you want output. Consider the # following loop for names: # # Names of all the people # <% @people.each do |person| %> # Name: <%= person.name %>
# <% end %> # # The loop is setup in regular embedding tags <% %> and the name is written using the output embedding tag <%= %>. Note that this # is not just a usage suggestion. Regular output functions like print or puts won't work with ERB templates. So this would be wrong: # # <%# WRONG %> # Hi, Mr. <% puts "Frodo" %> # # If you absolutely must write from within a function use +concat+. # # <%- and -%> suppress leading and trailing whitespace, including the trailing newline, and can be used interchangeably with <% and %>. # # === Using sub templates # # Using sub templates allows you to sidestep tedious replication and extract common display structures in shared templates. The # classic example is the use of a header and footer (even though the Action Pack-way would be to use Layouts): # # <%= render "shared/header" %> # Something really specific and terrific # <%= render "shared/footer" %> # # As you see, we use the output embeddings for the render methods. The render call itself will just return a string holding the # result of the rendering. The output embedding writes it to the current template. # # But you don't have to restrict yourself to static includes. Templates can share variables amongst themselves by using instance # variables defined using the regular embedding tags. Like this: # # <% @page_title = "A Wonderful Hello" %> # <%= render "shared/header" %> # # Now the header can pick up on the @page_title variable and use it for outputting a title tag: # # <%= @page_title %> # # === Passing local variables to sub templates # # You can pass local variables to sub templates by using a hash with the variable names as keys and the objects as values: # # <%= render "shared/header", { :headline => "Welcome", :person => person } %> # # These can now be accessed in shared/header with: # # Headline: <%= headline %> # First name: <%= person.first_name %> # # If you need to find out whether a certain local variable has been assigned a value in a particular render call, # you need to use the following pattern: # # <% if local_assigns.has_key? :headline %> # Headline: <%= headline %> # <% end %> # # Testing using defined? headline will not work. This is an implementation restriction. # # === Template caching # # By default, Rails will compile each template to a method in order to render it. When you alter a template, # Rails will check the file's modification time and recompile it in development mode. # # == Builder # # Builder templates are a more programmatic alternative to ERB. They are especially useful for generating XML content. An XmlMarkup object # named +xml+ is automatically made available to templates with a .builder extension. # # Here are some basic examples: # # xml.em("emphasized") # => emphasized # xml.em { xml.b("emph & bold") } # => emph & bold # xml.a("A Link", "href" => "http://onestepback.org") # => A Link # xml.target("name" => "compile", "option" => "fast") # => # # NOTE: order of attributes is not specified. # # Any method with a block will be treated as an XML markup tag with nested markup in the block. For example, the following: # # xml.div do # xml.h1(@person.name) # xml.p(@person.bio) # end # # would produce something like: # #
#

David Heinemeier Hansson

#

A product of Danish Design during the Winter of '79...

#
# # A full-length RSS example actually used on Basecamp: # # xml.rss("version" => "2.0", "xmlns:dc" => "http://purl.org/dc/elements/1.1/") do # xml.channel do # xml.title(@feed_title) # xml.link(@url) # xml.description "Basecamp: Recent items" # xml.language "en-us" # xml.ttl "40" # # @recent_items.each do |item| # xml.item do # xml.title(item_title(item)) # xml.description(item_description(item)) if item_description(item) # xml.pubDate(item_pubDate(item)) # xml.guid(@person.firm.account.url + @recent_items.url(item)) # xml.link(@person.firm.account.url + @recent_items.url(item)) # # xml.tag!("dc:creator", item.author_name) if item_has_creator?(item) # end # end # end # end # # More builder documentation can be found at http://builder.rubyforge.org. class Base include Helpers, ::ERB::Util, Context # Specify the proc used to decorate input tags that refer to attributes with errors. cattr_accessor :field_error_proc @@field_error_proc = Proc.new{ |html_tag, instance| "
#{html_tag}
".html_safe } # How to complete the streaming when an exception occurs. # This is our best guess: first try to close the attribute, then the tag. cattr_accessor :streaming_completion_on_exception @@streaming_completion_on_exception = %(">) class_attribute :helpers class_attribute :_routes class_attribute :logger class << self delegate :erb_trim_mode=, :to => 'ActionView::Template::Handlers::ERB' delegate :logger, :to => 'ActionController::Base', :allow_nil => true def cache_template_loading ActionView::Resolver.caching? end def cache_template_loading=(value) ActionView::Resolver.caching = value end def xss_safe? #:nodoc: true end # This method receives routes and helpers from the controller # and return a subclass ready to be used as view context. def prepare(routes, helpers) #:nodoc: Class.new(self) do if routes include routes.url_helpers include routes.mounted_helpers end if helpers include helpers self.helpers = helpers end end end end attr_accessor :view_renderer attr_internal :config, :assigns delegate :lookup_context, :to => :view_renderer delegate :formats, :formats=, :locale, :locale=, :view_paths, :view_paths=, :to => :lookup_context def assign(new_assigns) # :nodoc: @_assigns = new_assigns.each { |key, value| instance_variable_set("@#{key}", value) } end def initialize(context = nil, assigns = {}, controller = nil, formats = nil) #:nodoc: @_config = ActiveSupport::InheritableOptions.new # Handle all these for backwards compatibility. # TODO Provide a new API for AV::Base and deprecate this one. if context.is_a?(ActionView::Renderer) @view_renderer = context elsif lookup_context = context.is_a?(ActionView::LookupContext) ? context : ActionView::LookupContext.new(context) lookup_context.formats = formats if formats lookup_context.prefixes = controller._prefixes if controller @view_renderer = ActionView::Renderer.new(lookup_context) end assign(assigns) assign_controller(controller) _prepare_context end ActiveSupport.run_load_hooks(:action_view, self) end end