module ActionView #:nodoc: class ActionViewError < StandardError #:nodoc: end class MissingTemplate < ActionViewError #:nodoc: attr_reader :path def initialize(paths, path, template_format = nil) @path = path full_template_path = path.include?('.') ? path : "#{path}.erb" display_paths = paths.compact.join(":") template_type = (path =~ /layouts/i) ? 'layout' : 'template' super("Missing #{template_type} #{full_template_path} in view path #{display_paths}") end end # Action View templates can be written in three ways. If the template file has a .erb (or .rhtml) extension then it uses a mixture of ERb # (included in Ruby) and HTML. If the template file has a .builder (or .rxml) extension then Jim Weirich's Builder::XmlMarkup library is used. # If the template file has a .rjs extension then it will use ActionView::Helpers::PrototypeHelper::JavaScriptGenerator. # # = 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 # <% for person in @people %> # 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: # # Hi, Mr. <% puts "Frodo" %> # # If you absolutely must write from within a function, you can use the TextHelper#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. # # == 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 { # xml.h1(@person.name) # xml.p(@person.bio) # } # # 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" # # for item in @recent_items # 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. # # == JavaScriptGenerator # # JavaScriptGenerator templates end in .rjs. Unlike conventional templates which are used to # render the results of an action, these templates generate instructions on how to modify an already rendered page. This makes it easy to # modify multiple elements on your page in one declarative Ajax response. Actions with these templates are called in the background with Ajax # and make updates to the page where the request originated from. # # An instance of the JavaScriptGenerator object named +page+ is automatically made available to your template, which is implicitly wrapped in an ActionView::Helpers::PrototypeHelper#update_page block. # # When an .rjs action is called with +link_to_remote+, the generated JavaScript is automatically evaluated. Example: # # link_to_remote :url => {:action => 'delete'} # # The subsequently rendered delete.rjs might look like: # # page.replace_html 'sidebar', :partial => 'sidebar' # page.remove "person-#{@person.id}" # page.visual_effect :highlight, 'user-list' # # This refreshes the sidebar, removes a person element and highlights the user list. # # See the ActionView::Helpers::PrototypeHelper::GeneratorMethods documentation for more details. class Base include Helpers, Partials, ::ERB::Util extend ActiveSupport::Memoizable attr_accessor :base_path, :assigns, :template_extension attr_accessor :controller attr_writer :template_format attr_accessor :output_buffer class << self delegate :erb_trim_mode=, :to => 'ActionView::TemplateHandlers::ERB' delegate :logger, :to => 'ActionController::Base' end @@debug_rjs = false ## # :singleton-method: # Specify whether RJS responses should be wrapped in a try/catch block # that alert()s the caught exception (and then re-raises it). cattr_accessor :debug_rjs # Specify whether templates should be cached. Otherwise the file we be read everytime it is accessed. # Automatically reloading templates are not thread safe and should only be used in development mode. @@cache_template_loading = nil cattr_accessor :cache_template_loading def self.cache_template_loading? ActionController::Base.allow_concurrency || (cache_template_loading.nil? ? !ActiveSupport::Dependencies.load? : cache_template_loading) end attr_internal :request delegate :request_forgery_protection_token, :template, :params, :session, :cookies, :response, :headers, :flash, :logger, :action_name, :controller_name, :to => :controller module CompiledTemplates #:nodoc: # holds compiled template code end include CompiledTemplates def self.process_view_paths(value) ActionView::PathSet.new(Array(value)) end attr_reader :helpers class ProxyModule < Module def initialize(receiver) @receiver = receiver end def include(*args) super(*args) @receiver.extend(*args) end end def initialize(view_paths = [], assigns_for_first_render = {}, controller = nil)#:nodoc: @assigns = assigns_for_first_render @assigns_added = nil @_render_stack = [] @controller = controller @helpers = ProxyModule.new(self) self.view_paths = view_paths end attr_reader :view_paths def view_paths=(paths) @view_paths = self.class.process_view_paths(paths) # we might be using ReloadableTemplates, so we need to let them know this a new request @view_paths.load! end # Returns the result of a render that's dictated by the options hash. The primary options are: # # * :partial - See ActionView::Partials. # * :update - Calls update_page with the block given. # * :file - Renders an explicit template file (this used to be the old default), add :locals to pass in those. # * :inline - Renders an inline template similar to how it's done in the controller. # * :text - Renders the text passed in out. # # If no options hash is passed or :update specified, the default is to render a partial and use the second parameter # as the locals hash. def render(options = {}, local_assigns = {}, &block) #:nodoc: local_assigns ||= {} case options when Hash options = options.reverse_merge(:locals => {}) if options[:layout] _render_with_layout(options, local_assigns, &block) elsif options[:file] template = self.view_paths.find_template(options[:file], template_format) template.render_template(self, options[:locals]) elsif options[:partial] render_partial(options) elsif options[:inline] InlineTemplate.new(options[:inline], options[:type]).render(self, options[:locals]) elsif options[:text] options[:text] end when :update update_page(&block) else render_partial(:partial => options, :locals => local_assigns) end end # The format to be used when choosing between multiple templates with # the same name but differing formats. See +Request#template_format+ # for more details. def template_format if defined? @template_format @template_format elsif controller && controller.respond_to?(:request) @template_format = controller.request.template_format.to_sym else @template_format = :html end end # Access the current template being rendered. # Returns a ActionView::Template object. def template @_render_stack.last end private # Evaluates the local assigns and controller ivars, pushes them to the view. def _evaluate_assigns_and_ivars #:nodoc: unless @assigns_added @assigns.each { |key, value| instance_variable_set("@#{key}", value) } _copy_ivars_from_controller @assigns_added = true end end def _copy_ivars_from_controller #:nodoc: if @controller variables = @controller.instance_variable_names variables -= @controller.protected_instance_variables if @controller.respond_to?(:protected_instance_variables) variables.each { |name| instance_variable_set(name, @controller.instance_variable_get(name)) } end end def _set_controller_content_type(content_type) #:nodoc: if controller.respond_to?(:response) controller.response.content_type ||= content_type end end def _render_with_layout(options, local_assigns, &block) #:nodoc: partial_layout = options.delete(:layout) if block_given? begin @_proc_for_layout = block concat(render(options.merge(:partial => partial_layout))) ensure @_proc_for_layout = nil end else begin original_content_for_layout = @content_for_layout if defined?(@content_for_layout) @content_for_layout = render(options) if (options[:inline] || options[:file] || options[:text]) @cached_content_for_layout = @content_for_layout render(:file => partial_layout, :locals => local_assigns) else render(options.merge(:partial => partial_layout)) end ensure @content_for_layout = original_content_for_layout end end end end end