+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 <tt>.erb</tt> (or <tt>.rhtml</tt>) extension then it uses a mixture of ERb
+ # (included in Ruby) and HTML. If the template file has a <tt>.builder</tt> (or <tt>.rxml</tt>) extension then Jim Weirich's Builder::XmlMarkup library is used.
+ # If the template file has a <tt>.rjs</tt> 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:
+ #
+ # <b>Names of all the people</b>
+ # <% for person in @people %>
+ # Name: <%= person.name %><br/>
+ # <% 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 <tt>@page_title</tt> variable and use it for outputting a title tag:
+ #
+ # <title><%= @page_title %></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 <tt>shared/header</tt> 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 <tt>defined? headline</tt> 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 <tt>.builder</tt> extension.
+ #
+ # Here are some basic examples:
+ #
+ # xml.em("emphasized") # => <em>emphasized</em>
+ # xml.em { xml.b("emph & bold") } # => <em><b>emph & bold</b></em>
+ # xml.a("A Link", "href"=>"http://onestepback.org") # => <a href="http://onestepback.org">A Link</a>
+ # xml.target("name"=>"compile", "option"=>"fast") # => <target option="fast" name="compile"\>
+ # # 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:
+ #
+ # <div>
+ # <h1>David Heinemeier Hansson</h1>
+ # <p>A product of Danish Design during the Winter of '79...</p>
+ # </div>
+ #
+ # 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 <tt>.rjs</tt>. 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 <tt>.rjs</tt> action is called with +link_to_remote+, the generated JavaScript is automatically evaluated. Example:
+ #
+ # link_to_remote :url => {:action => 'delete'}
+ #
+ # The subsequently rendered <tt>delete.rjs</tt> 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
+ @controller = controller
+ @helpers = ProxyModule.new(self)
+ self.view_paths = view_paths
+
+ @_first_render = nil
+ @_current_render = nil
+ 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:
+ #
+ # * <tt>:partial</tt> - See ActionView::Partials.
+ # * <tt>:update</tt> - Calls update_page with the block given.
+ # * <tt>:file</tt> - Renders an explicit template file (this used to be the old default), add :locals to pass in those.
+ # * <tt>:inline</tt> - Renders an inline template similar to how it's done in the controller.
+ # * <tt>:text</tt> - 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
+ @_current_render
+ end
+
+ def template=(template) #:nodoc:
+ @_first_render ||= template
+ @_current_render = template
+ end
+
+ def with_template(current_template)
+ last_template, self.template = template, current_template
+ yield
+ ensure
+ self.template = last_template
+ 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