diff options
Diffstat (limited to 'actionpack/lib/action_view/renderer')
5 files changed, 419 insertions, 68 deletions
diff --git a/actionpack/lib/action_view/renderer/abstract_renderer.rb b/actionpack/lib/action_view/renderer/abstract_renderer.rb index 4a52b3172e..60c527beeb 100644 --- a/actionpack/lib/action_view/renderer/abstract_renderer.rb +++ b/actionpack/lib/action_view/renderer/abstract_renderer.rb @@ -3,9 +3,8 @@ module ActionView delegate :find_template, :template_exists?, :with_fallbacks, :update_details, :with_layout_format, :formats, :freeze_formats, :to => :@lookup_context - def initialize(view) - @view = view - @lookup_context = view.lookup_context + def initialize(lookup_context) + @lookup_context = lookup_context end def render diff --git a/actionpack/lib/action_view/renderer/partial_renderer.rb b/actionpack/lib/action_view/renderer/partial_renderer.rb index 94c0a8a8fb..a351fbc04f 100644 --- a/actionpack/lib/action_view/renderer/partial_renderer.rb +++ b/actionpack/lib/action_view/renderer/partial_renderer.rb @@ -1,46 +1,230 @@ -require 'action_view/renderer/abstract_renderer' +require 'active_support/core_ext/object/blank' module ActionView + # = Action View Partials + # + # There's also a convenience method for rendering sub templates within the current controller that depends on a + # single object (we call this kind of sub templates for partials). It relies on the fact that partials should + # follow the naming convention of being prefixed with an underscore -- as to separate them from regular + # templates that could be rendered on their own. + # + # In a template for Advertiser#account: + # + # <%= render :partial => "account" %> + # + # This would render "advertiser/_account.html.erb" and pass the instance variable @account in as a local variable + # +account+ to the template for display. + # + # In another template for Advertiser#buy, we could have: + # + # <%= render :partial => "account", :locals => { :account => @buyer } %> + # + # <% @advertisements.each do |ad| %> + # <%= render :partial => "ad", :locals => { :ad => ad } %> + # <% end %> + # + # This would first render "advertiser/_account.html.erb" with @buyer passed in as the local variable +account+, then + # render "advertiser/_ad.html.erb" and pass the local variable +ad+ to the template for display. + # + # == The :as and :object options + # + # By default <tt>ActionView::Partials::PartialRenderer</tt> has its object in a local variable with the same + # name as the template. So, given + # + # <%= render :partial => "contract" %> + # + # within contract we'll get <tt>@contract</tt> in the local variable +contract+, as if we had written + # + # <%= render :partial => "contract", :locals => { :contract => @contract } %> + # + # With the <tt>:as</tt> option we can specify a different name for said local variable. For example, if we + # wanted it to be +agreement+ instead of +contract+ we'd do: + # + # <%= render :partial => "contract", :as => 'agreement' %> + # + # The <tt>:object</tt> option can be used to directly specify which object is rendered into the partial; + # useful when the template's object is elsewhere, in a different ivar or in a local variable for instance. + # + # Revisiting a previous example we could have written this code: + # + # <%= render :partial => "account", :object => @buyer %> + # + # <% @advertisements.each do |ad| %> + # <%= render :partial => "ad", :object => ad %> + # <% end %> + # + # The <tt>:object</tt> and <tt>:as</tt> options can be used together. + # + # == Rendering a collection of partials + # + # The example of partial use describes a familiar pattern where a template needs to iterate over an array and + # render a sub template for each of the elements. This pattern has been implemented as a single method that + # accepts an array and renders a partial by the same name as the elements contained within. So the three-lined + # example in "Using partials" can be rewritten with a single line: + # + # <%= render :partial => "ad", :collection => @advertisements %> + # + # This will render "advertiser/_ad.html.erb" and pass the local variable +ad+ to the template for display. An + # iteration counter will automatically be made available to the template with a name of the form + # +partial_name_counter+. In the case of the example above, the template would be fed +ad_counter+. + # + # The <tt>:as</tt> option may be used when rendering partials. + # + # You can specify a partial to be rendered between elements via the <tt>:spacer_template</tt> option. + # The following example will render <tt>advertiser/_ad_divider.html.erb</tt> between each ad partial: + # + # <%= render :partial => "ad", :collection => @advertisements, :spacer_template => "ad_divider" %> + # + # If the given <tt>:collection</tt> is nil or empty, <tt>render</tt> will return nil. This will allow you + # to specify a text which will displayed instead by using this form: + # + # <%= render(:partial => "ad", :collection => @advertisements) || "There's no ad to be displayed" %> + # + # NOTE: Due to backwards compatibility concerns, the collection can't be one of hashes. Normally you'd also + # just keep domain objects, like Active Records, in there. + # + # == Rendering shared partials + # + # Two controllers can share a set of partials and render them like this: + # + # <%= render :partial => "advertisement/ad", :locals => { :ad => @advertisement } %> + # + # This will render the partial "advertisement/_ad.html.erb" regardless of which controller this is being called from. + # + # == Rendering objects with the RecordIdentifier + # + # Instead of explicitly naming the location of a partial, you can also let the RecordIdentifier do the work if + # you're following its conventions for RecordIdentifier#partial_path. Examples: + # + # # @account is an Account instance, so it uses the RecordIdentifier to replace + # # <%= render :partial => "accounts/account", :locals => { :account => @account} %> + # <%= render :partial => @account %> + # + # # @posts is an array of Post instances, so it uses the RecordIdentifier to replace + # # <%= render :partial => "posts/post", :collection => @posts %> + # <%= render :partial => @posts %> + # + # == Rendering the default case + # + # If you're not going to be using any of the options like collections or layouts, you can also use the short-hand + # defaults of render to render partials. Examples: + # + # # Instead of <%= render :partial => "account" %> + # <%= render "account" %> + # + # # Instead of <%= render :partial => "account", :locals => { :account => @buyer } %> + # <%= render "account", :account => @buyer %> + # + # # @account is an Account instance, so it uses the RecordIdentifier to replace + # # <%= render :partial => "accounts/account", :locals => { :account => @account } %> + # <%= render(@account) %> + # + # # @posts is an array of Post instances, so it uses the RecordIdentifier to replace + # # <%= render :partial => "posts/post", :collection => @posts %> + # <%= render(@posts) %> + # + # == Rendering partials with layouts + # + # Partials can have their own layouts applied to them. These layouts are different than the ones that are + # specified globally for the entire action, but they work in a similar fashion. Imagine a list with two types + # of users: + # + # <%# app/views/users/index.html.erb &> + # Here's the administrator: + # <%= render :partial => "user", :layout => "administrator", :locals => { :user => administrator } %> + # + # Here's the editor: + # <%= render :partial => "user", :layout => "editor", :locals => { :user => editor } %> + # + # <%# app/views/users/_user.html.erb &> + # Name: <%= user.name %> + # + # <%# app/views/users/_administrator.html.erb &> + # <div id="administrator"> + # Budget: $<%= user.budget %> + # <%= yield %> + # </div> + # + # <%# app/views/users/_editor.html.erb &> + # <div id="editor"> + # Deadline: <%= user.deadline %> + # <%= yield %> + # </div> + # + # ...this will return: + # + # Here's the administrator: + # <div id="administrator"> + # Budget: $<%= user.budget %> + # Name: <%= user.name %> + # </div> + # + # Here's the editor: + # <div id="editor"> + # Deadline: <%= user.deadline %> + # Name: <%= user.name %> + # </div> + # + # You can also apply a layout to a block within any template: + # + # <%# app/views/users/_chief.html.erb &> + # <%= render(:layout => "administrator", :locals => { :user => chief }) do %> + # Title: <%= chief.title %> + # <% end %> + # + # ...this will return: + # + # <div id="administrator"> + # Budget: $<%= user.budget %> + # Title: <%= chief.name %> + # </div> + # + # As you can see, the <tt>:locals</tt> hash is shared between both the partial and its layout. + # + # If you pass arguments to "yield" then this will be passed to the block. One way to use this is to pass + # an array to layout and treat it as an enumerable. + # + # <%# app/views/users/_user.html.erb &> + # <div class="user"> + # Budget: $<%= user.budget %> + # <%= yield user %> + # </div> + # + # <%# app/views/users/index.html.erb &> + # <%= render :layout => @users do |user| %> + # Title: <%= user.title %> + # <% end %> + # + # This will render the layout for each user and yield to the block, passing the user, each time. + # + # You can also yield multiple times in one layout and use block arguments to differentiate the sections. + # + # <%# app/views/users/_user.html.erb &> + # <div class="user"> + # <%= yield user, :header %> + # Budget: $<%= user.budget %> + # <%= yield user, :footer %> + # </div> + # + # <%# app/views/users/index.html.erb &> + # <%= render :layout => @users do |user, section| %> + # <%- case section when :header -%> + # Title: <%= user.title %> + # <%- when :footer -%> + # Deadline: <%= user.deadline %> + # <%- end -%> + # <% end %> class PartialRenderer < AbstractRenderer #:nodoc: PARTIAL_NAMES = Hash.new {|h,k| h[k] = {} } - def initialize(view) + def initialize(*) super - @partial_names = PARTIAL_NAMES[@view.controller.class.name] + @partial_names = PARTIAL_NAMES[@lookup_context.prefixes.first] end - def setup(options, block) - partial = options[:partial] - - @options = options - @locals = options[:locals] || {} - @block = block - - if String === partial - @object = options[:object] - @path = partial - @collection = collection - else - @object = partial - - if @collection = collection_from_object || collection - paths = @collection_data = @collection.map { |o| partial_path(o) } - @path = paths.uniq.size == 1 ? paths.first : nil - else - @path = partial_path - end - end + def render(context, options, block) + setup(context, options, block) - if @path - @variable, @variable_counter = retrieve_variable(@path) - else - paths.map! { |path| retrieve_variable(path).unshift(path) } - end - - self - end - - def render wrap_formats(@path) do identifier = ((@template = find_partial) ? @template.identifier : @path) @@ -88,6 +272,38 @@ module ActionView private + def setup(context, options, block) + @view = context + partial = options[:partial] + + @options = options + @locals = options[:locals] || {} + @block = block + + if String === partial + @object = options[:object] + @path = partial + @collection = collection + else + @object = partial + + if @collection = collection_from_object || collection + paths = @collection_data = @collection.map { |o| partial_path(o) } + @path = paths.uniq.size == 1 ? paths.first : nil + else + @path = partial_path + end + end + + if @path + @variable, @variable_counter = retrieve_variable(@path) + else + paths.map! { |path| retrieve_variable(path).unshift(path) } + end + + self + end + def collection if @options.key?(:collection) collection = @options[:collection] @@ -111,7 +327,7 @@ module ActionView end def find_template(path=@path, locals=@locals.keys) - prefixes = path.include?(?/) ? [] : @view.controller_prefixes + prefixes = path.include?(?/) ? [] : @lookup_context.prefixes @lookup_context.find_template(path, prefixes, true, locals) end @@ -152,7 +368,7 @@ module ActionView object = object.to_model if object.respond_to?(:to_model) object.class.model_name.partial_path.dup.tap do |partial| - path = @view.controller_prefixes.first + path = @lookup_context.prefixes.first partial.insert(0, "#{File.dirname(path)}/") if partial.include?(?/) && path.include?(?/) end end diff --git a/actionpack/lib/action_view/renderer/renderer.rb b/actionpack/lib/action_view/renderer/renderer.rb new file mode 100644 index 0000000000..bf1b5a7d22 --- /dev/null +++ b/actionpack/lib/action_view/renderer/renderer.rb @@ -0,0 +1,54 @@ +module ActionView + # This is the main entry point for rendering. It basically delegates + # to other objects like TemplateRenderer and PartialRenderer which + # actually renders the template. + class Renderer + attr_accessor :lookup_context + + def initialize(lookup_context) + @lookup_context = lookup_context + end + + # Main render entry point shared by AV and AC. + def render(context, options) + if options.key?(:partial) + render_partial(context, options) + else + render_template(context, options) + end + end + + # Render but returns a valid Rack body. If fibers are defined, we return + # a streaming body that renders the template piece by piece. + # + # Note that partials are not supported to be rendered with streaming, + # so in such cases, we just wrap them in an array. + def render_body(context, options) + if options.key?(:partial) + [render_partial(context, options)] + else + StreamingTemplateRenderer.new(@lookup_context).render(context, options) + end + end + + # Direct accessor to template rendering. + def render_template(context, options) #:nodoc: + _template_renderer.render(context, options) + end + + # Direct access to partial rendering. + def render_partial(context, options, &block) #:nodoc: + _partial_renderer.render(context, options, block) + end + + private + + def _template_renderer #:nodoc: + @_template_renderer ||= TemplateRenderer.new(@lookup_context) + end + + def _partial_renderer #:nodoc: + @_partial_renderer ||= PartialRenderer.new(@lookup_context) + end + end +end diff --git a/actionpack/lib/action_view/renderer/streaming_template_renderer.rb b/actionpack/lib/action_view/renderer/streaming_template_renderer.rb new file mode 100644 index 0000000000..1ccf5a8ddb --- /dev/null +++ b/actionpack/lib/action_view/renderer/streaming_template_renderer.rb @@ -0,0 +1,106 @@ +# 1.9 ships with Fibers but we need to require the extra +# methods explicitly. We only load those extra methods if +# Fiber is available in the first place. +require 'fiber' if defined?(Fiber) + +module ActionView + # == TODO + # + # * Support streaming from child templates, partials and so on. + # * Integrate exceptions with exceptron + # * Rack::Cache needs to support streaming bodies + class StreamingTemplateRenderer < TemplateRenderer #:nodoc: + # A valid Rack::Body (i.e. it responds to each). + # It is initialized with a block that, when called, starts + # rendering the template. + class Body #:nodoc: + def initialize(&start) + @start = start + end + + def each(&block) + begin + @start.call(block) + rescue Exception => exception + log_error(exception) + block.call ActionView::Base.streaming_completion_on_exception + end + self + end + + private + + # This is the same logging logic as in ShowExceptions middleware. + # TODO Once "exceptron" is in, refactor this piece to simply re-use exceptron. + def log_error(exception) #:nodoc: + logger = ActionController::Base.logger + return unless logger + + message = "\n#{exception.class} (#{exception.message}):\n" + message << exception.annoted_source_code.to_s if exception.respond_to?(:annoted_source_code) + message << " " << exception.backtrace.join("\n ") + logger.fatal("#{message}\n\n") + end + end + + # For streaming, instead of rendering a given a template, we return a Body + # object that responds to each. This object is initialized with a block + # that knows how to render the template. + def render_template(template, layout_name = nil, locals = {}) #:nodoc: + return [super] unless layout_name && template.supports_streaming? + + locals ||= {} + layout = layout_name && find_layout(layout_name, locals.keys) + + Body.new do |buffer| + delayed_render(buffer, template, layout, @view, locals) + end + end + + private + + def delayed_render(buffer, template, layout, view, locals) + # Wrap the given buffer in the StreamingBuffer and pass it to the + # underlying template handler. Now, everytime something is concatenated + # to the buffer, it is not appended to an array, but streamed straight + # to the client. + output = ActionView::StreamingBuffer.new(buffer) + yielder = lambda { |*name| view._layout_for(*name) } + + instrument(:template, :identifier => template.identifier, :layout => layout.try(:virtual_path)) do + fiber = Fiber.new do + if layout + layout.render(view, locals, output, &yielder) + else + # If you don't have a layout, just render the thing + # and concatenate the final result. This is the same + # as a layout with just <%= yield %> + output.safe_concat view._layout_for + end + end + + # Set the view flow to support streaming. It will be aware + # when to stop rendering the layout because it needs to search + # something in the template and vice-versa. + view.view_flow = StreamingFlow.new(view, fiber) + + # Yo! Start the fiber! + fiber.resume + + # If the fiber is still alive, it means we need something + # from the template, so start rendering it. If not, it means + # the layout exited without requiring anything from the template. + if fiber.alive? + content = template.render(view, locals, &yielder) + + # Once rendering the template is done, sets its content in the :layout key. + view.view_flow.set(:layout, content) + + # In case the layout continues yielding, we need to resume + # the fiber until all yields are handled. + fiber.resume while fiber.alive? + end + end + end + end +end diff --git a/actionpack/lib/action_view/renderer/template_renderer.rb b/actionpack/lib/action_view/renderer/template_renderer.rb index 9ae1636131..a09cef8fef 100644 --- a/actionpack/lib/action_view/renderer/template_renderer.rb +++ b/actionpack/lib/action_view/renderer/template_renderer.rb @@ -1,41 +1,18 @@ -require 'set' require 'active_support/core_ext/object/try' require 'active_support/core_ext/array/wrap' -require 'action_view/renderer/abstract_renderer' module ActionView class TemplateRenderer < AbstractRenderer #:nodoc: - attr_reader :rendered + def render(context, options) + @view = context - def initialize(view) - super - @rendered = Set.new - end - - def render(options) wrap_formats(options[:template] || options[:file]) do template = determine_template(options) + freeze_formats(template.formats, true) render_template(template, options[:layout], options[:locals]) end end - def render_once(options) - paths, locals = options[:once], options[:locals] || {} - layout, keys = options[:layout], locals.keys - prefixes = options.fetch(:prefixes, @view.controller_prefixes) - - raise "render :once expects a String or an Array to be given" unless paths - - render_with_layout(layout, locals) do - contents = [] - Array.wrap(paths).each do |path| - template = find_template(path, prefixes, false, keys) - contents << render_template(template, nil, locals) if @rendered.add?(template) - end - contents.join("\n") - end - end - # Determine the template to be rendered using the given options. def determine_template(options) #:nodoc: keys = options[:locals].try(:keys) || [] @@ -43,7 +20,7 @@ module ActionView if options.key?(:text) Template::Text.new(options[:text], formats.try(:first)) elsif options.key?(:file) - with_fallbacks { find_template(options[:file], options[:prefixes], false, keys) } + with_fallbacks { find_template(options[:file], nil, false, keys) } elsif options.key?(:inline) handler = Template.handler_for_extension(options[:type] || "erb") Template.new(options[:inline], "inline template", handler, :locals => keys) @@ -56,7 +33,6 @@ module ActionView # Renders the given template. An string representing the layout can be # supplied as well. def render_template(template, layout_name = nil, locals = {}) #:nodoc: - freeze_formats(template.formats, true) view, locals = @view, locals || {} render_with_layout(layout_name, locals) do |layout| @@ -72,7 +48,7 @@ module ActionView if layout view = @view - view.store_content_for(:layout, content) + view.view_flow.set(:layout, content) layout.render(view, locals){ |*name| view._layout_for(*name) } else content |