require 'active_support/core_ext/object/try' module ActionView module Rendering # 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 = {}, locals = {}, &block) #:nodoc: case options when Hash layout = options[:layout] options[:locals] ||= {} if block_given? return concat(_render_partial(options.merge(:partial => layout), &block)) elsif options.key?(:partial) return _render_partial(options) end template = if options[:file] find(options[:file], {:formats => formats}) elsif options[:inline] handler = Template.handler_class_for_extension(options[:type] || "erb") Template.new(options[:inline], "inline template", handler, {}) elsif options[:text] Template::Text.new(options[:text]) end if template layout = find(layout, {:formats => formats}) if layout _render_template(template, layout, :locals => options[:locals]) end when :update update_page(&block) else _render_partial(:partial => options, :locals => locals) end end # You can think of a layout as a method that is called with a block. _layout_for # returns the contents that are yielded to the layout. If the user calls yield # :some_name, the block, by default, returns content_for(:some_name). If the user # calls yield, the default block returns content_for(:layout). # # The user can override this default by passing a block to the layout. # # ==== Example # # # The template # <% render :layout => "my_layout" do %>Content<% end %> # # # The layout # <% yield %> # # In this case, instead of the default block, which would return content_for(:layout), # this method returns the block that was passed in to render layout, and the response # would be Content. # # Finally, the block can take block arguments, which can be passed in by yield. # # ==== Example # # # The template # <% render :layout => "my_layout" do |customer| %>Hello <%= customer.name %><% end %> # # # The layout # <% yield Struct.new(:name).new("David") %> # # In this case, the layout would receive the block passed into render :layout, # and the Struct specified in the layout would be passed into the block. The result # would be Hello David. def _layout_for(name = nil, &block) return @_content_for[name || :layout] if !block_given? || name capture(&block) end # This is the API to render a ViewContext's template from a controller. # # Internal Options: # _template:: The Template object to render # _layout:: The layout, if any, to wrap the Template in def render_template(options) _evaluate_assigns_and_ivars template, layout = options.values_at(:_template, :_layout) _render_template(template, layout, options) end def _render_template(template, layout = nil, options = {}) locals = options[:locals] || {} ActiveSupport::Notifications.instrument("action_view.render_template", :identifier => template.identifier, :layout => layout.try(:identifier)) do content = template.render(self, locals) @_content_for[:layout] = content if layout @_layout = layout.identifier content = _render_layout(layout, locals) end content end end def _render_layout(layout, locals, &block) layout.render(self, locals){ |*name| _layout_for(*name, &block) } end end end