module ActionView module Helpers # = Action View Rendering # # Implements methods that allow rendering from a view context. # In order to use this module, all you need is to implement # view_renderer that returns an ActionView::Renderer object. module RenderingHelper # Returns the result of a render that's dictated by the options hash. The primary options are: # # * :partial - See ActionView::Partials. # * :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) case options when Hash if block_given? view_renderer.render_partial(self, options.merge(:partial => options[:layout]), &block) elsif options.key?(:partial) view_renderer.render_partial(self, options) else view_renderer.render_template(self, options) end else view_renderer.render_partial(self, :partial => options, :locals => locals) end end # Overwrites _layout_for in the context object so it supports the case a block is # passed to a partial. Returns the contents that are yielded to a layout, given a # name or a block. # # You can think of a layout as a method that is called with a block. If the user calls # yield :some_name, the block, by default, returns content_for(:some_name). # If the user calls simply +yield+, the default block returns content_for(:layout). # # The user can override this default by passing a block to the layout: # # # 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+: # # # 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 would be passed into the block as an argument. The result # would be # # # Hello David # # def _layout_for(*args, &block) name = args.first if block && !name.is_a?(Symbol) capture(*args, &block) else super end end end end end