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:
#
# * <tt>:partial</tt> - See <tt>ActionView::PartialRenderer</tt>.
# * <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 = {}, locals = {}, &block)
case options
when Hash
if block_given?
view_renderer.render_partial(self, options.merge(:partial => options[:layout]), &block)
else
view_renderer.render(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
# <tt>yield :some_name</tt>, the block, by default, returns <tt>content_for(:some_name)</tt>.
# If the user calls simply +yield+, the default block returns <tt>content_for(:layout)</tt>.
#
# The user can override this default by passing a block to the layout:
#
# # The template
# <%= render layout: "my_layout" do %>
# Content
# <% end %>
#
# # The layout
# <html>
# <%= yield %>
# </html>
#
# In this case, instead of the default block, which would return <tt>content_for(:layout)</tt>,
# this method returns the block that was passed in to <tt>render :layout</tt>, and the response
# would be
#
# <html>
# Content
# </html>
#
# 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
# <html>
# <%= yield Struct.new(:name).new("David") %>
# </html>
#
# In this case, the layout would receive the block passed into <tt>render :layout</tt>,
# and the struct specified would be passed into the block as an argument. The result
# would be
#
# <html>
# Hello David
# </html>
#
def _layout_for(*args, &block)
name = args.first
if block && !name.is_a?(Symbol)
capture(*args, &block)
else
super
end
end
end
end
end
