module ActionView
module Rendering
# 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 = {}, locals = {}, &block) #:nodoc:
case options
when String, NilClass
_render_partial(:partial => options, :locals => locals || {})
when Hash
layout = options[:layout]
if block_given?
return concat(_render_partial(options.merge(:partial => layout), &block))
elsif options.key?(:partial)
return _render_partial(options)
end
layout = find(layout, {:formats => formats}) if layout
if file = options[:file]
template = find(file, {:formats => formats})
_render_template(template, layout, :locals => options[:locals] || {})
elsif inline = options[:inline]
_render_inline(inline, layout, options)
elsif text = options[:text]
_render_text(text, layout, options)
end
when :update
update_page(&block)
end
end
def _render_content(content, layout, locals)
return content unless layout
locals ||= {}
if controller && layout
@_layout = layout.identifier
logger.info("Rendering template within #{layout.identifier}") if logger
end
begin
old_content, @_content_for[:layout] = @_content_for[:layout], content
@cached_content_for_layout = @_content_for[:layout]
_render_single_template(layout, locals)
ensure
@_content_for[:layout] = old_content
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
# <html><% yield %></html>
#
# 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 <html>Content</html>.
#
# 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
# <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 in the layout would be passed into the block. The result
# would be <html>Hello David</html>.
def _layout_for(names, &block)
with_output_buffer do
# This is due to the potentially ambiguous use of yield when
# a block is passed in to a template *and* there is a content_for()
# of the same name. Suggested solution: require explicit use of content_for
# in these ambiguous cases.
#
# We would be able to continue supporting yield in all non-ambiguous
# cases. Question: should we deprecate yield in favor of content_for
# and reserve yield for cases where there is a yield into a real block?
if @_content_for.key?(names.first) || !block_given?
return @_content_for[names.first || :layout]
else
return yield(names)
end
end
end
def _render_single_template(template, locals = {}, &block)
with_template(template) do
template.render(self, locals) do |*names|
_layout_for(names, &block)
end
end
rescue Exception => e
if e.is_a?(TemplateError)
e.sub_template_of(template)
raise e
else
raise TemplateError.new(template, assigns, e)
end
end
def _render_inline(inline, layout, options)
handler = Template.handler_class_for_extension(options[:type] || "erb")
template = Template.new(options[:inline], "inline #{options[:inline].inspect}", handler, {})
content = _render_single_template(template, options[:locals] || {})
layout ? _render_content(content, layout, options[:locals]) : content
end
def _render_text(text, layout, options)
layout ? _render_content(text, layout, options[:locals]) : text
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
# _partial:: true if the template is a partial
def render_template(options)
@assigns_added = nil
template, layout, partial = options.values_at(:_template, :_layout, :_partial)
_render_template(template, layout, options, partial)
end
def _render_template(template, layout = nil, options = {}, partial = nil)
logger && logger.info do
msg = "Rendering #{template.identifier}"
msg << " (#{options[:status]})" if options[:status]
msg
end
locals = options[:locals] || {}
content = if partial
_render_partial_object(template, options)
else
_render_single_template(template, locals)
end
_render_content(content, layout, locals)
end
end
end
