module ActionView::Helpers::RenderingHelper
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.
Public Instance Methods
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 <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:
# 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 render
:layout, and the struct specified would be passed into the block as
an argument. The result would be
<html> Hello David </html>
# File lib/action_view/helpers/rendering_helper.rb, line 87 def _layout_for(*args, &block) name = args.first if block && !name.is_a?(Symbol) capture(*args, &block) else super end end
Returns the result of a render that's dictated by the options hash. The primary options are:
-
:partial- SeeActionView::PartialRenderer. -
: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. -
:plain- Renders the text passed in out. Setting the content type astext/plain. -
:html- Renders the HTML safe string passed in out, otherwise performs HTML escape on the string first. Setting the content type astext/html. -
:body- Renders the text passed in, and inherits the content type oftext/plainfromActionDispatch::Responseobject.
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.
# File lib/action_view/helpers/rendering_helper.rb, line 26 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, &block) end end