Module | Nanoc::Helpers::Rendering |
In: |
lib/nanoc/helpers/rendering.rb
|
Provides functionality for rendering layouts as partials.
Renders the given layout. The given layout will be run through the first matching layout rule.
When this method is invoked without a block, the return value will be the rendered layout (a string) and `_erbout` will not be modified.
When this method is invoked with a block, an empty string will be returned and the rendered content will be appended to `_erbout`. In this case, the content of the block will be captured (using the {Nanoc::Helpers::Capturing} helper) and this content will be made available with `yield`. In other words, a `yield` inside the partial will output the content of the block passed to the method.
(For the curious: the reason why {render} with a block has this behaviour of returning an empty string and modifying `_erbout` is because ERB does not support combining the `<%= … %>` form with a method call that takes a block.)
The assigns (`@item`, `@config`, …) will be available in the partial. It is also possible to pass custom assigns to the method; these assigns will be made available as instance variables inside the partial.
@param [String] identifier The identifier of the layout that should be
rendered
@param [Hash] other_assigns A hash containing extra assigns that will be
made available as instance variables in the partial
@example Rendering a head and a foot partial around some text
<%= render 'head' %> - MIDDLE - <%= render 'foot' %> # => "HEAD - MIDDLE - FOOT"
@example Rendering a head partial with a custom title
# The 'head' layout <h1><%= @title %></h1> # The item/layout where the partial is rendered <%= render 'head', :title => 'Foo' %> # => "<h1>Foo</h1>"
@example Yielding inside a partial
# The 'box' partial <div class="box"> <%= yield %> </div> # The item/layout where the partial is rendered <% render 'box' do %> I'm boxy! Luvz! <% end %> # Result <div class="box"> I'm boxy! Luvz! </div>
@raise [Nanoc::Errors::UnknownLayout] if the given layout does not
exist
@raise [Nanoc::Errors::CannotDetermineFilter] if there is no layout
rule for the given layout
@raise [Nanoc::Errors::UnknownFilter] if the layout rule for the given
layout specifies an unknown filter
@return [String, nil] The rendered partial, or nil if this method was
invoked with a block