api-announce.txt @@ -193,23 +193,34 @@ module Erector end # To call one widget from another, inside the parent widget's write method, instantiate the child widget and call - # its +write_via+ method, passing in +self+ (or self.output if you prefer). This assures that the same output string + # its +write_via+ method, passing in +self+. This assures that the same output string # is used, which gives better performance than using +capture+ or +to_s+. - def write_via(widget) - @parent = widget - prepare(widget.output, widget.prettyprint, widget.indentation, widget.helpers) + def write_via(parent) + @parent = parent + prepare(parent.output, parent.prettyprint, parent.indentation, parent.helpers) write end - # TODO: deprecate? - # Convenience method for on-the-fly widgets. This is a way of making - # a sub-widget which still has access to the methods of the parent class. + # Emits a (nested) widget onto the current widget's output stream. Accepts either + # a class or an instance. If the first argument is a class, then the second argument + # is a hash used to populate its instance variables. If the first argument is an + # instance then the hash must be unspecified (or empty). + # + # The sub-widget will have access to the methods of the parent class, via some method_missing + # magic and a "parent" pointer. + # # This is an experimental erector feature which may disappear in future # versions of erector (see #widget in widget_spec in the Erector tests). - def widget(widget_class, assigns={}, &block) - child = widget_class.new(assigns, &block) - child.prepare(output, @prettyprint, @indentation, helpers) - child.write + def widget(target, assigns={}, &block) + child = if target.is_a? Class + target.new(assigns, &block) + else + unless assigns.empty? + raise "Unexpected second parameter. Did you mean to pass in variables when you instantiated the #{target.class.to_s}?" + end + target + end + child.write_via(self) end # (Should we make this hidden?) @@ -467,6 +478,9 @@ protected end attributes ||= {} open_tag tag_name, attributes + if block && value + raise ArgumentError, "You can't pass both a block and a value to #{tag_name} -- please choose one." + end if block instance_eval(&block) else lib/erector/widget.rb @@ -60,7 +60,64 @@ module WidgetSpec end end + describe '#widget' do + context "basic nesting" do + before do + class Parent < Erector::Widget + def write + text 1 + widget Child do + text 2 + third + end + end + + def third + text 3 + end + end + + class Child < Erector::Widget + def write + super + end + end + end + + it "renders nested widgets in the correct order" do + Parent.new.to_s.should == '123' + end + end + + end + describe "#widget" do + class Orphan < Erector::Widget + def write + p name + end + end + + context "when passed a class" do + it "renders it" do + Erector::Widget.new do + div do + widget Orphan, :name => "Annie" + end + end.to_s.should == "<div><p>Annie</p></div>" + end + end + + context "when passed an instance" do + it "renders it" do + Erector::Widget.new do + div do + widget Orphan.new(:name => "Oliver") + end + end.to_s.should == "<div><p>Oliver</p></div>" + end + end + context "when nested" do it "renders the tag around the rest of the block" do parent_widget = Class.new(Erector::Widget) do @@ -584,34 +641,6 @@ module WidgetSpec end end - describe '#widget' do - before do - class Parent < Erector::Widget - def write - text 1 - widget Child do - text 2 - third - end - end - - def third - text 3 - end - end - - class Child < Erector::Widget - def write - super - end - end - end - - it "renders nested widgets in the correct order" do - Parent.new.to_s.should == '123' - end - end - describe '#write_via' do class A < Erector::Widget def write spec/erector/widget_spec.rb api-changes.txt 55268900d4f3fd9ea801550f7f245c16f6a66ff5 Alex Chaffee alex@stinky.com http://github.com/pivotal/erector/commit/0cacf53d2834d107980ef43aca9cf11950ecb606 0cacf53d2834d107980ef43aca9cf11950ecb606 2009-04-20T18:22:25-07:00 2009-04-20T18:22:25-07:00 widget method takes instance or class; documentation and refactoring 0eef48c032ae7c403abab1ea3d809862bfa5ffe6 Alex Chaffee alex@stinky.com