Thursday, April 03, 2008

Draft of Erector talk

I'm giving a talk on erector in about a week at the Washington, DC Ruby User's Group. Here's a draft of my talk; please provide feedback so I can improve the talk (for example, as comments at the bottom of this page).



Ruby's flexible and minimal syntax makes it well-suited to writing libraries for various tasks


Erector applies that to HTML (or XML) rendering


(start up erector in script/console and go through the following examples)

class Foo < Erector::Widget
def render
html
end
end
Foo.new().to_s


Erector::Widget.new() do
html
end.to_s


Erector::Widget.new() do
p "foo"
end.to_s


Erector::Widget.new() do
text "hello"
end.to_s


Erector::Widget.new() do
p do
text "hello"
b "world"
end
end.to_s


Erector::Widget.new() do
a :href => "a.html" do
text "world"
end
end.to_s


Erector::Widget.new() do
a "world", :href => "a.html" do
end.to_s


Erector::Widget.new() do
text '<>&'
end.to_s

Hooking erector to rails:


class WelcomeController <
ApplicationController

def index
render :text =>
Views::Welcome::Show.new().to_s
end

end

Structuring views with the usual Ruby techniques: especially inheritance and methods


Responsibilities of a view mechanism:


  • quote output


  • balance start/end tags





Comparison with ERB and Markaby, quoting:

ERB: no, must call h

Markaby: for strings, not blocks

Erector: yes*

* except when you call raw


Comparison with ERB and Markaby, tag balancing:

ERB: no

Markaby: yes

Erector: yes*

* except when you call raw


Comparison with ERB and Markaby, subpages:

ERB: partials, helpers

Markaby: partials, helpers

Erector: inheritance, methods


Similar libraries in other languages:




If there is time:

  • Calling helpers from erector

  • Writing helpers in erector