Wee 2.0.0 Released

Around 4 years have passed since the last release of Wee.

What is Wee?

Wee is a web-framework for building highly-dynamic component-based web-applications inspired by Seaside.

What’s new?

• 100% Rack based
• Support for continuations
• JQuery AJAX support
• Ruby 1.9 ready

Distinctive Features

Wee is not just another web framework. It is completely different.

Continuations

You can use continuations to model the page flow of the your application, in the same way as you’d call a method in a GUI application. Continuations are optional; nothing in Wee depends on them. Example:

# you can write code like this:

if callcc YesNoMessageBox.new('Really?')
  # do something
else
  # something else
end

Without continuations one has to use (ugly) Continuation Passing Style (CPS):

call YesNoMessageBox.new('Really?') do |res|
  if res
    # do something
  else
    # something else
  end
end

Backtracking

Backtracking means that the user can naturally use the browsers back button despite Wee’s statefulness. This is not taken for granted for stateful web frameworks. Behind the scenes, Wee keeps multiple states of the application around with only little help by the programmer.

Components

Contrary to the widely used model/view/controller (MVC) paradigm, Wee tighly couples the controller and the view within a component. Components itself are highly decoupled from the rest of the application and can be reused to construct more complex applications. The powerful programmatic HTML rendering approach further reduces wasting the programmers mind by avoiding switching files (controller/view) or languages (Ruby/HTML). Therefore in Wee everything is written in Ruby. The programmatic HTML renderer is not just a simple HTML builder, it provides very powerful methods for easily generating HTML constructs and registering callbacks. Example:

#
# Generating a <select> tag
#

# select an object from these items
items = [1, 2, 3, 4]

# the labels shown to the user
labels = items.map {|i| i.to_s}

# render it
r.select_list(items).labels(labels).callback {|choosen| p choosen}

# render a multi-select list, with objects 2 and 4 selected
r.select_list(items).multi.labels(labels).selected([2,4])

Call/Answer mechanism

From callback handlers you can call other components which in turn replace the current components view. The called component can later return (or answer) back to the calling componenent. Example:

class YesNoMessageBox < Wee::Component
  def initialize(msg)
    super()
    @msg = msg
  end

  def render(r)
    r.bold(@msg)
    r.form do
      r.submit_button.value('YES').callback { answer true }
      r.space
      r.submit_button.value('No').callback { answer false }
    end
  end
end

# Use call (or callcc) as in the Continuation section above
# to call a component:
call YesNoMessageBox.new('Really?')

The classical Hello World Example

require 'rubygems' if RUBY_VERSION < "1.9"
require 'wee'

class HelloWorld < Wee::Component
 def initialize
   super
   add_decoration Wee::PageDecoration.new(title="Hello World")
 end

 def render(r)
   r.h1 "Hello World from Wee!"
   r.div.onclick_callback { p "clicked" }.with("click here")
 end
end

Wee.run(HelloWorld) if __FILE__ == $0
# Now point your browser to http://localhost:2000/

Installation

gem install wee