Caesar - v0.3

A simple class for rapid DSL prototyping in Ruby.

NOTE: Currently runs only with Ruby 1.9+!

Installation

One of:

  • copy lib/caesar.rb into your lib directory.

Or for GitHub fans:

  • git clone git://github.com/delano/caesar.git

  • gem sources -a gems.github.com (you only have to do this once, ever…), then:

    • gem install delano-caesar

Usage

# ------------------------------------------------------------------
#   EXAMPLE 1 -- Flavour
# 

class Flavour < Caesar  # Subclass Caesar. 
end

extend Flavour::DSL     # Bring the DSL into the current namespace. 
                        # This module is created dynamically based
                        # on the name of the subclass.

flavour do              # Start drinking! I mean, start writing your
  spicy true            # domain specific language! 
  clamy true            # Use any attribute name you want.
  salty true
  vodka :very_true      # And any value you want. 
end

p @flavour              # => #<Flavour:0x3f56b0 ...>
p @flavour.spicy        # => true

# ------------------------------------------------------------------
# EXAMPLE 2 -- Staff
#

# Tell Caesar which attributes have children using Caesar#bloody and 
# which have blocks that you want to execute later using Caesar#virgin.
class Staff < Caesar 
  bloody :location
  bloody :person
  virgin :calculate
end

extend Staff::DSL

# The top level method is the lower case name of the class. For deeper
# names like Class::SecondLevel it will use the final name 
# (i.e. secondlevel). You can supply an optional modifier name which 
# will be included in the instance variable (@staff_fte).
staff :fte do
  desc 'Our hard-working, "full-time" staff'
  location :splashdown do
    town :tsawwassen
    person :steve, :sheila do
      role :manager
    end
    person :steve do
      role :cook
      anger :high
      hours 25
      catchphrase "Rah! [strokes goatee]"
    end
    person :sheila do
      catchphrase "This gravy tastes like food I ate in a Mexican prison."
      hours rand(20)
      rate "9.35/h"
      calculate :salary do |gumption|
        ("%.2f" % [gumption * self.splashdown.sheila.rate.to_f]).to_f
      end
    end
    person :delano do
      role :cook
      rate "8.35/h"
      hours 57
      satisfaction :low
      calculate :salary do 
        self.splashdown.delano.rate.to_f * self.splashdown.delano.hours
      end
    end
  end
end

p @staff_fte                    # => #<KitchenStaff: ...>
p @staff_fte.desc               # => Our hard-working, "full-time" staff

# Deeper attributes are also available via instance methods
p @staff_fte.splashdown.delano  # => {:role=>:cook, :rate=>"$8.35/h", :satisfaction=>:low}
p @staff_fte.splashdown.sheila  # => {:role=>:manager, :catchphrase=>"This gravy tastes like food I ate in a Mexican prison."}
p @staff_fte.splashdown.steve   # => {:role=>[:manager, :cook], :anger=>:high, :catchphrase=>"Rah! [strokes goatee]"}
p @staff_fte.splashdown.delano.satisfaction   # => :low

# You can also access them using hash syntax
p @staff_fte.splashdown[:steve][:role]  # => [:manager, :cook]

# The "bloody" attributes keep track of all values that are used. These are available as arrays
# via "NAME_values" methods. The goes for the virgin ones. 
p @staff_fte.location_values    # => [:splashdown]
p @staff_fte.person_values.uniq # => [:steve, :sheila, :delano, :angela]
p @staff_fte.calculate_values   # => [:salary, :salary]

# The "virgin" methods store their blocks as Procs and are not executed automatically. 
# You can call them manually and send arguments like you normally would. 
p @staff_fte.splashdown.delano.salary.call             # => 475.95
p @staff_fte.splashdown.sheila.salary.call(rand(100))  # => 549.77

More Info

Credits

Thanks

  • Clams, Tomatoes, Vodka, and the rest of the crew.

License

See: LICENSE.txt