Class: HashCollector

Inherits:
Object show all
Defined in:
lib/qtext/hash_collector.rb

Overview

A DSL class that allows options to be collected for a field definition using a block and/or a hash.

hash = { :colour => :red, :hue => 15 }
collector = HashCollector.new( hash ) do |hc|
  hc.saturation = 17
  hc.opacity = 0.43
  hc.grooviness = 100
end

or like this (without the block parameter)

collector = HashCollector.new( hash ) do
  saturation 17
  opacity 0.43
  grooviness = 100
end

either way, a call to collector.to_hash will result in

{ :hue=>15, :saturation=>17, :opacity=>0.43, :grooviness=>100, :colour=>:red }

and the following accessors will be added

collector.hue
collector.hue( some_value )
collector.hue = some_value

for hue, saturation, opacity, grooviness and colour.

Direct Known Subclasses

IndexCollector

Instance Method Summary collapse

Constructor Details

#initialize(hash = {}, &block) ⇒ HashCollector

Collect values from the hash and the block, using the collect method.



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# File 'lib/qtext/hash_collector.rb', line 30

def initialize( hash = {}, &block )
  @hash = hash || {}
  gather( &block )
end

Dynamic Method Handling

This class handles dynamic methods through the method_missing method

#method_missing(sym, *args) ⇒ Object (protected)

Originally from Jim Freeze’s article. Add the accessor methods if they don’t already exist, and if dsl_dynamic is in effect, which is the default. If dsl_static is in effect, the normal method_missing behaviour will be invoked.



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# File 'lib/qtext/hash_collector.rb', line 111

def method_missing(sym, *args)
  if self.class.dynamic?
    self.class.dsl_accessor sym
    send( sym, *args )
  else
    super
  end
end

Instance Method Details

#collect(args = {}, &block) ⇒ Object

evaluate the block and collect options from args. Even if it’s nil.



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# File 'lib/qtext/hash_collector.rb', line 36

def collect( args = {}, &block )
  @hash.merge!( args || {} )
  unless block.nil?
    if block.arity == -1
      instance_eval &block
    else
      yield self
    end
  end
end

#to_hash ⇒ Object

return a hash of the collected elements



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# File 'lib/qtext/hash_collector.rb', line 48

def to_hash
  @hash
end