Class: Dao::Extractor

Inherits:
BlankSlate show all
Defined in:
lib/dao/extractor.rb

Instance Attribute Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(target, *args, &block) ⇒ Extractor

Returns a new instance of Extractor.



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# File 'lib/dao/extractor.rb', line 8

def initialize(target, *args, &block)
  @target = target
  @strategies = Map.new
  @extracted = Map.new
  extracts(*args)
end

Dynamic Method Handling

This class handles dynamic methods through the method_missing method

#method_missing(method, *args, &block) ⇒ Object 



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# File 'lib/dao/extractor.rb', line 42

def method_missing(method, *args, &block)
  super unless @strategies.has_key?(method)
  extract(method, &@strategies[method])
end

Instance Attribute Details

#extracted ⇒ Object (readonly)

Returns the value of attribute extracted.



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# File 'lib/dao/extractor.rb', line 5

def extracted
  @extracted
end

#strategies ⇒ Object (readonly)

Returns the value of attribute strategies.



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# File 'lib/dao/extractor.rb', line 6

def strategies
  @strategies
end

#target ⇒ Object (readonly)

Returns the value of attribute target.



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# File 'lib/dao/extractor.rb', line 4

def target
  @target
end

Instance Method Details

#extract(attribute, &block) ⇒ Object 



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# File 'lib/dao/extractor.rb', line 47

def extract(attribute, &block)
  return @extracted[attribute] if @extracted.has_key?(attribute)

  if @target.respond_to?(attribute)
    value = @target.send(attribute)
    @extracted[attribute] = value
    return @extracted[attribute]
  end

  ivar = "@#{ attribute }"
  if @target.instance_variable_defined?(ivar)
    value = @target.instance_variable_get(ivar)
    @extracted[attribute] = value
    return @extracted[attribute]
  end

  if block
    @extracted[attribute] = block.call
    return @extracted[attribute]
  end
end

#extracts(*args, &block) ⇒ Object 



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# File 'lib/dao/extractor.rb', line 19

def extracts(*args, &block)
  hashes = []

  args.each do |arg|
    if arg.is_a?(Hash)
      hashes.push(arg)
    else
      if block
        hashes.push(arg => block)
      end
    end
  end

  hashes.each do |hash|
    hash.each do |key, val|
      next unless val.respond_to?(:call)
      @strategies[key] = val
    end
  end

  self
end

#inspect ⇒ Object 



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# File 'lib/dao/extractor.rb', line 15

def inspect
  @extracted.inspect
end