Module: InstanceVariableHash

Defined in:
lib/instance_variable_hash.rb

Overview

This module has two methods to convert between @under_scored_instance_variables and recursive Hashes, see README and the unit tests for examples

Instance Method Summary collapse

Instance Method Details

#instance_variables_get_as_hash(key) ⇒ Object

get all instance variables that begin with ‘key’ as a recursive Hash (separated by _)



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# File 'lib/instance_variable_hash.rb', line 10

def instance_variables_get_as_hash(key)
  response = {} # we need a hash to have an object (id) to attach to
  self.instance_variables.each do |var|
    if var =~ /^@#{Regexp.escape(key.to_s)}(.*)$/ # we take the exact match and the subkeys
      keys, hsh, pre = $1.split('_'), response, []
      keys[0] = key # put the key itself into the result to have it in the loop
      stop = keys.size 
      keys.each do |k|
        pre << k
        if pre.size == stop # last element
          hsh[k] = self.instance_variable_get("@#{pre.join('_')}")
        else
          hsh[k] ||= {} 
          hsh = hsh[k]            
        end
      end
    end
  end
  return response[key]
end

#instance_variables_set_with_hash(hsh) ⇒ Object

set instance variables by a Hash, so that they will end up with underscored names



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# File 'lib/instance_variable_hash.rb', line 40

def instance_variables_set_with_hash(hsh)    
  meth = proc do |pre,h|
    h.each do |k,v|
      keys = (pre.dup << k)
      v.is_a?(Hash) ? meth.call(keys,v) : self.instance_variable_set("@#{keys.join('_')}", v)
    end
  end

  meth.call [], hsh
end

#ivars_from_hash(hsh) ⇒ Object 



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# File 'lib/instance_variable_hash.rb', line 35

def ivars_from_hash(hsh)
  instance_variables_set_with_hash(hsh)
end

#ivars_to_hash(key) ⇒ Object 



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# File 'lib/instance_variable_hash.rb', line 31

def ivars_to_hash(key)
  instance_variables_get_as_hash(key)
end