Class: VacuumCleaner::Normalizations::MethodNormalizer

Inherits:
VacuumCleaner::Normalizer show all
Defined in:
lib/vacuum_cleaner/normalizations/method.rb

Overview

Generic method based normalizer which just calls supplied method on value (unless nil).

normalizes :name, :method => :titelize

Custom instances accept a :method option.

MethodNormalizer.new(:method => :titelize)

Subclasses of the MethodNormalizer can take advantage of it’s normalize_if_respond_to method, to easily create custom normalizers based on methods availble on the result value.

Instance Attribute Summary

Attributes inherited from VacuumCleaner::Normalizer

#options

Class Method Summary collapse

Instance Method Summary collapse

Methods inherited from VacuumCleaner::Normalizer

#normalize

Constructor Details

#initialize(args = {}) ⇒ MethodNormalizer

Accept either a hash or symbol name.



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# File 'lib/vacuum_cleaner/normalizations/method.rb', line 39

def initialize(args = {})
  args = { :method => args } unless args.is_a?(Hash)
  super(args)
end

Class Method Details

.build(sym) ⇒ Object

Helper method to “bake” a method normalizer from a method, enabling us to do stuff like.

TitelizeNormalizer = MethodNormalizer.build(:titleize)



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# File 'lib/vacuum_cleaner/normalizations/method.rb', line 23

def build(sym)
  module_eval "Class.new(MethodNormalizer) do; def initialize(*args); super({ :method => #{sym.inspect}}) end; end", __FILE__, __LINE__
end

.multibyte_wrapper ⇒ Object 



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# File 'lib/vacuum_cleaner/normalizations/method.rb', line 35

def multibyte_wrapper; @multibyte_wrapper end

.multibyte_wrapper=(clazz) ⇒ Object

Due to the lack of multibyte support in ruby core, a proxy class like ActiveSupport::Multibyte::Chars can be registered here and the proxy is then used to wrap string values within, so that methods like upcase or downcase work with characters outside the ASCII range as well.

The wrapper is only used if the value supplied is a string, i.e. responds to to_str.



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# File 'lib/vacuum_cleaner/normalizations/method.rb', line 34

def multibyte_wrapper=(clazz); @multibyte_wrapper = clazz end

Instance Method Details

#normalize_value(value) ⇒ Object

Normalize value by trying to call the method at hand, if value does not respond to the defined method, returns nil.



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# File 'lib/vacuum_cleaner/normalizations/method.rb', line 46

def normalize_value(value)
  sym = options[:method]
  value = MethodNormalizer.multibyte_wrapper.new(value) if MethodNormalizer.multibyte_wrapper and value.respond_to?(:to_str)
  value.respond_to?(sym) ? value.send(sym) : nil
end