Class: Hashie::Trash

Inherits:
Dash show all
Defined in:
lib/hashie/trash.rb

Overview

A Trash is a 'translated' Dash where the keys can be remapped from a source hash.

Trashes are useful when you need to read data from another application, such as a Java api, where the keys are named differently from how we would in Ruby.

Class Method Summary collapse

Instance Method Summary collapse

Methods inherited from Dash

#[], inherited, #initialize, property?, #replace, required?

Methods included from PrettyInspect

#hashie_inspect, included

Methods inherited from Hash

#to_hash, #to_json

Methods included from HashExtensions

#hashie_stringify_keys, #hashie_stringify_keys!, included, #to_mash

Constructor Details

This class inherits a constructor from Hashie::Dash

Class Method Details

.property(property_name, options = {}) ⇒ Object

Defines a property on the Trash. Options are as follows:

  • :default - Specify a default value for this property, to be returned before a value is set on the property in a new Dash.
  • :from - Specify the original key name that will be write only.
  • :with - Specify a lambda to be used to convert value.
  • :transform_with - Specify a lambda to be used to convert value without using the :from option. It transform the property itself.

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# File 'lib/hashie/trash.rb', line 20

def self.property(property_name, options = {})
  super

  if options[:from]
    if property_name.to_sym == options[:from].to_sym
      raise ArgumentError, "Property name (#{property_name}) and :from option must not be the same"
    end
    translations << options[:from].to_sym
    if options[:with].respond_to? :call
      class_eval do
        define_method "#{options[:from]}=" do |val|
          self[property_name.to_sym] = options[:with].call(val)
        end
      end
    else
      class_eval <<-RUBY
        def #{options[:from]}=(val)
          self[:#{property_name}] = val
        end
      RUBY
    end
  elsif options[:transform_with].respond_to? :call
    transforms[property_name.to_sym] = options[:transform_with]
  end
end

Instance Method Details

#[]=(property, value) ⇒ Object

Set a value on the Dash in a Hash-like way. Only works on pre-existing properties.


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# File 'lib/hashie/trash.rb', line 48

def []=(property, value)
  if self.class.translations.include? property.to_sym
    send("#{property}=", value)
  elsif self.class.transforms.key? property.to_sym
    super property, self.class.transforms[property.to_sym].call(value)
  elsif property_exists? property
    super
  end
end