Module: VirtualBox::AbstractModel::Attributable::ClassMethods

Defined in:
lib/virtualbox/abstract_model/attributable.rb

Overview

Defines the class methods for the VirtualBox::AbstractModel::Attributable module. For detailed overview documentation, see VirtualBox::AbstractModel::Attributable.

Instance Method Summary collapse

Instance Method Details

#attribute(name, options = {}) ⇒ Object

Defines an attribute on the model.

Parameters:

  • name (Symbol) —

    The name of the attribute, which will also be used to set the accessor methods.

  • options (Hash) (defaults to: {}) —

    a customizable set of options

Options Hash (options):

  • :readonly (Boolean) — default: false —

    If true, attribute will be readonly. More specifically, the ‘attribute=` method won’t be defined for it.

  • :default (Object) — default: nil —

    Specifies a default value for the attribute.

  • :populate_key (Symbol) — default: attribute name —

    Specifies a custom populate key to use for VirtualBox::AbstractModel::Attributable#populate_attributes



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# File 'lib/virtualbox/abstract_model/attributable.rb', line 154

def attribute(name, options = {})
  name = name.to_sym
  attributes[name] = defined?(@__attribute_scope) ? @__attribute_scope : {}
  attributes[name].merge!(options)

  # Create the method for reading this attribute
  define_method("#{name}?") { read_attribute(name) } if options[:boolean]
  define_method(name) { read_attribute(name) }

  # Create the writer method for it unless the attribute is readonly,
  # then remove the method if it exists
  if !options[:readonly]
    define_method("#{name}=") do |value|
      write_attribute(name, value)
    end
  elsif method_defined?("#{name}=")
    undef_method("#{name}=")
  end
end

#attribute_scope(options, &block) ⇒ Object

Defines the specified scope for all attributes within the block. The scope is reset to the previous value once the block ends. Multiple scopes can be nested and they’ll inherit from each other.



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# File 'lib/virtualbox/abstract_model/attributable.rb', line 177

def attribute_scope(options, &block)
  @__attribute_scope ||= {}
  old_value = @__attribute_scope
  @__attribute_scope = old_value.merge(options)

  instance_eval(&block)

  @__attribute_scope = old_value
end

#attributes ⇒ Object

Returns the hash of attributes and their associated options.



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# File 'lib/virtualbox/abstract_model/attributable.rb', line 188

def attributes
  @attributes ||= {}
end

#inherited(subclass) ⇒ Object

Used to propagate attributes to subclasses. This method makes sure that subclasses of a class with VirtualBox::AbstractModel::Attributable included will inherit the attributes as well, which would be the expected behaviour.



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# File 'lib/virtualbox/abstract_model/attributable.rb', line 195

def inherited(subclass)
  super rescue NoMethodError

  attributes.each do |name, option|
    subclass.attribute(name, option)
  end
end