Method: DataModel::Struct.prop

Defined in:
lib/data_model/struct.rb

.prop(name, schema, opts = {}) ⇒ void

This method returns an undefined value.

Define a property on the struct.

Parameters:

  • name (Symbol) —

    the name of the property

  • schema (Array) —

    the schema to define

  • opts (Hash) (defaults to: {}) —

    a customizable set of options

Options Hash (opts):

  • :default (Boolean) —

    the default value for the property



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# File 'lib/data_model/struct.rb', line 19

def self.prop(name, schema, opts = {})
	has_default = opts.key?(:default)
	default = opts[:default]

	# ensure values are initialized
	@types ||= {}
	@required_types ||= []

	# if a prop does not have a default, it is required
	if !has_default
		@required_types << name
	end

	# store the data model for the prop
	schema = Array(schema)
	@types[name] = DataModel.define(schema)

	# field getter
	define_method(name) do
		@values ||= {}
		types = self.class.types

		if !types.key?(name)
			raise "No prop configured for #{name}"
		end

		if !@values.key?(name) && has_default
			return default
		end

		return @values[name]
	end

	# field setter
	define_method("#{name}=") do |val|
		@values ||= {}
		types = self.class.types

		if !types.key?(name)
			raise "No prop configured for #{name}"
		end

		model = types.fetch(name)

		if @coerce
			val, err = model.coerce(val)
		else
			err = model.validate(val)
		end

		if @strict && err.any?
			errors.merge_child(prop, err)
			raise "Invalid value for #{name}: #{err.to_messages.inspect}"
		end

		@values[name] = val
	end
end