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