hashmake
Description
Make hash-based object initialization easy!
The hash_make method checks hashed arguments against a set of specifications, then values are assigned to instance variables matching the arg keys.
Features
Type checking via Object#is_a?. The default type is Object, allowing anything. Can allow multiple types. Mark as required/not. Set to true, by default. Default value, for non-required args that aren’t given. For default values that are mutable, make the default value a Proc that can be called to generate the mutable value. Validation of values via a Proc.
Examples
require 'hashmake'
class MyClass
include Hashmake::HashMakeable
ARG_SPECS = {
:x => arg_spec(:reqd => true, :type => Float, :validator => ->(a){ a.between?(0.0,1.0) }),
:y => arg_spec(:reqd => false, :type => Float, :validator => ->(a){ a.between?(0.0,1.0) }, :default => 0.0),
:z => arg_spec_array(:reqd => false, :type => String, :validator => ->(a){ a.size > 0 })
}
attr_reader :x, :y, :z
def initialize hashed_args
hash_make(ARG_SPECS, hashed_args)
end
end
a = MyClass.new :x => 0.5 # a.x => 0.5, a.y => 0.0
a = MyClass.new :x => 0.5, :y => 0.2 # a.x => 0.5, a.y => 0.2
a = MyClass.new # raise ArgumentError because :x is reqd and not given
a = MyClass.new :y => 0.5 # raise ArgumentError because :x is reqd and not given
a = MyClass.new :x => 0.5, :z => ["abc", "efg"] # OK
a = MyClass.new :x => 0.5, :z => ["abc", ""] # raise ArgumentError, because validator requires str.size > 0
class MultitypeDemo
include Hashmake::HashMakeable
ARG_SPECS = {
:str_or_class => arg_spec(:reqd => true, :type => [String, Class])
}
end
MultitypeDemo.new(:str_or_class => "") # OK
MultitypeDemo.new(:str_or_class => String) # OK
MultitypeDemo.new(:str_or_class => 1) # raise ArgumentError
Requirements
Install
$ gem install hashmake
Copyright
Copyright © 2013 James Tunnell
See LICENSE.txt for details.