module Hashie::Extensions::Coercion::ClassMethods

Attributes

key_coercions[W]

Public Instance Methods

build_coercion(type) click to toggle source
# File lib/hashie/extensions/coercion.rb, line 156
def build_coercion(type)
  if type.is_a? Enumerable
    if type.class <= ::Hash
      type, key_type, value_type = type.class, *type.first
      build_hash_coercion(type, key_type, value_type)
    else # Enumerable but not Hash: Array, Set
      value_type = type.first
      type = type.class
      build_container_coercion(type, value_type)
    end
  elsif CORE_TYPES.key? type
    build_core_type_coercion(type)
  elsif type.respond_to? :coerce
    lambda do |value|
      return value if value.is_a? type
      type.coerce(value)
    end
  elsif type.respond_to? :new
    lambda do |value|
      return value if value.is_a? type
      type.new(value)
    end
  else
    fail TypeError, "#{type} is not a coercable type"
  end
end
build_container_coercion(type, value_type) click to toggle source
# File lib/hashie/extensions/coercion.rb, line 191
def build_container_coercion(type, value_type)
  value_coerce = fetch_coercion(value_type)
  lambda do |value|
    type.new(value.map { |v| value_coerce.call(v) })
  end
end
build_core_type_coercion(type) click to toggle source
# File lib/hashie/extensions/coercion.rb, line 198
def build_core_type_coercion(type)
  name = CORE_TYPES[type]
  lambda do |value|
    return value if value.is_a? type
    return value.send(name)
  end
end
build_hash_coercion(type, key_type, value_type) click to toggle source
# File lib/hashie/extensions/coercion.rb, line 183
def build_hash_coercion(type, key_type, value_type)
  key_coerce = fetch_coercion(key_type)
  value_coerce = fetch_coercion(value_type)
  lambda do |value|
    type[value.map { |k, v| [key_coerce.call(k), value_coerce.call(v)] }]
  end
end
coerce_key(*attrs) click to toggle source

Set up a coercion rule such that any time the specified key is set it will be coerced into the specified class. Coercion will occur by first attempting to call Class.coerce and then by calling Class.new with the value as an argument in either case.

@param [Object] key the key or array of keys you would like to be coerced. @param [Class] into the class into which you want the key(s) coerced.

@example Coerce a “user” subhash into a User object

class Tweet < Hash
  include Hashie::Extensions::Coercion
  coerce_key :user, User
end
# File lib/hashie/extensions/coercion.rb, line 72
def coerce_key(*attrs)
  into = attrs.pop
  attrs.each { |key| key_coercions[key] = into }
end
Also aliased as: coerce_keys
coerce_keys(*attrs)
Alias for: coerce_key
coerce_value(from, into, options = {}) click to toggle source

Set up a coercion rule such that any time a value of the specified type is set it will be coerced into the specified class.

@param [Class] from the type you would like coerced. @param [Class] into the class into which you would like the value coerced. @option options [Boolean] :strict (true) whether use exact source class only or include ancestors

@example Coerce all hashes into this special type of hash

class SpecialHash < Hash
  include Hashie::Extensions::Coercion
  coerce_value Hash, SpecialHash

  def initialize(hash = {})
    super
    hash.each_pair do |k,v|
      self[k] = v
    end
  end
end
# File lib/hashie/extensions/coercion.rb, line 110
def coerce_value(from, into, options = {})
  options = { strict: true }.merge(options)

  if ABSTRACT_CORE_TYPES.key? from
    ABSTRACT_CORE_TYPES[from].each do |type|
      coerce_value type, into, options
    end
  end

  if options[:strict]
    strict_value_coercions[from] = into
  else
    while from.superclass && from.superclass != Object
      lenient_value_coercions[from] = into
      from = from.superclass
    end
  end
end
coercion_cache() click to toggle source
# File lib/hashie/extensions/coercion.rb, line 150
def coercion_cache
  @coercion_cache ||= ::Hash.new do |hash, type|
    hash[type] = build_coercion(type)
  end
end
fetch_coercion(type) click to toggle source
# File lib/hashie/extensions/coercion.rb, line 145
def fetch_coercion(type)
  return type if type.is_a? Proc
  coercion_cache[type]
end
inherited(klass) click to toggle source
Calls superclass method
# File lib/hashie/extensions/coercion.rb, line 206
def inherited(klass)
  super

  klass.key_coercions = key_coercions.dup
end
key_coercion(key) click to toggle source

Returns the specific key coercion for the specified key, if one exists.

# File lib/hashie/extensions/coercion.rb, line 86
def key_coercion(key)
  key_coercions[key.to_sym]
end
key_coercions() click to toggle source

Returns a hash of any existing key coercions.

# File lib/hashie/extensions/coercion.rb, line 80
def key_coercions
  @key_coercions ||= {}
end
lenient_value_coercions() click to toggle source

Return all value coercions that have the :strict rule as false.

# File lib/hashie/extensions/coercion.rb, line 135
def lenient_value_coercions
  @lenient_value_coercions ||= {}
end
strict_value_coercions() click to toggle source

Return all value coercions that have the :strict rule as true.

# File lib/hashie/extensions/coercion.rb, line 130
def strict_value_coercions
  @strict_value_coercions ||= {}
end
value_coercion(value) click to toggle source

Fetch the value coercion, if any, for the specified object.

# File lib/hashie/extensions/coercion.rb, line 140
def value_coercion(value)
  from = value.class
  strict_value_coercions[from] || lenient_value_coercions[from]
end