API.md

Functions

extend(BaseRecord, descriptor, [label])

Extends a record type and allows the addition of new fields

Maybe(Type, [defaultValue])

Defines an optional type, similar to typed-immutable's Maybe, but provides extended options.

Benefits over typed-immutable's Maybe:

• Allows both undefined and null as values
• Allows defining a default value for when the value is undefined
• Extracts the default value from the Type parameter if one is defined

Enum(enumValues, [defaultValue])

Restricts the values which can be set on a property.

Discriminator(property, typeMap, [defaultType])

Chooses the type to use based on the value of a property.

extend(BaseRecord, descriptor, [label])

Extends a record type and allows the addition of new fields

Kind: global function

Param	Type	Description
BaseRecord	Record	Record to extend
descriptor	object	Descriptor object of new fields to add
[label]	string	Label for the new Record type

Example

const BaseValue = Record({
  type: String,
});

const StringValue = extend(BaseValue, {
  value: String,
});

const NumberValue = extend(BaseValue, {
  value: Number,
});

Maybe(Type, [defaultValue])

Defines an optional type, similar to typed-immutable's Maybe, but provides extended options.

Benefits over typed-immutable's Maybe:

• Allows both undefined and null as values
• Allows defining a default value for when the value is undefined
• Extracts the default value from the Type parameter if one is defined

Kind: global function

Param	Type	Description
Type	*	Type of the value
[defaultValue]	*	Default value (must be undefined, null, or of the specified Type)

Example

const MyRecord = Record({
 //Required string
 id: String,
 //Required string with a default value
 name: 'Some Name',
 //Optional string - defaults to undefined
 value: Maybe(String),
 //Optional string with a default value
 type: Maybe(String, 'point'),
 //Optional string with a default value (extracted from the type)
 text: Maybe('Some Text'),
 //Optional string with a default value of null
 title: Maybe(String, null),
});

Enum(enumValues, [defaultValue])

Restricts the values which can be set on a property.

Kind: global function

Param	Type	Description
enumValues	Array.<*>	Array of possible values
[defaultValue]	*	Default value (must be in the set of enumValues)

Example

const MyRecord = Record({
  //Restricts values to "text" and "image"
  type: Enum(['text', 'image']),
  //Restricts values to "left", "center" and "image" with a default value of "left" if the value is undefined
  alignment: Enum(['left', 'center', 'right'], 'left')
});

Discriminator(property, typeMap, [defaultType])

Chooses the type to use based on the value of a property.

Kind: global function

Param	Type	Description
property	string	Property to use for determining the type
typeMap	object.<Record>	Map of property values to types
[defaultType]	Record	Default type when no property value is found in the typeMap

Example

const StringValue = Record({
  type: String,
  value: String,
});

const NumberValue = Record({
  type: String,
  value: Number,
});

const AnyValue = Record({
  type: String,
  value: Any,
});

const MyRecord = Record({
  //Chooses the Record type to use based on the "type" property value
  value: Discriminator('type', {
    'string': StringValue,
    'number': NumberValue,
  }),
  //Defaults to AnyValue if no matching type is found
  other: Discriminator('type', {
    'string': StringValue,
    'number': NumberValue,
  }, AnyValue),
});