@kingjs/object-ex

Usage

var objectEx = require('@kingjs/object-ex');

Property descriptors are divided into classes named:

• field
• function
• accessor
• property

Each class name is prefixed with various combinations to form an export:

• set or define: Configurable or not configurable respectively.
• hidden: Not enumerable, otherwise enumerable
• const: Not writable, otherwise writable
• lazy: Inject stub that will cache result on this at runtime.
• static: Modifies lazy. Use if target and this are the same at runtime.

Each function ultimately calls @kingjs/property-descriptor.create.

Each class of exports supports different overrides. For example the following are equivalent:

defineFunction(target, 'foo', { value: function() { ... } })
defineFunction(target, { value: function foo() { ... } })
defineFunction(target, function foo() { ... })

Any properties specified in an override that takes a descriptor will override those properties implied by the prefix. For example, the following will produce an enumerable accessor:

defineHiddenAccessor(target, 'bar', { enumerable: true, get: () => ... })

Strings that appear where functions are expected will be used to construct an appropriate Function. For example, the following are equivalent:

// function lambda
defineFunction(target, 'foo', 'this.bar')
defineFunction(target, 'foo', function() { return this.bar; })

// get/set lambdas
defineFunction(target, 'foo', 'this.bar', 'this.bar = value')
defineAccessor(target, 'foo', 
  function() { return this.bar; })
  function(value) { this.bar = value; }
)

// function NOT expected so string treated as a value
defineField(target, 'foo', 'this.bar')
defineProperty(target, 'foo', { value: 'this.bar' })

Property API

These overrides are supported for all APIs, not just defineProperty:

defineProperty(target, namedFunction)
defineProperty(target, name, function)
defineProperty(target, name, { value: function, ... })

|API|lazy|static| |---|---|---| |defineProperty| |defineLazyProperty|x| |defineLazyStaticProperty|x|x|

Function API

The Function API family is just like the Property API family except all descriptors are tagged with function. So the following are equivalent:

defineFunction(target, namedFunction)
defineFunction(target, name, function)
defineFunction(target, name, { value: function, ... })
defineProperty(target, name, { value: function, function: true, ... })

|API|function|lazy|static| |---|---|---|---| |defineFunction|x| |defineLazyFunction|x|x| |defineLazyStaticFunction|x|x|x|

Field API

The Field family does not support passing a descriptor. Instead, the value is always wrapped in a descriptor as value. So the following are equivalent:

defineField(target, name, value)
defineProperty(target, name, { value })

|API|configurable|enumerable|writable| |---|---|---|---| |setField|x|x|x| |setHiddenField|x||x| |setConstField|x|x|| |setHiddenConstField|x|| |defineField||x|x| |defineHiddenField|||x| |defineConstField||x|| |defineHiddenConstField|||

Accessor API

These overrides are supported for all prefixes, not just defineAccessor:

defineAccessor(target, namedGetter[, namedSetter])
defineAccessor(target, name, getter[, setter])
defineAccessor(target, { namedGetter[, namedSetter], ... })
defineAccessor(target, name, { getter[, setter], ... })

|API|configurable|enumerable|lazy|static| |---|---|---|---|---| |setAccessor|x|x| |setHiddenAccessor|x| |setLazyAccessor|x|x|x| |setHiddenLazyAccessor|x||x| |setLazyStaticAccessor|x|x|x|x| |setHiddenLazyStaticAccessor|x||x|x| |defineAccessor||x| |defineHiddenAccessor| |defineLazyAccessor||x|x| |defineHiddenLazyAccessor|||x| |defineLazyStaticAccessor||x|x|x| |defineHiddenLazyStaticAccessor|||x|x|

Remarks

Install

With npm installed, run

$ npm install @kingjs/object-ex

License

MIT