Introduction

enum-props wraps the excellent enum implementation adrai/enum. It exposes an Enum factory that allows additional metadata to be added to each enum member.

Installation

npm install -S enum-props

Usage

var Enum = require('enum-props');

// define a simple enum (automatically flaggable -> A: 0x01, B: 0x02, C: 0x04)
//Uses bitwise 'OR' operation in between the values and creates enumerated constants. For example, if 'Read':1, 'Write':2, then ReadWrite= Read | Write = 1 | 2 = 3;
var myEnum = new Enum(['A', 'B', 'C']);

//define a flagged enum object to create a multicolor option; just pass an array
var myEnum = new Enum(['Black', 'Red', 'Green', 'Blue']);
myEnum; //=> Enum {_options: Object, enums: Array[4], Black: EnumItem, Red: EnumItem, Green: EnumItem….....}
myEnum.isFlaggable; //=> true

for(var i=1; i<8; i++){ console.log(myEnum.get(i).value + '=> '+ myEnum.get(i).key)}
    1=> Black
    2=> Red
    3=> Black | Red
    4=> Green
    5=> Black | Green
    6=> Red | Green
    7=> Black | Red | Green

// define an enum with own values
var myEnum = new Enum({'A': 1, 'B': 2, 'C': 4});

//define enum type without flag
var myEnum = new Enum({'None': 0, 'Black':1, 'Red': 2, 'Red2': 3, 'Green': 4, 'Blue': 5});
myEnum; //=>  Enum {_options: Object, enums: Array[6], None: EnumItem, Black: EnumItem, Red: EnumItem...}
myEnum.isFlaggable; //=> false

for(var i=0; i<=5; i++){ console.log(myEnum.get(i).value + '=> '+ myEnum.get(i).key)}
    0=> None
    1=> Black
    2=> Red
    3=> Red2
    4=> Green
    5=> Blue

// define an enum with own custom properties
var myEnum = new Enum({
    'A': { value: 1, descrip: 'first' }, 
    'B': { value: 2, descrip: 'second' }, 
    'C': { value: 4, descrip: 'third' }
});

myEnum.A.value // => 1
myEnum.A.description // => 'first'

// enums and their members are frozen
myEnum.A.description = 'this is ignored'
myEnum.A.description // => 'first'

// iterating over an enum
myEnum.enums.forEach(function(enumItem) {
  console.log(enumItem.key);
});
// => None
// => Black
// => Red
// => Red2
// => Green
// => Blue

// get your item
myEnum.A

// or
myEnum.get('A')

// or
myEnum.get(1)

// or
myEnum.get('A | B')

// or
myEnum.get(3)


// get your value
myEnum.A.value

// get your key
myEnum.A.key


// get all items
myEnum.enums // returns all enums in an array


// compare
myEnum.A.is(myEnum.A)

// or
myEnum.A.is('A')

// or
myEnum.A.is(1)

// or
myEnum.A == 'A'

// or
myEnum.A == myEnum.A

// or
myEnum.A === myEnum.A


// check flag
var myItem = myEnum.get(3); // or [myEnum.get('A | B')]
myItem.has(myEnum.A)

// or
myItem.has('A')

// or
myItem.has(1)


// other functions
myItem.toString() // returns 'A | C'
myItem.toJSON() // returns '"A | C"'
myItem.valueOf() // returns 3

JSON.stringify(myItem) // returns '"A | C"'


//Type Safety:
//Newly created enumerable objects are Type-Safe in a way that it's non-configurable and no longer extensible.
//Each EnumItem has a beack-reference to a constructor and they are implicitly final.
Object.getOwnPropertyDescriptor(myEnum, 'Red'); //=> Object {value: EnumItem, writable: false, enumerable: true, configurable: false}
Object.isExtensible(myEnum); //=> false
myEnum instanceof Enum; //=> true

//Instances of Enum created with 'new' from similar objects are not equal
myEnum1=new Enum({'A':1, 'B':2, 'C':4});
myEnum2=new Enum({'A':1, 'B':2, 'C':4});
myEnum1 == myEnum2 //=> false
myEnum1.A == myEnum2.A //=> false
myEnum1.A.value == myEnum2.A.value //=> true

//This enum object has no properties other than those defined during its creation. Existing Data is 'Persistent' and preserves the original version
myEnum.B.value; //=> 2
myEnum.B = 5; //=> Throws TypeError
delete myEnum.B; //=> false
myEnum.D = 6; //=> doesn't add to the enum object, silently ignores
myEnum.D; // undefined

//Try to define new property throws TypeError
Object.defineProperty(myEnum, D, {value:6, writable:false, enumerable:true});
//=>TypeError: Cannot define property:D, object is not extensible.