arc-object

An object convenience subclass for javascript (ES6)

Install

$ npm install arc-object --save

Features

• forEach() with break functionality
• fauxrray like functions
  • ksort()
  • keys()
  • count()
  • first()
  • last()
  • shift()
  • pop()
  • reduce()
  • map()
  • filter()
• deepGet() to safely look for and return a value from a nested structure
• native convenience binding (if desired)
• freeze() and deepFreeze() (object freezing)
• failure safe object instantiation checking
• duck typing interfaces of two objects

Basic Usage

The following example creates a new ArcObject, filters out false/empty/null values, keysorts, and breaks on a specific value

var ArcObject = require('arc-object');
var alpha = new ArcObject({z:'z',x:false,y:'aardvark',a:'a',b:undefined,c:'c'});

//Filter out false/undefined vals
alpha.filter(val => !!val);

//Key sort. Now internally ordered as {a:'a',c:'c',y:'aardvark',z:'z'}
alpha.ksort();

//Iterate
alpha.forEach(function(_val,_key){
    if(_val === 'aardvark'){
        //Break when we hit aardvark
        return false;
    }
});

API

new ArcObject(Object)

Create a new ArcObject object. Requires new

.forEach(callback:Function[, thisContext:Object])

Loop over an object index, calling callback each iteration. Break when false is explicitly returned.

callback is a required function that is called with 3 arguments passed in

• value: the value of the current iteration
• key: the index key of the current iteration
• reference: the object reference being iterated over

thisContext is an optional object that will be available inside of the callback as this if set, otherwise defaulting to the original object.

//Example of breaking each
var users = new ArcObject({'a':'aardvark','b':'brad','c':'documents are boring'});
users.forEach(function(_v,_k){
    if(_v === 'brad'){
        return false;
    }
});

###.map(callback:Function,[,asArray:Boolean]) Faux map for objects. Iterate over the values in the object, and return an array for each entry in the object (or a new object)

By default, this returns a new array with a return value for each item in the object being iterated over

//Example of map (default)
const numbers = new ArcObject({'a': 1, 'b': 2, 'c': 3});
const doubledValues = numbers.map((number) => number+number)
//doubledValues contains [2,4,6]

If asArray is set to false, a new object will be created with the same keys as the object mapped, but new values

//Example of map (default)
const numbers = new ArcObject({a: 1, b: 2, c: 3});
const doubledValues = numbers.map((number) => number+number, false)
//doubledValues contains {a:2,b:4,c:6}

.reduce(callback:Function,returnArg:Mixed[,falseBreak:Boolean])

Faux reduce for objects. Iterate over the object, and return a single value.

By default, returning false breaks the iteration, but this can be optionally switched off by passing in false as the third argument.

//Example of reduce
var users = new ArcObject({'a':'aardvark','b':'brad','c':'documents are boring','d':'Andy'});
var aUsers = users.reduce(function(_aUsers,_val,_key){
    //3rd argument is key, not using it in this example
    if(_val.charAt(0) === 'a'){
        _aUsers.push(_val);
    }
    return _aUsers;
},[]);

//aUsers contains ['aardvark','Andy']

.ksort()

Rebuild an object by keys (alphabetical)

var alpha = new ArcObject({c:'c',b:'b',a,'a'});
alpha.ksort(); //Now {a:'a',b:'b',c:'c'}

.first()

Get whatever value is currently at the first pointer in the object index

var alpha = new ArcObject({a:'a',z:'z'});
alpha.first(); //return 'a'

.last()

Get whatever value is currently at the last pointer in the object index

var alpha = new ArcObject({a:'a',z:'z'});
alpha.first(); //return 'z'

.shift()

Remove and return whatever value is currently at the first pointer in the object index

var alpha = new ArcObject({a:'a',z:'z'});
alpha.shift(); //return 'a' and remove 'a' from alpha object

.pop()

Remove and return whatever value is currently at the last pointer in the object index

var alpha = new ArcObject({a:'a',z:'z'});
alpha.pop(); //return 'z' and remove 'z' from alpha object

.count()

Return the current length of the object utilizing Object.keys(this).length

var alpha = new ArcObject({a:'a',z:'z'});
alpha.count(); //return 2

.keys()

Return an ArcArray array of the current object keys

var alpha = new ArcObject({a:'a',z:'z'});
alpha.keys(); //['a','z'] (ArcArray)

.freeze()

Turn object immutable (shallow)

var alpha = new ArcObject({a:'a',z:'z'});
alpha.freeze();
alpha.a = 'aardvark'; //This will fail to set the a property

.deepFreeze()

Turn object immutable (deep)

var alpha = new ArcObject({a:'a',z:{x:'x'}});
alpha.deepFreeze();
alpha.z.x = 'aardvark'; //This will fail to set the a property

.constant(key:Mixed,val:Mixed[,enumerable:Boolean])

Alias of static ArcObject.defineConstant()

.filter(callback:Function)

Remove indexes from object based on callback return of false

//Example of filter
var alpha = new ArcObject({a:true,b:false,z:undefined});
alpha.filter(val => !!val); //Object is reduced to {a:true}

ArcObject.deepGet(...args)

This is method that can be used to safely fetch a nested key path inside of an object. Returns the value found, or undefined

//An descriptive object with sub data
var user = new ArcObject({'details':{'id':750}});
user.deepGet('details','id'); //Returns 750
user.deepGet('details','name'); //Returns undefined

ArcObject.duckType(primary:Object,duck:Object)

Compare two objects to see if the duck object has the same properties bound as functions as the primary object

//Example class
class Test{
    getSomething(){}
}

//Two seperate instantiations
var primary = new Test;
primary.id = "one thing";

var duck = new Test;
duck.id = "another thing";

//Comparison
(primary == duck); //false
(primary === duck); //false
ArcObject.duckCheck(primary,duck); //true

//Change the interface on the primary, so the duck no longer matches
primary.newFunc = function(){};
ArcObject.duckCheck(primary,duck); //false

//But reverse the order...
ArcObject.duckCheck(duck,primary); //true (because we are not comparing if the interfaces are identical, only if the secondary has the same interface as the primary)

ArcObject.nativeBind()

this is a static method that binds a method to the native global object property that transforms an object into an ArcObject object. This has a global effect and should be used carefully.

ArcObject.nativeBind();
var users = {
    id1:'aaa',
    id2:'bbb',
    id3:'ccc'
}.arc(); //This returns an ArcObject object

ArcObject.defineConstant(obj:Object,key:Mixed,val:Mixed [,enumerable:Boolean])

This is a convenience static method that does the following:

Object.defineProperty(obj, key, {
    value: val,
    writable : false,
    enumerable : (enumerable === false ? false : true),
    configurable : false
});

Testing

npm test