ezobjects

EZ Objects v0.6.0

Under development, but completely useable.

Principles of Operation

This module, when required, is a function that takes a single object argument. At present, that object can have the following keys:

• name - A string containing the name of the desired class object (required)
• extends - An object that you wish the class to extend from (optional, note this is the class itself, not the name)
• fields - An array of fields (properties) that the class will have getters/setters/initialization for (optional)

Each field in the array is an object that can have the following keys:

• name - The name of the field (required)
• type - The type of the field (required, can be string, int, float, boolean, Array, or any other object name)
• default - The default initialized value (optional)

Default defaults are:

• string - ''
• int - 0
• float - 0
• boolean - false
• Array - []
• Any others - null

Note that the created objects are added to the global space, being global (node) or window (browser), though you'll have to browserify or equivalent to use in browser. Like normal classes, they can have other properties/methods added externally using the prototype, though note that if you want external prototype-added properties to be initialized, you'll have to rewrite the init() function manually. Alternatively, you can just extend the class and init the parent with super. See examples below.

Example

const ezobjects = require('ezobjects');

/** 
 * Create a customized object on the global (node) or window (browser) namespace, complete with 
 * constructor/init/getters/setters with strict type checking, TypeError thrown if invalid type.
 */
ezobjects({
  name: 'DatabaseRecord',
  fields: [
    { name: 'id', type: 'int' }
  ]
});

/** Create another customized object that extends the first one */
ezobjects({
  name: 'Person',
  extends: DatabaseRecord,
  fields: [
    { name: 'firstName', type: 'string' },
    { name: 'lastName', type: 'string' },
    { name: 'checkingBalance', type: 'float' },
    { name: 'permissions', type: 'Array' },
    { name: 'favoriteDay', type: 'Date' }
  ]
});

/** Example of the extended object newly instansiated */
const a = new Person();

console.log(a);

/** Example of the extended object instansiated and initialized using object passed to constructor */
const b = new Person({
  id: 1,
  firstName: 'Rich',
  lastName: 'Lowe',
  checkingBalance: 4.87,
  permissions: [1, 2, 3],
  favoriteDay: new Date('01-01-2018')
});

console.log(b);

/** Example of the extended object instansiated, then loaded with data using setter methods */
const c = new Person();

c.id(2);
c.firstName('Bert');
c.lastName('Reynolds');
c.checkingBalance(91425518.32);
c.permissions([1, 4]);
c.favoriteDay(new Date('06-01-2017'));

console.log(c);

/** Example of the extended object's properties being accessed using getter methods */
console.log(`ID: ${c.id()}`);
console.log(`First Name: ${c.firstName()}`);
console.log(`Last Name: ${c.lastName()}`);
console.log(`Checking Balance: $${c.checkingBalance()}`);
console.log(`Permissions: ${c.permissions().join(`, `)}`);
console.log(`Favorite Day: ${c.favoriteDay().toString()}`);

/** Adding capability to the generated object's prototype */
DatabaseRecord.prototype.table = function (arg) {
  if ( arg === undefined )
    return this._table;
  
  this._table = arg;
};

/** Yuck, now I have to manually override the init() call */
DatabaseRecord.prototype.init = function (data = {}) {
  this.id(data.id || 0);
  this.table(data.table || '');
};

const d = new DatabaseRecord();

console.log(d);

/** These objects can be extended */
class DatabaseRecord2 extends DatabaseRecord {
  constructor(data = {}) {
    super(data);
  }

  init(data = {}) {
    super.init(data);
    this.test('Test');
  }

  test(arg) {
    if ( arg === undefined )
      return this._test;

    this._test = arg;
  }
}

const e = new DatabaseRecord2();

console.log(e);

Example Output

Person {
  _id: 0,
  _firstName: '',
  _lastName: '',
  _checkingBalance: 0,
  _permissions: [],
  _favoriteDay: null }
Person {
  _id: 1,
  _firstName: 'Rich',
  _lastName: 'Lowe',
  _checkingBalance: 4.87,
  _permissions: [ 1, 2, 3 ],
  _favoriteDay: 2018-01-01T06:00:00.000Z }
Person {
  _id: 2,
  _firstName: 'Bert',
  _lastName: 'Reynolds',
  _checkingBalance: 91425518.32,
  _permissions: [ 1, 4 ],
  _favoriteDay: 2017-06-01T05:00:00.000Z }
ID: 2
First Name: Bert
Last Name: Reynolds
Checking Balance: $91425518.32
Permissions: 1, 4
Favorite Day: Thu Jun 01 2017 00:00:00 GMT-0500 (CDT)
DatabaseRecord { _id: 0, _table: '' }
DatabaseRecord2 { _id: 0, _table: '', _test: 'Test' }