class-utils

What is class-utils?

The class-utils npm package provides utilities for working with ES6 classes and prototype functions. It includes methods for adding static and prototype methods, implementing mixins, and other class-related utilities.

What are class-utils's main functionalities?

Adding static methods

This feature allows you to add static methods to a class. The code sample demonstrates adding a static method called 'staticMethod' to 'MyClass' using class-utils.

const cu = require('class-utils');
class MyClass {}
cu.static(MyClass, { staticMethod: function() { return 'Static method'; } });
console.log(MyClass.staticMethod());

Adding prototype methods

This feature enables the addition of prototype methods to a class. The example shows how to add an instance method called 'instanceMethod' to 'MyClass' using class-utils.

const cu = require('class-utils');
class MyClass {}
cu.proto(MyClass, { instanceMethod: function() { return 'Instance method'; } });
let obj = new MyClass();
console.log(obj.instanceMethod());

Implementing mixins

This feature supports the implementation of mixins to extend class functionalities. The code sample illustrates adding a mixin method called 'mixinMethod' to 'MyClass' using a mixin function.

const cu = require('class-utils');
function mixin(source) { source.mixinMethod = function() { return 'Mixin method'; }; }
class MyClass {}
cu.mixin(MyClass, mixin);
let obj = new MyClass();
console.log(obj.mixinMethod());

Other packages similar to class-utils

core-decorators

core-decorators offer decorators for classes and properties, similar to class-utils but using the decorator pattern. It provides a more modern syntax and is often preferred in environments that support decorators.

mixin-decorator

mixin-decorator is similar to class-utils in providing mixin functionalities but does so using ES7 decorators, which can be more intuitive and less verbose for developers familiar with the decorator pattern.

README

class-utils

Utils for working with JavaScript classes and prototype methods.

• Install
• Usage
• API
• Related projects
• Running tests
• Contributing
• Author
• License

(Table of contents generated by verb)

Install

Install with npm

$ npm i class-utils --save

Usage

var cu = require('class-utils');

API

.has

Returns true if an array has any of the given elements, or an object has any of the give keys.

Params

• obj {Object}
• val {String|Array}
• returns {Boolean}

Example

cu.has(['a', 'b', 'c'], 'c');
//=> true

cu.has(['a', 'b', 'c'], ['c', 'z']);
//=> true

cu.has({a: 'b', c: 'd'}, ['c', 'z']);
//=> true

.hasAll

Returns true if an array or object has all of the given values.

Params

• val {Object|Array}
• values {String|Array}
• returns {Boolean}

Example

cu.hasAll(['a', 'b', 'c'], 'c');
//=> true

cu.hasAll(['a', 'b', 'c'], ['c', 'z']);
//=> false

cu.hasAll({a: 'b', c: 'd'}, ['c', 'z']);
//=> false

.arrayify

Cast the given value to an array.

Params

• val {String|Array}
• returns {Array}

Example

cu.arrayify('foo');
//=> ['foo']

cu.arrayify(['foo']);
//=> ['foo']

.hasConstructor

Returns true if a value has a contructor

Params

• value {Object}
• returns {Boolean}

Example

cu.hasConstructor({});
//=> true

cu.hasConstructor(Object.create(null));
//=> false

.nativeKeys

Get the native ownPropertyNames from the constructor of the given object. An empty array is returned if the object does not have a constructor.

Params

• obj {Object}: Object that has a constructor.
• returns {Array}: Array of keys.

Example

cu.nativeKeys({a: 'b', b: 'c', c: 'd'})
//=> ['a', 'b', 'c']

cu.nativeKeys(function(){})
//=> ['length', 'caller']

.getDescriptor

Returns property descriptor key if it's an "own" property of the given object.

Params

• obj {Object}
• key {String}
• returns {Object}: Returns descriptor key

Example

function App() {}
Object.defineProperty(App.prototype, 'count', {
  get: function() {
    return Object.keys(this).length;
  }
});
cu.getDescriptor(App.prototype, 'count');
// returns:
// {
//   get: [Function],
//   set: undefined,
//   enumerable: false,
//   configurable: false
// }

.copyDescriptor

Copy a descriptor from one object to another.

Params

• receiver {Object}
• provider {Object}
• name {String}
• returns {Object}

Example

function App() {}
Object.defineProperty(App.prototype, 'count', {
  get: function() {
    return Object.keys(this).length;
  }
});
var obj = {};
cu.copyDescriptor(obj, App.prototype, 'count');

.copy

Copy static properties, prototype properties, and descriptors from one object to another.

Params

• receiver {Object}
• provider {Object}
• omit {String|Array}: One or more properties to omit
• returns {Object}

.inherit

Inherit the static properties, prototype properties, and descriptors from of an object.

Params

• receiver {Object}
• provider {Object}
• omit {String|Array}: One or more properties to omit
• returns {Object}

.extend

Returns a function for extending the static properties, prototype properties, and descriptors from the Parent constructor onto Child constructors.

Params

• Parent {Function}: Parent ctor
• Child {Function}: Child ctor
• proto {Object}: Optionally pass additional prototype properties to inherit.
• returns {Object}

Example

var extend = cu.extend(Parent);
Parent.extend(Child);

// optional methods
Parent.extend(Child, {
  foo: function() {},
  bar: function() {}
});

Related projects

• define-property: Define a non-enumerable property on an object. | homepage
• delegate-properties: Deep-clone properties from one object to another and make them non-enumerable, or make existing properties… more | homepage
• is-descriptor: Returns true if a value has the characteristics of a valid JavaScript descriptor. Works for… more | homepage

Running tests

Install dev dependencies:

$ npm i -d && npm test

Contributing

Pull requests and stars are always welcome. For bugs and feature requests, please create an issue.

Author

Jon Schlinkert

• github/jonschlinkert
• twitter/jonschlinkert

License

Copyright © 2015 Jon Schlinkert Released under the MIT license.

---

This file was generated by verb-cli on October 01, 2015.