autobind-decorator

What is autobind-decorator?

The `autobind-decorator` npm package provides a decorator for automatically binding methods to their class instance. This is particularly useful in JavaScript and TypeScript classes where you want to ensure that methods retain the correct `this` context, especially when passing them as callbacks.

What are autobind-decorator's main functionalities?

Automatic Method Binding

This feature allows you to automatically bind class methods to the instance of the class. In the example, the `getValue` method is bound to the instance of `MyClass`, ensuring that `this.value` correctly refers to the instance's `value` property even when the method is called as a standalone function.

class MyClass {
  constructor() {
    this.value = 42;
  }

  @autobind
  getValue() {
    return this.value;
  }
}

const instance = new MyClass();
const getValue = instance.getValue;
console.log(getValue()); // 42

Other packages similar to autobind-decorator

core-decorators

The `core-decorators` package provides a collection of decorators, including an `autobind` decorator. It offers a broader set of decorators for various use cases, such as `@debounce`, `@memoize`, and `@readonly`, making it a more versatile choice if you need multiple types of decorators.

lodash-decorators

The `lodash-decorators` package offers a set of decorators based on lodash functions, including an `autobind` decorator. It is useful if you are already using lodash in your project and want to leverage its utility functions in a decorator form.

typescript-decorators

The `typescript-decorators` package provides a set of decorators specifically designed for TypeScript. It includes an `autobind` decorator and other useful decorators for TypeScript development, making it a good choice for TypeScript projects.

README

autobind decorator

A class or method decorator which binds methods to the instance so this is always correct, even when the method is detached.

This is particularly useful for situations like React components, where you often pass methods as event handlers and would otherwise need to .bind(this).

// Before:
<button onClick={ this.handleClick.bind(this) }></button>

// After:
<button onClick={ this.handleClick }></button>

As decorators are a part of future ECMAScript standard they can only be used with transpilers such as Babel.

Note Babel 6 users:

The implementation of the decorator transform is currently on hold as the syntax is not final. If you would like to use this project with Babel 6.0, you may use babel-plugin-transform-decorators-legacy which implement Babel 5 decorator transform for Babel 6.

Installation:

npm install autobind-decorator

Examples:

import autobind from 'autobind-decorator'

class Component {
  constructor(value) {
    this.value = value
  }

  @autobind
  method() {
    return this.value
  }
}

let component = new Component(42)
let method = component.method // .bind(component) isn't needed!
method() // returns 42


// Also usable on the class to bind all methods
@autobind
class Component { }

Alternative

You might want to look at Class instance properties.