# deferred-lib

**Repository Path**: lanfei/deferred-lib

## Basic Information

- **Project Name**: deferred-lib
- **Description**: 一个轻量级的 Deferred/Promise 接口实现。
- **Primary Language**: JavaScript
- **License**: Not specified
- **Default Branch**: master
- **Homepage**: https://nodei.co/npm/deferred-lib
- **GVP Project**: No

## Statistics

- **Stars**: 2
- **Forks**: 0
- **Created**: 2016-07-19
- **Last Updated**: 2024-04-18

## Categories & Tags

**Categories**: javascript-toolkits

**Tags**: None

## README

# Deferred

A lightweight implementation of Deferred/Promise.

[![NPM](https://nodei.co/npm/deferred-lib.png?downloads=true&downloadRank=true&stars=true)](https://nodei.co/npm/deferred-lib)

## Installation

### Node

```bash
$ npm install deferred-lib
```

### Browser

```html
<script src="js/deferred.min.js"></script>
```

## Usage

```js
// Usage 1
// Declare the deferred instance and use it.
function countdown1() {
	var deferred = new Deferred();
	var i = 5;
	var timer = setInterval(function () {
		deferred.notify(i);
		if (i-- === 0) {
			deferred.resolve('Hi');
			clearInterval(timer);
		}
	}, 300);
	return deferred.promise();
}

countdown1().progress(function (step) {
	console.log('countdown1', step);
}).done(function () {
	console.log('countdown1 done');
});


// Usage 2
// Use `Deferred(fn)` and get the deferred instance with `this` context.
function countdown2() {
	var self = this;
	var i = 5;
	var timer = setInterval(function () {
		self.notify(i);
		if (i-- === 0) {
			self.resolve('Hi');
			clearInterval(timer);
		}
	}, 300);
}

Deferred(countdown2).progress(function (step) {
	console.log('countdown2', step);
}).done(function () {
	console.log('countdown2 done');
});
```

**See `examples` directory for more usages.**