node-promise 介绍
node-promise 在 Node.js 平台上提供了完整的 Promises
的实现。
The node-promise module features a promise implementation with:
- Chainable promises
- Promises throw errors if an error handler is not provided
- Commonjs promise proposal [1] compliant
- Immutable once fulfilled to reduce possible side-effects
- Promises can be used securely (as separate resolver/promise pairs in ocap situations)
- Backwards compatibility where possible (addCallback, addErrback, emitSuccess, and emitError should still behave as expected)
Utility functions, including:
- when() - normalization of sync (normal values) and async (promises)
- all() - Create a promise that accumulate multiple concurrent promises
- first() - Find the first promise to be fulfilled in a group of promises
- seq() - Sequentially execute a set of promise returning functions
- delay() - Returns a promise that is fulfilled after a given amount of time
- execute() - Executes a function that takes a callback and returns a promise (thank you Benjamin Thomas for providing this)
示例代码：
var Promise = require("promise").Promise;
var promise = new Promise();
asyncoperation(function(){
Promise.resolve("succesful result");
});
promise -> given to the consumer