带有 Bluebird Promise 的 SailsJS 水线 [英] SailsJS Waterline with Bluebird Promises

问题描述

当使用水线 ORM 时，如果我想使用默认提供的 bluebird promise api，如何将处理传递回控制器.

When using the waterline ORM, if I want to consume the bluebird promise api thats shipped by default how to I pass the processing back to the controller.

代码如下:

module.exports = {
    //Authenticate
    auth: function (req, res) {
        user = req.allParams();
        //Authenticate
        User.authenticate(user, function (response) {
            console.log(response);
            if (response == true) {
                res.send('Authenticated');
            } else {
                res.send('Failed');
            }
        });
    }
};


module.exports = {
    // Attributes

    // Authenticate a user
    authenticate: function (req, cb) {
        User.findOne({
            username: req.username
        })
        .then(function (user) {
            var bcrypt = require('bcrypt');
            // check for the password
            bcrypt.compare(req.password, user.password, function (err, res) {
                console.log(res);
                if (res == true) {
                    cb(true);
                } else {
                    cb(false);
                }
            });
        })
        .catch(function (e) {
            console.log(e);
        });
    }
};

我只是想实现一个身份验证功能.业务逻辑是直截了当的.我感到困惑的是请求流如何从那时起传递回控制器.如果我尝试返回响应，承诺不会响应，但执行 cb(value) 有效.

I am simply trying to implement a authentication function. The business logic is straight forward. What I am confused of is how the request flow is handed back to the controller since. The promise doesn't respond if I try to return a response, but doing a cb(value) works.

推荐答案

使用 Promise 的关键是永远不要打破链条.承诺链取决于每一步，要么返回承诺或值，要么抛出错误.

The key to working with promises is to never break the chain. A promise chain depends on every step either returning a promise or a value, or throwing an error.

以下是您的代码的重写.请注意

The following is a rewrite of your code. Note that

• 路径中的每个回调都返回一些东西，每个函数都返回它所使用的承诺链(甚至 .auth()；它在某些时候可能有用)
• 我使用 BlueBird 的 .promisifyAll() 使 bcrypt 一起玩
• 通过使 username 和 password 参数显式，我已将 .authenticate() 与您的请求/响应基础结构分离.这样可以更轻松地重复使用.

• Every callback in the path returns something and every function returns the promise chain it works with (even .auth(); it might be useful at some point)
• I've used BlueBird's .promisifyAll() to make bcrypt play along
• I've decoupled .authenticate() from your request/response infrastructure by making the username and password arguments explicit. This way it can be reused more easily.

所以现在我们有了(不是 100% 测试，我没有费心安装水线):

So now we have (not 100% tested, I did not bother installing waterline):

module.exports = {
    // authenticate the login request
    auth: function (req, res) {
        var params = req.allParams();
        return User.authenticate(params.username, params.password)
        .then(function () {
            res.send('Authenticated');
        })
        .fail(function (reason) {
            res.send('Failed (' + reason + ')');
        });
    }
};

和

var Promise = require("bluebird");
var bcrypt = Promise.promisifyAll(require('bcrypt'));

module.exports = {
    // check a username/password combination
    authenticate: function (username, password) {
        return User.findOne({
            username: username
        })
        .then(function (user) {
            return bcrypt.compareAsync(password, user.password)
        })
        .catch(function (err) {
            // catch any exception problem up to this point
            console.log("Serious problem during authentication", err);
            return false;
        })
        .then(function (result) {
            // turn `false` into an actual error and
            // send a less revealing error message to the client
            if (result === true) {
                return true;
            } else {
                throw new Error("username or password do not match");
            }
        });
    }
};

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