Question

function DatabaseConnect(req, res) {...}
function CreateNewUser(req, res) {...}

function Go (app, req, res) {

    // If is POST on this URL run this function
    var firstFunction = app.post('/admin/svc/DB', function(res, req) { 
        DatabaseConnect(req, res) 
    });

    // If is POST on this URL run this function
    var secondFunction = app.post('/admin/svc/CREATE', function(res, req) { 
        CreateNewUser(req, res) 
    });

    // Run first all callbacks and after render page
    function Render(firstMe, afterMe) {
        firstMe();
        afterMe();
        app.render('screen');
    }

    Render(firstFunction, secondFunction);

}

Go();

如何运行更多功能asyn。和Render（）毕竟？

如果该URI上的ist POST，则调用APP.POST。

Answer 1

根据您的需要，这里有各种不同的方法。如果你只关心完成一定数量的异步函数，一个常见的模式是基本上保持计数并在你完成后触发afterAll()方法：

var count = 0,
    target = 2; // the number of async functions you're running

function afterAll() {
    if (++count === target) {
        // do something
    }
}

doAsync1(function() {
    // some stuff
    afterAll();
});

doAsync2(function() {
    // some stuff
    afterAll();
});

Underscore在此处提供了一些有用的实用程序，包括_.after：

var asyncMethods = [doAsync1, doAsync2, doAsync3],
    // set up the callback to only run on invocation #3
    complete = _.after(asyncMethods.length, function() {
        // do stuff
    });
// run all the methods
asyncMethods.forEach(function(method) {
    // this assumes each method takes a callback
    method(complete);
});

在Express / NodeJs中更好的回调Javascript代码

1 个答案: