CODEWITHSUNDEEP
javascriptnode.jsasynchronouscallback
RainingChain
RainingChain

Reputation: 7782

Array of Callback Functions

What I'm doing atm:

function1(function(){
    function2(function(){
        function3(function(){
            function4();
        }
    }
}

Is there an easier way to do it?

miracleFunction([function1,function2,function3,function4]);

miracleFunction = function(array){
    ???
}

Upvotes: 1

Views: 93

Answers (3)

Chris
Chris

Reputation: 1611

Instead of going deep into callbacks, break them up into easily understandable functions:

function GetUserData(id, callback) {
    // db queries, etc
    connection.query('...get user info...', function (err, results) {
        connection.query('...get user related whatnot...', function (err, results) {
            callback ();
        });
    });
}

connection.query('...load page data...', function (err, results) {
    GetUserData( function () {
        res.render('page.ejs', ... );
    });
});

You could even break the more used functions off into a module so you don't have too much clutter in your code. The async package looks nice, but to me, personally, I like to see the flow. Always up to programmer's preference.

Upvotes: 0

Timothée Groleau
Timothée Groleau

Reputation: 1960

Take a look at promises which also allow you to handle errors very nicely.

Q is especially nice, and support just your use case. Direct link here: https://github.com/kriskowal/q#sequences

Upvotes: 0

icktoofay
icktoofay

Reputation: 129139

Using the async package on npm, you can use an array like that, e.g.:

var async = require('async');
async.series([function1, function2, function3, function4]);

In addition to simply running several asynchronous functions in a series, it also has functions simplifying running asynchronous operations in parallel, mapping an array using an asynchronous function, and various other helpful combinators.

Upvotes: 3

Related Questions