Node.js Async only doing one callback

Question

I'm just doing my first bit of Node async stuff, I wanted to do two queries to a DB and then print the results one after the other, my code is as follows:

console.log(req.query);

function logAllThings(err,things){
    if (err){
        console.log(err);
    } else {
        console.log(things);
    };
};


async.parallel([
    function(callback) { //This is the first task, and callback is its callback task
        Event.find({}, function(err, events) {
            logAllThings(err,events);
        });
    },
    function(callback) { //This is the second task, and callback is its callback task
        Organisation.find({}, function(err,organisations) {
            logAllThings(err,organisations);
        }); //Since we don't do anything interesting in db.save()'s callback, we might as well just pass in the task callback 
    }
], function(err) { //This is the final callback
    console.log('Both should now be printed out');
});

The issue I have is that the second function (the one that returns organisations) prints them fine. However the one that is meant to return events simply does not and returns {} despite the fact I know the query works as I've tested it elsewhere.

Any help would be appreciated

Thanks

Answer 1

You have to call the callback function passed to each of your waterfall functions, otherwise it won't know when it's finished. Try this:

async.parallel([
    function(callback) { //This is the first task, and callback is its callback task
        Event.find({}, function(err, events) {
            if (err) return callback(err);
            logAllThings(err,events);
            callback();
        });
    },
    function(callback) { //This is the second task, and callback is its callback task
        Organisation.find({}, function(err,organisations) {
            if (err) return callback(err);
            logAllThings(err,organisations);
            callback();
        }); //Since we don't do anything interesting in db.save()'s callback, we might as well just pass in the task callback 
    }
], function(err) { //This is the final callback
    console.log('Both should now be printed out');
});