Waterfall -> Parallel

[ghost]

I want to run 2 functions in waterfall then pass the value from the last one to 3 functions in parallel.

I have been struggling with waterfall + parallel without any results.

Is this possible with async somehow?

[caolan]

You probably want something like this:

async.waterfall([
    function (callback) {
        callback(null, 1);
    },
    function (arg, callback) {
        callback(null, arg1 + 1);
    },
    function (arg, callback) {
        async.parallel([
            function () { ... },
            function () { ... },
            function () { ... },
        ], callback);
    }
]);

Hope that helps :)

[ghost]

Yeah it worked!

But one problem when I returned a closure like this:

function printName(name) {
    return function(callback) {
        console.log(arg1);
        console.log(name);
        callback(null, name);
    }
}

async.waterfall([
    function (callback) {
        callback(null, 1);
    },
    function (arg, callback) {
        callback(null, arg1 + 1);
    },
    function (arg, callback) {
        async.parallel([
            printName("Josh"),
            function (callback) { ... },
            function (callback) { ... },
        ], finalCallback);
    }
]);

It said arg1 is not defined because it's in the closure now and not inside async.waterfall().

This forces the code to not stay DRY cause I can't reuse functions.

Is there a way to fix this?

[caolan]

You'll need to pass arg1 as an argument to printName... it looks like that would make sense anyway if you want to reuse printName.