How to wait for a promise to be resolved?

javascript node.js promise q
sinθ picture sinθ · Jun 11, 2014 · Viewed 49.9k times · Source

I'm dealing with a NodeJs framework that requires a certain function to be synchronous, but I need to retrieve a value that can only be accessed asynchronously. In a perfect world, I would be able to return a promise, but I can't.

As a quick-and-dirty solution, I created the following method:

exports.synchronizePromise = function(promise) {
    var value;
    promise.then(function(promiseValue) {
        value = promiseValue;
    });
    while (!value) {} // Wait for promise to resolve
    console.log("DONE: " + value); // Never reached
    return value;
};

But I get an error. Is there any way to accomplish what I need?

Answer

tcurdt picture tcurdt · Mar 15, 2016

Given that node is by default only single threaded there isn't really an easy way to solve this. There is one though. Bases on generators/fibers you can add a sort of concurrent execution to node. There is a waitfor implementation based on that.

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