How Do I Properly Issue Response To Post When Waiting For Async Method To Complete?

Here's the setup in a module. See, esp., comments marked by ****: exports.saveWall = function (req, res) { var status; mongoClient.connect(connectionString, function (err,

Solution 1:

Even though you solved your scope issue (which is awesome), nesting callbacks can get kind of tricky quickly (as you saw). A good way to deal with this is to use promises. The two main packages for promises are Q and Bluebird (with Bluebird being my favorite).

You can also use a package that has already promise-ified mongo calls for you, like promised-mongo

Once you have that all set up, it's just a matter of chaining .then for successive steps, and then sending your response when the promise is resolved.

For a specific example, check out this answer and see if that helps.

Solution 2:

Ugh...

It turns out my issue was that "res" was defined both here:

exports.saveWall = function (req, res) {

...and here:

db.collection(pictureWallsCollectionName).insert(..., 
        function(err, res) {

...so it turns out I could call "res" all along, I was just trying to call the wrong "res" because it got redefined.

On a side note, f*** you, javascript!