I am currently attempting to populate an array (which is an attribute in a Mongo Model) with items received from a request. I iterate through these items to check if they already exist in the database, and if not, I create a new Item and attempt to save it. Although I am using promises to manage this process, I am puzzled as to why the array turns out empty even after all promises have been fulfilled.
var q = require('q');
var items_to_get = ['1', '2', '3']; // example array
var trans = new Transaction({
items : []
});
var promises = [];
for (var i = 0; i < items_to_get.length; i++) {
var ith = i;
var deferred = q.defer();
Item.findOne({simcode: items_to_get[ith]}, function(err, item) {
trans.items.push(item);
deferred.resolve(item);
});
promises.push(deferred);
};
q.allSettled(promises).then(function(result) {
console.log(trans.items);
trans.save();
}
UPDATE Issue Resolved: Modified code below, inspired by http://jsbin.com/bufecilame/1/edit?html,js,output .. credits to @macqm
var items_to_get = ['1', '2', '3'];
var promises = [];
items_to_get.forEach(item) {
upsertItem(item);
}
q.allSettled(promises).then(function(result) {
result.forEach(function(res) {
if (res.state === "fulfilled") {
trans.items.push(res.value);
}
});
trans.save();
promises = [];
}
function upsertItem(item) {
var deferred = q.defer();
Item.findOne({simcode: item}, function(err, item) {
deferred.resolve(item);
});
promises.push(deferred);
}