Return when .each is completed - arrays

Question

Promise.try(function (){
return Promise.all(splitup); // [Show, me, stocks, for, Google, and, Microsoft]
}).each(function (item) { // Looping through entities, [Show] [me] [stocks] ...
alchemyapi.entities('text', item, { 'sentiment' : 1}, function (response) {
if(response.entities) { // An entity is found, ex. Microsoft
if(response.entities[0].type === "Company") {
requestBody.push(item);
console.log("Item was found, added " + item);
} else {
console.log(item + " Is not a company");
}
} else { // no entity found for that one word
console.log("No entity found for " + item);
}
});
}).then(function (response) {
// send requestBody when loop is completed.
});
I start by returning an array of strings splitup so I can loop through each element on line 3.
Let's say the splitup array looks like: [Apple, And, Mexico]
Apple is a company, so if(response.entities) returns true, it then checks the JSON response to see if it is a company, that statement returns true and It's added to the new requestBody array I'm building up.
Next, the word 'And' returns false on if(response.entities) so It goes to the else statement.
Next, let's pick Mexico, It'll return true for if(response.entities) but return false on if(response.entities[0].type === "Company")
My question is, I'd like to return the new requestBody array when It has completed looping through each item, but I'm not entirely sure how I can tell when the loop is completed, and when to return requestBody

Answer 1

You need to use Promise.filter instead of Promise.each. Promise.filter filters the given array to another using filterer function passed to it.
So when you encounter a company ('Apple') you resolve with its value, if its anything else ('Mexico' and 'And') you resolve with false.
Promise.filter(splitup, function (item) { // Looping through entities, [Show] [me] [stocks] ...
return new Promise(function(resolve, reject) {
alchemyapi.entities('text', item, { 'sentiment' : 1}, function (response) {
if(response.entities) { // An entity is found, ex. Microsoft
if(response.entities[0].type === "Company") {
console.log("Item was found, added " + item);
return resolve(item);
} else {
console.log(item + " Is not a company");
return reject(false);
}
} else { // no entity found for that one word
console.log("No entity found for " + item);
return reject(false);
}
});
});
}).then(function (requestBody) {
// send requestBody when loop is completed.
});

Answer 2

Ok too late :). Here was my result:
var alchemyapi = require('alchemy-api');
var Promise = require('bluebird');
var alchemyapi = new alchemyapi(<YOUR_KEY>);
var test = ['Microsoft', 'and', 'Apple'];
Promise.filter(test, function(item) {
return getCompanyName(item).then(function(){
return true;
}, function(reason) {
console.log(reason.message);
return false;
});
}).then(function(requestBody){
console.log(requestBody);
});
function getCompanyName(item) {
return new Promise(function(resolve, reject) {
alchemyapi.entities(item, {sentiment: 1}, function (err, response) {
if (err) reject(err);
if (response.entities.length > 0) { // An entity is found, ex. Microsoft
if (response.entities[0].type === "Company") {
resolve(item);
} else {
reject(new Error(item + " Is not a company"));
}
} else { // no entity found for that one word
reject(new Error("No entity found for " + item));
}
});
});
}