I try to make a list with products that I send to the client, but the res.send gets executed before the loop has finished. Do you have any suggestions? Async/await doesn't seem to work.

Here is my code:

const Outfits = require("../models/Outfits");
const Products = require("../models/Products");

module.exports = (req, res) => {
    Outfits.find({ outfitId: req.params.id }, async (error1, result) => {
        if (error1) {
            res.status(400).json({
                status: "fail",
            });
        } else {
            let productIds = result[0].productIds;
            let productList = [];
            for (let i = 0; i < productIds.length; i  ) {
                await Products.find({ id: productIds[i] })
                    .then((product) => {
                        console.log(product);
                        productList.push(product);
                    })
                    .catch((error2) => {
                        res.status(400).json({
                            status: "fail",
                        });
                    });
            }
            console.log(productList);
            res.status(200).json({
                status: "success",
                body: productList,
            });
        }
    });
};

Thank you very much!

CodePudding user response：

In order to have multiple asynchrone tasks executed at once, a clean way is to use a Promise.all and pass an array of your asynchrone tasks. Like so :

const Outfits = require("../models/Outfits");
const Products = require("../models/Products");

module.exports = (req, res) => {
    Outfits.find({ outfitId: req.params.id }, async (error1, result) => {
        if (error1) {
            res.status(400).json({
                status: "fail",
            });
        } else {
            let productIds = result[0].productIds;
            
            //
            const productList = await Promise.all(
                 productIds.map((id) => Products.findById(id))
            );
           
            console.log(productList);
            res.status(200).json({
                status: "success",
                body: productList,
            });
        }
    });
};

CodePudding user response：

You need to call await on the Products.find function like this

for (let i = 0; i < productIds.length; i  ) {
  try {
    const product = await Products.find({ id: productIds[i] }).exec()
    console.log(product);
    productList.push(product);
  } catch (error) {
    res.status(400).json({
      status: "fail",
    });
  }
}

CodePudding user response：

Do you have any suggestions? Async/await doesn't seem to work

The async/await in your code does not work it is because of the function mongoose gives you.

1. callback style

   // finds the outfit and passes the outfit to the callback

   Outfits.find({ outfitId: req.params.id }, async (error1, outfit) => {

   // your other logic

   })

2. async/await style

   // finds the outfit and returns

   const outfit = await Outfits.find({outfitId: req.params.id }).exec();

Assuming you retrieve array of product id this way

let productIds = result[0].productIds;

const products = await Promise.all(

productIds.map((productId)=>{

   return Products.findById(productId)

}

)

This should retrieve you the list of products

This is my first time answering a question hence the try hard answer haha :).