NodeJS item was not added on the index of the object?

Question

Now I have a code below which first query the result from vehicle model and then use the results to query for files and collections and at the end of the line in

if (finalFile) {
    var item = "testdatass"
    veh.data[i].FileData = item
    //item was added here when i try to console log
    console.log("veh.data[i].FileData", veh.data[i])
}

On the line above I tried to assign

veh.data[i].FileData = item

But when I check the data which is the veh.data on the final response, the item was not added.

return res.status(200).send({
    message: "success",
    pageNo: pageNo,
    totalRecords: veh.data.length,
    data: veh.data,
    totalPages: totalPages

})

Full Code

let veh = {
  data: []
}


Vehicle.model.count({}, function(err, totalCount) {
  if (err) {
    response = {
      "error": true,
      "message": "Error fetching data"
    }
  }

  Vehicle.model.find(query, {}, pagination).sort(sortOrd + sortType).exec(function(err, vehicle) {

    if (err || !vehicle) {
      res.json({
        message: err
      })
    }

    var totalPages = Math.ceil(totalCount / size)

    veh.data = vehicle

    MongoClient.connect(url, function(err, client) {

      if (err) {
        return res.render('index', {
          title: 'Uploaded Error',
          message: 'MongoClient Connection error',
          error: err.errMsg
        });
      }

      const db = client.db(dbName);
      const collection = db.collection('fs.files');
      const collectionChunks = db.collection('fs.chunks');

      for (let i = 0; i < veh.data.length; i++) {

        let ImageList = veh.data[i].ImageList.split(',')
        let profile_name = ImageList[0].split('/').pop();

        collection.find({
          $and: [{
              $or: [{
                metadata: veh.data[i].VIN
              }]
            },
            {
              $or: [{
                filename: profile_name
              }]
            }
          ]
        }).toArray(function(err, docs) {
          if (err) {
            return res.render('index', {
              title: 'File error',
              message: 'Error finding file',
              error: err.errMsg
            });
          }
          if (!docs || docs.length === 0) {
            return res.render('index', {
              title: 'Download Error',
              message: 'No file found'
            });
          } else {

            for (let i = 0; i < docs.length; i++) {

              collectionChunks.find({
                  files_id: docs[i]._id
                })
                .toArray(function(err, chunks) {
                  if (err) {
                    return res.render('index', {
                      title: 'Download Error',
                      message: 'Error retrieving chunks',
                      error: err.errmsg
                    });
                  }
                  if (!chunks || chunks.length === 0) {
                    return res.render('index', {
                      title: 'Download Error',
                      message: 'No data found'
                    });
                  }

                  let fileData = []

                  for (let i = 0; i < chunks.length; i++) {
                    fileData.push(chunks[i].data.toString('base64'));
                  }

                  let finalFile = 'data:' + docs[0].contentType + ';base64,' +
                    fileData.join('');

                  if (finalFile) {
                    var item = "testdatass"
                    veh.data[i].FileData = item
                  }


                });
            }
          }
        })
      }
    })

//now on the final data the when i check and logged it the item was not added
console.log("Total Vehicle", vehicle.length)

return res.status(200).send({
  message: "success",
  pageNo: pageNo,
  totalRecords: veh.data.length,
  data: veh.data,
  totalPages: totalPages

})

}) })

Result

    vehicle data [ { _id: 5dba69401fe3d41714eafb62,
        DriveType: 'FWD',
        FuelType: 'Gasoline Fuel',
        ImageList:'',
        Options:
         'Traction Control,Stability Control,Front Wheel Drive,Tires - Front All-Season,Tires - Rear All-Season,Aluminum Wheels,Power Steering,4-Wheel Disc Brakes,ABS,Brake Assist,Sun/Moonroof,Generic Sun/Moonroof,Rear Spoiler,Automatic Headlights,Fog Lamps,Heated Mirrors,Power Mirror(s),Privacy Glass,Intermittent Wipers,Variable Speed Intermittent Wipers,Leather Seats,Power Driver Seat,Bucket Seats,Heated Front Seat(s),Driver Adjustable 
    Lumbar,Passenger Adjustable Lumbar,3rd Row Seat,Pass-Through Rear Seat,Floor Mats,Steering Wheel Audio Controls,Adjustable Steering Wheel,Engine Immobilizer,Tire Pressure Monitor,Power Windows,Power Door Locks,Universal Garage Door Opener,Keyless Entry,Cruise Control,Security System,Climate Control,A/C,Rear A/C,Rear Defrost,AM/FM Stereo,CD Changer,CD Player,Satellite Radio,Entertainment System,Power Outlet,Driver Vanity Mirror,Passenger Vanity Mirror,Driver Illuminated Vanity Mirror,Passenger Illuminated Visor Mirror,Rear Reading Lamps,Driver Air Bag,Passenger Air Bag,Front Side Air Bag,Passenger Air Bag Sensor,Front Head Air Bag,Rear Head Air Bag,Child Safety Locks',
        Description: '',
        DateInStock: '7/15/2019',
        Invoice: 3000,
        BookValue: '3686',
        MSRP: 0,
        SellingPrice: 5592,
        Miles: 162111,
        Transmission: 'Automatic',
        EngineDisplacement: '3.5L',
        EngineCylinders: '6',
        InteriorColor: '',
        ExteriorColor: 'Gray',
        Doors: 4,
        ModelNumber: 'YF2867JNW',
        Trim: 'Ex-L',
        Body: 'Sport Utility',
        Model: 'Piloto',
        Make: 'Honda',
        Year: 2007,
        VIN: '5FNYF28677B037628',
        Stock: 'K2501A',
        Type: 'Used',
        __v: 0,
        state: 'published',
        Certified: true } ]

1. You are changing `veh` bit not using it in the response or the console.log after 2. Isn't `Vehicle.model.count` async? Because it seems like it would be, [you shouldn't be using it like that](https://stackoverflow.com/questions/14220321/how-do-i-return-the-response-from-an-asynchronous-call) — VLAZ, Nov 04 '19 at 05:19
can you post your implementation sir ? if what is wrong with my code — Jhon Caylog, Nov 04 '19 at 05:20
can you please once add `console.log("Total Vehicle" , vehicle.length)` exactly below this line? — Sravan, Nov 04 '19 at 05:56
The implementation needs to chunked out into functions by having `async await` or `promise` behavior. The above code will never work. — Sohan, Nov 04 '19 at 06:10
can you please post your answer withan async wait or promise implementation sir ? Sir @Sohan — Jhon Caylog, Nov 04 '19 at 06:11
I will probably post the answer with possible fixes. But I cannot run this on my side. — Sohan, Nov 04 '19 at 06:14
Also, above code is incomplete.. where is `Vehicle.model.count` and `Vehicle.model.find` coming from. Cannot imagine what is running inside functions. Please clear that first — Sohan, Nov 04 '19 at 06:17
var Vehicle = keystone.list('Vehicle'); , it is provided by the keystone framework sir — Jhon Caylog, Nov 04 '19 at 06:18
The issue here is that you're trying to run an **async** operation ***synchronously***. @Sohan is right. You should be using `promises` or `async/ await`. The code you've provided isn't enough for others to figure out what's exactly going on, so you should probably add some more code to your question followed by a solid explanation. Good luck. — Dženis H., Nov 04 '19 at 06:33

score 1 · Answer 1 · answered Nov 04 '19 at 06:31

You can not call mongodb query inside for loop because loop working sync and mongo query run as async so you can not get your desire output.

Here is your full code with solutions

let veh = {
    data: []
}

Vehicle.model.count({}, function (err, totalCount) {
    if (err) {
        response = {
            "error": true,
            "message": "Error fetching data"
        }
    }

    Vehicle.model.find(query, {}, pagination).sort(sortOrd + sortType).exec(function (err, vehicle) {
        if (err || !vehicle) {
            res.json({
                message: err
            })
        }

        var totalPages = Math.ceil(totalCount / size)

        veh.data = vehicle;

        MongoClient.connect(url, function (err, client) {
            if (err) {
                return res.render('index', {
                    title: 'Uploaded Error',
                    message: 'MongoClient Connection error',
                    error: err.errMsg
                });
            }

            const db = client.db(dbName);
            const collection = db.collection('fs.files');
            const collectionChunks = db.collection('fs.chunks');
            const promise = [];
            let ImageList = veh.data[i].ImageList.split(',')
            let profile_name = ImageList[0].split('/').pop();
            for (let i = 0; i < veh.data.length; i++) {
                promise.push(collection.find({
                    $and: [{
                        $or: [{
                            metadata: veh.data[i].VIN
                        }]
                    },
                    {
                        $or: [{
                            filename: profile_name
                        }]
                    }
                    ]
                }))
            }

            Promise.all(promise)
                .then(docs => {
                    if (!docs || docs.length === 0) {
                        return res.render('index', {
                            title: 'Download Error',
                            message: 'No file found'
                        });
                    } else {
                        const promise = [];
                        for (let i = 0; i < docs.length; i++) {
                            promise.push(collectionChunks.find({
                                files_id: docs[i]._id
                            }))
                        }
                        Promise.all(promise)
                            .then(chunks => {
                                if (!chunks || chunks.length === 0) {
                                    return res.render('index', {
                                        title: 'Download Error',
                                        message: 'No data found'
                                    });
                                }

                                let fileData = []

                                for (let i = 0; i < chunks.length; i++) {
                                    fileData.push(chunks[i].data.toString('base64'));
                                }

                                let finalFile = 'data:' + docs[0].contentType + ';base64,' +
                                    fileData.join('');

                                if (finalFile) {
                                    var item = "testdatass"
                                    veh.data[i].FileData = item
                                }
                                console.log("Total Vehicle", vehicle.length)

                                return res.status(200).send({
                                    message: "success",
                                    pageNo: pageNo,
                                    totalRecords: veh.data.length,
                                    data: veh.data,
                                    totalPages: totalPages

                                })
                            })
                            .catch(error => {
                                return res.render('index', {
                                    title: 'Download Error',
                                    message: 'Error retrieving chunks',
                                    error: err.errmsg
                                });
                            })
                    }
                })
                .catch(error => {
                    return res.render('index', {
                        title: 'File error',
                        message: 'Error finding file',
                        error: error
                    });
                })
        })
    })
})

i tried to log console.log("docs[i]._id" . docs[i]._id) no results — Jhon Caylog, Nov 04 '19 at 06:49
Object assign problem is solved maybe database data issue there — Ankur Patel, Nov 04 '19 at 06:51
i console log the docs the result is this https://imgur.com/a/Cu1iGgO — Jhon Caylog, Nov 04 '19 at 06:53
at not the actual data result from thecollection.find query , also why did youremove that toArray? — Jhon Caylog, Nov 04 '19 at 06:57
there was a problem with this part for (let j = 0; j < docs.length; j++) { console.log("Datatata", docs[j]._id) the id is undefined although i have the docs data when i check — Jhon Caylog, Nov 04 '19 at 07:14
https://codeshare.io/5O4Bd0 , please visit the link sir i have posted the updated code the one i have fix — Jhon Caylog, Nov 04 '19 at 07:32
Let us [continue this discussion in chat](https://chat.stackoverflow.com/rooms/201818/discussion-between-jhon-caylog-and-ankur-patel). — Jhon Caylog, Nov 04 '19 at 07:48

Jayakumar Thangavel · Answer 2 · 2019-11-04T06:09:14.110

0

I suspect issue because of below

 for (let i = 0; i < docs.length; i++) {

inside also for loop variable names are same.

for (let i = 0; i < chunks.length; i++) {

edited Nov 04 '19 at 06:09

answered Nov 04 '19 at 05:49

Jayakumar Thangavel

1,884
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@JhonCaylog Please confirm – Jayakumar Thangavel Nov 04 '19 at 06:03
works fine on mine , the issue is on your side i think – Jhon Caylog Nov 04 '19 at 06:06
@JhonCaylog I mentioned outer for loop and inner for loop variable names are same. Try to change it. – Jayakumar Thangavel Nov 04 '19 at 06:13
but that is not the issue Sir – Jhon Caylog Nov 04 '19 at 06:14

NodeJS item was not added on the index of the object?

Full Code

Result

2 Answers2