Express return value from method with callback

Question

Why does this

router.get('/eventTest/:id', function (req, res) {

var event = Event.getEventById(req.params.id, function (err, rows) {
    if(err) {
        return err;
    } else {
        return rows;
    }
});

res.json(event);

});

returns { "domain": null, "_events": {}, "_eventsCount": 0, "_callSite": {}, "_ended": false, "_idleNext": null, "_idlePrev": null, "_idleStart": null, "_idleTimeout": -1, "_repeat": null, "sql": "select * from event where id=?", "values": [ "1" ], "typeCast": true, "nestTables": false, "_resultSet": null, "_results": [], "_fields": [], "_index": 0, "_loadError": null }

this and example of one of the methods that I'm calling

`getEventById:function(id,callback){

    return db.query("select * from event where id=?",[id],callback);
}

`

rather than the actual values like it does when I use res.json(rows) inside the Event.getEventById callback?

I need this in order to call multiple methods and add them to an object and then send that object in JSON

Thank you

abdulbari · Accepted Answer · 2017-04-11 12:18:20Z

3

As per your code, yes you need to send response from method.

Since as Node.js nature is async so you need to write your code in that way

Try it in your route

Event.getEventById(req.params.id, function (err, rows) {
    if(err) {
        res.status(500).send(err);
    } else {
      res.status(200).send(rows);
    }
});

UPDATE

To execute multiple methods and send all records at single time then go through

async module or promise

edited Apr 11, 2017 at 12:18

answered Apr 11, 2017 at 11:59

abdulbari

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7 Comments

Nuno Bettencourt Over a year ago

It works, but my idea was to call multiple methods and assign the result to an object and then res.send that object. For example:

var event = {};  event.details = Event.getEventById(req.params.id, function (err, rows) {         if(err) {             return err;         } else {             return rows;         }     });  event.teams =Event.getEventStages(req.params.id, function (err, rows) {         if(err) {             return err;         } else {             return rows;         }     });  res.json(event);

abdulbari Over a year ago

Yes, you can use promise or async module

abdulbari Over a year ago

Use async.waterfall or series to get your desire result

Nuno Bettencourt Over a year ago

I tried express-promise and it still returned the query and not the results

abdulbari Over a year ago

Use promise.all, write all your methods als at last call all, take the sample from link. Hope that will work!!

|

Nuno Bettencourt · Accepted Answer · 2017-04-11 13:16:33Z

1

I tried "express-promise" like this:

`router.get('/eventTest/:id', function (req, res) {
    res.json({
       details: Event.getEventById(req.params.id),
       stages: Event.getEventStages(req.params.id)
    });
 });`

and still got the same result (i.e. the query and not the values). I'm guessing that my problem is the way that I managing the callbacks from the methods. Is this right?

answered Apr 11, 2017 at 13:16

Nuno Bettencourt

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Comments

Aikon Mogwai · Accepted Answer · 2017-04-11 11:58:20Z

0

router.get('/eventTest/:id', function (req, res, next) {

  Event.getEventById(req.params.id, function (err, rows) {
    if(err) 
        return next(err);

    res.json(rows);
  });
});

answered Apr 11, 2017 at 11:58

Aikon Mogwai

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