Error at Converting A Firebase Database Snapshot To An Array In TypeScript

Question

I've been following this tutorial https://ilikekillnerds.com/2017/05/convert-firebase-database-snapshotcollection-array-javascript/ in order to convert a firebase snapshot into an array in my ionic application. This is the code I have:

https://github.com/dladinot/AplicativoTutoriasMoviles/blob/master/src/pages/buscar-tutor/buscar-tutor.ts

And this is my data structure in firebase:

When I use my code this is the error it gives me:

And when I debbug that line of code where the error seems to be, I can see that the first item in the snapshot is stored in the array, then the next value is undefined. Although if I just print the keys it prints just fine:

Anyone has any idea what's going on?

you have several boolean properties in your database like boolLogin and disponible. hence when you are using foreach to iterate the values and add a key to them you are getting this error because it's trying to add key to the item even when it has boolean value in this line item.key=childSnapshot.key; — Niladri
– Niladri, Commented Oct 21, 2017 at 17:09
But even if I delete the boolean fields and leave only the string ones, it gives me the same problem. I will update the question with the output in no boolean fields — Daniel Esteban Ladino Torres
– Daniel Esteban Ladino Torres, Commented Oct 21, 2017 at 17:18

Niladri · Accepted Answer · 2017-10-21 17:19:39Z

1

you have several boolean properties in your database like boolLogin and disponible. hence when you are using foreach to iterate the values and add a key to them you are getting this error because it's trying to add key to the item even when it has boolean value in this line

item.key=childSnapshot.key;

try to add the snapshots to the array using the below code

this.consultaTutor=this.afDatabase.object(`profile/SlHGkc3ZK0hHxH2s1sowpgGuJfA3`, {preserveSnapshot: true})
          this.consultaTutor.subscribe(info=>{
            info.forEach(childSnapshot=>{  
              var value = childSnapshot.val();
              var key = childSnapshot.key;
              console.log(childSnapshot.key);
              var item = { "key" : key, "value" : value};
              this.listaTutores.push(item);      
            })

answered Oct 21, 2017 at 17:19

Niladri

5,9922 gold badges27 silver badges45 bronze badges

Sign up to request clarification or add additional context in comments.

Collectives™ on Stack Overflow

Error at Converting A Firebase Database Snapshot To An Array In TypeScript

1 Answer 1

Comments

Your Answer

Hot Network Questions

Collectives™ on Stack Overflow

1 Answer 1

Comments

Your Answer

Sign up or log in

Post as a guest

Related