Flutter: How can use FieldValue.arrayRemove?

Question

How can I delete an array of array of objects from Firestore? I want to delete it inside a list.generate

Here is my database structure, I want to delete [{street A, number 25}]

enter image description here

List.generate(
  ...
  IconButton(
    icon: const Icon(CupertinoIcons.trash),
    onPressed: () async {
      try {
        await FirebaseFirestore.instance
            .collection('users')
            .doc(data['uid'])
            .update(
          {
            'adress':
                FieldValue.arrayRemove(
                    ??)
          },
        );
      } catch (e) {
        print(e);
      }
    },
  ),
)),

Please edit your question and add your database structure as a screenshot and indicate the exact data you want to delete. — Alex Mamo
– Alex Mamo, Commented Feb 8, 2022 at 11:58

Alex Mamo · Accepted Answer · 2022-02-08 14:20:37Z

3

As I see in your screenshot, the adress field is not of type array, it's a Map:

So there is no way you can call FieldValue.arrayRemove. If you want to remove that field, then please use the following lines of code:

Firestore.instance.collection('users').document(data['uid']).set(
    {'adress': FieldValue.delete()},
    SetOptions(
      merge: true,
    ),
)

Edit:

After you have updated the screenshot, now the adress field is indeed of type array:

If you want to delete a specific object from the array using FieldValue.delete(), you should use all the data in the object and not partial data. I have even written an article regarding updating an array of objects in Cloud Firestore:

How to update an array of objects in Firestore?

Edit2:

In code it should look like this:

Firestore.instance.collection('users').document(data['uid']).update({
    'adress': FieldValue.arrayRemove(elementToDelete),
});

Please note that elementToDelete object should contain both fields populated. The number should hold the value of "25" and street should hold the value of "street A". It will not work if you use only one.

However, if you thought that Firestore provides a direct way to delete an array element by index, please note that is not possible. In such a case, you'll have to read the document, remove the element from the array, then write the document back to Firestore.

edited Feb 8, 2022 at 14:20

answered Feb 8, 2022 at 12:26

Alex Mamo

139k18 gold badges171 silver badges202 bronze badges

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

6 Comments

Mus Over a year ago

but what I do If a have more adresses and I want to delete just one?

Alex Mamo Over a year ago

There is no way you can add multiple addresses under the adress field. Since it's a Map, it doesn't allow duplicate keys. So only one address can be stored. If you want to add multiple addresses then you should change the type of the property from Map to array.

Mus Over a year ago

Ups! I update the photo to show exacthy what I want, sorry for the mistake

Alex Mamo Over a year ago

In that case, please check my updated answer.

Mus Over a year ago

I can't follow your tutorial, I'm new with flutter and I I am not able to fully understand it. Can u please wrote a simple solution for me?

|

Collectives™ on Stack Overflow

Flutter: How can use FieldValue.arrayRemove?

1 Answer 1

6 Comments

Your Answer

Linked

Hot Network Questions

Collectives™ on Stack Overflow

1 Answer 1

6 Comments

Your Answer

Sign up or log in

Post as a guest

Linked

Related