How to delete a field in Firestore document with flutter - dart

Question

I'm making a Flutter application.
But, I cannot delete a field in the Firestore document.
In another language I know to use FieldValue.delete() to delete a file in Firestorm document.
In Dart, How do I delete?

Answer 1

Update Oct,2018: This is Now Possible:
In order to delete a particular field from a Cloud Firestore document - make sure you are using Plugin version 0.8.0 or Above. Now a E.g If you have a document having a field 'Desc' with contain some Text. In Order to Delete it.
Firestore.instance.collection('path').document('name').update({'Desc': FieldValue.delete()}).whenComplete((){
print('Field Deleted');
});
This will Delete 'Desc' Field from the Document 'name'

Answer 2

I think this is currently impossible in standard, non hacky way.
There is an open issue https://github.com/flutter/flutter/issues/13905 in Flutter which have to be resolved first.

Answer 3

Get the DocumentReference, invoke update with a map which has a key you want to delete and value FieldValue.delete().
var collection = FirebaseFirestore.instance.collection('collection');
collection
.doc('document_id')
.update({
'field_to_delete': FieldValue.delete(),
}
);

Answer 4

Here is an official solution for deleting Field Path when programming in Flutter/Dart
Here is how a sample Firestore collection looks like:
{
'path': {
'name': {
'title': 'my title'
'description': 'my description',
}
}
}
In order to delete description field, you can do this:
Firestore.instance.collection('path').document('name').set(
{'description': FieldValue.delete()},
SetOptions(
merge: true,
),
)
And the collection will look like this:
{
'path': {
'name': {
'title': 'my title'
}
}
}

Answer 5

if you have nested fields then use the '.' (Dot) notation to specify the field.
E.g if your data is nested Map then this is handy.
Firestore.instance.collection('path').document('name').update({'address.town': FieldValue.delete()}).whenComplete((){
print('Field Deleted');
});