doc method
Returns a DocumentReference
with the provided path.
If no path
is provided, an auto-generated ID is used.
The unique key generated is prefixed with a client-generated timestamp so that the resulting list will be chronologically-sorted.
Implementation
DocumentReference doc([String? path]) {
if (path != null) {
assert(path.isNotEmpty, 'a document path must be a non-empty string');
assert(!path.contains('//'), 'a document path must not contain "//"');
assert(path != '/', 'a document path must point to a valid document');
}
return DocumentReference._(firestore, _delegate.doc(path));
}