How to toLowerCase() on data from Flutter Firestore? - firebase

Question

I made an application and coded a search system between documents in the application. But there is a problem:
The incoming record is registered as "Durmuş Bolat" in Firestore. And as you can see, the letter D of Durmuş is capitalized. That's why I have to capitalize the first letter in the search. And that's a problem.
I want to get the result of "Durmuş Bolat" even if I write it in the following ways:
durmuş bolat
DURMUŞ BOLAT
DuRmUs BoLaT
As a solution to this, I thought of shrinking the searched content and all the incoming content. So all incoming data and searched content will be downsized with toLowerCase.
I don't have the slightest idea where to place this toLowerCase code. Can you help me?
Codes:
var _searchText;
return Scaffold(
appBar: AppBar(
title: Container(
height: 50,
width: 250,
child: TextFormField(
autofocus: true,
style: TextStyle(color: Colors.white),
onChanged: (value) {
setState(() {
_searchText = value;
});
},
),
),
),
body: Column(
children: [
Container(
height: MediaQuery.of(context).size.height * 0.8, //MediaQuery.of(context).size.height * 0.8,
child: StreamBuilder<QuerySnapshot<Map<String, dynamic>>>(
stream: FirebaseFirestore.instance.collection('bolatTamir').where('nameSurname', isGreaterThanOrEqualTo: _searchText).snapshots(),
builder: (context, snapshot) {
if (!snapshot.hasData) {
return Center(
child: CircularProgressIndicator(),
);
}
return ListView.builder(
itemCount: snapshot.data!.docs.length,
itemBuilder: (context, index) {
return InkWell(
child: ListTile(
leading: CircleAvatar(
backgroundImage: NetworkImage(snapshot.data!.docs[index].data()['urunFotografi']),
),
title: Text(snapshot.data!.docs[index].data()['nameSurname'], style: TextStyle(fontSize: 20),),
subtitle: Text(snapshot.data!.docs[index].data()['yapildiMi'] == false ? 'Tamamlanmadı' : 'Tamamlandı', style: TextStyle(fontSize: 17),),
trailing: Text(snapshot.data!.docs[index].data()['tamirUcreti'], style: TextStyle(fontSize: 20),),
),
);
},
);
},
),
),
],
),
);
Thank you in advance for your help.

Answer 1

To my knowledge, lower-casing text that is already stored is not possible with Firebase. One can only lower-case the search term.
If it is just names and not tons of text, one could
.split(' ') these names, then
.toLowerCase() all resulting words, then
store them in a search-index-collection.
Then, search this search-index-collection and resolve the $userId.
.
users/34td24y3gtdb724/
{
name: 'Durmuş Bolat'
}
searchindex/
{
word: 'durmuş',
userId: 34td24y3gtdb724
word: 'bolat',
userId: 34td24y3gtdb724
}
Google itself asks to use Third-Party-Providers for full text search:
https://cloud.google.com/firestore/docs/solutions/search
Also, there is an approach to generate permutations as an Array:
https://medium.com/flobiz-blog/full-text-search-with-firestore-on-android-622af6ca5410