The document covers advanced mobile application development using Firebase, focusing on data management methods such as addition, retrieval, updating, and deletion of data through Firestore in a Flutter environment. It elaborates on the use of streams and StreamBuilder for real-time updates to the UI, emphasizing lifecycle methods such as initState for data initialization. Additionally, it provides example code snippets for various functionalities, showcasing the integration of Firebase Firestore with Flutter widgets.

1. Advance Mobile Application
Development
Firebase part 2
Dr. Mazin Alkathiri
IT Department
Seiyun University
2023-2024

2. Future addAnyData(Map<String, dynamic> ListMap, String id, String CollectionName)async{
return await FirebaseFirestore.instance
.collection(CollectionName)
.doc(id)
.set(ListMap);
}
Future addData(Map<String, dynamic> DoctorsInfoMap, String id)async{
return await FirebaseFirestore.instance
.collection("lecturer")
.doc(id)
.set(LecInfoMap);
}

3. Firestore
• Used to
• Store data
• Add data
• Modify data
• Delete data
• Firestore Store data as Documents and each Document inside a
collection

4. Reading data from Firestore collection as stream
• In the class Databasemethods which we have created earlier we can
add a new function to read the whole data of a collection.
Future<Stream<QuerySnapshot>> getData(String CollectionName) async{
return await FirebaseFirestore.instance.collection(CollectionName).snapshots();
}
uture<Stream<QuerySnapshot>> getData(String CollectionName) async{
return await fdb
.collection(CollectionName)
.snapshots();
}
FirebaseFirestore fdb = FirebaseFirestore.instance;

5. Stream? LecturerStream;
getontheload() async{
LecturerStream=await Databasemethods().getData("lecturer");
setState(() {
});
}
@override
void initState() {
getontheload();
super.initState();
}

6. Uses of initState():
• initState() is a method of class State and it is considered as an
important lifecycle method in Flutter. initState() is called the only
once and we use it for one-time initializations.
• Example :
• To initialize data that depends on the specific BuildContext.
• To initialize data that need to execute before build()
• Subscribe to Streams.
• initState() is called once and only once. It must also
call super.initState()

7. Building the vessel for the data
Widget allLecDetails(){
return StreamBuilder(
>>> Stream builder settings <<<
? ListView.builder(
>>>ListView setting<<<
return Material(
>>> the card or material elements<<<
);
}):Container();
});
}
>>> Stream builder settings <<<
return StreamBuilder(
stream: LecturerStream,
builder:(context, AsyncSnapshot snapshot){
return snapshot.hasData
? ListView.builder(
>>>ListView setting<<<
? ListView.builder(
itemCount: snapshot.data.docs.length,
itemBuilder: (context, index){
DocumentSnapshot ds=snapshot.data.docs[index];
return Material(

8. StreamBuilder
• A StreamBuilder in Flutter is used to listen to a stream of data
and rebuild its widget subtree whenever new data is emitted by the
stream. It’s commonly used for real-time updates, such as when
working with streams of data from network requests, databases, or
other asynchronous sources.

9. return Material(
elevation: 5.0,
borderRadius: BorderRadius.circular(10),
child: Container(
padding: EdgeInsets.all(20),
width: MediaQuery.of(context).size.width,
decoration: BoxDecoration(color: Colors.white,borderRadius: BorderRadius.circular(10)),
child: Column(
crossAxisAlignment: CrossAxisAlignment.start,
children: [
Text("name : "+ds["lecName"],
style:TextStyle(color: Colors.blue,fontSize: 20.0, fontWeight: FontWeight.bold) ),
Text("college : "+ds["lecCol"],
style:TextStyle(color: Colors.blue,fontSize: 20.0, fontWeight: FontWeight.bold) ),
Text("Department : "+ds["lecDept"],
style:TextStyle(color: Colors.blue,fontSize: 20.0, fontWeight: FontWeight.bold) ),
Text("Phone No. : "+ds["lecPhNo"],
style:TextStyle(color: Colors.blue,fontSize: 20.0, fontWeight: FontWeight.bold) ),
],
),
),
);

10. @override
Widget build(BuildContext context) {
return Scaffold(
appBar: AppBar(
backgroundColor: Theme.of(context).colorScheme.inversePrimary,
title: Text(“Lecturers of Seiyun University"),
),
body: Padding(
padding: const EdgeInsets.all(16.0),
child: Column(
children: [
Expanded(child: allLecDetails()),
]
)
)
);
}

11. Read and show some specific data in a stream
Future<Stream<QuerySnapshot>> getselectedData
(String CollectionName,String docname,String docvalue) async{
return await FirebaseFirestore.instance
.collection(CollectionName)
.where(docname, isEqualTo: docvalue)
.snapshots();
}

12. child: Column(
children: [
TextField(
controller: collectionname,
),
TextField(
controller: docname,
),
TextField(
controller: docvalue,
),
ElevatedButton(
child: Text(
"‫"بحث‬,
style: TextStyle(
fontSize: 16.0,
),
),
),
]
)
onPressed: () async{
LecturerStream=await Databasemethods()
.getselectedData(collectionname.text,docname.text,docvalue.text)
.then((value) {
Navigator.push(
context,
MaterialPageRoute(
builder: (context) => Showdata(LecturerStream: value),
),
);
});
}

13. Updating data
Future updateData
(Map<String, dynamic> ListMap, String id, String CollectionName)async{
return await FirebaseFirestore.instance
.collection(CollectionName)
.doc(id)
.update(ListMap);
}

14. Future deleteData
(String id, String CollectionName)async{
return await FirebaseFirestore.instance
.collection(CollectionName)
.doc(id)
.delete();
}