Advance Mobile application devep -(firebase part 02) for applied scince college stuents seiyun University , yemen class - 05

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();
}