add file base local storage

lib/home.dart

@@ -1,6 +1,7 @@
 import 'package:flutter/material.dart';
 import 'package:flutter/widgets.dart';
 import 'package:flutter_complete_guide/main.dart';
+import 'package:flutter_complete_guide/transactions_repo.dart';
 import 'package:flutter_complete_guide/widgets/custom_appbar.dart';
 import 'package:flutter_complete_guide/widgets/header_wallet.dart';
 import 'package:flutter_complete_guide/widgets/new_transaction.dart';
@@ -9,12 +10,15 @@ import 'package:flutter_complete_guide/widgets/transaction_record.dart';
 import 'models/transaction.dart';
 
 class MyHomePage extends StatefulWidget {
+  final TransactionsRepo repo;
+  MyHomePage({this.repo});
+
   @override
   _MyHomePageState createState() => _MyHomePageState();
 }
 
 class _MyHomePageState extends State<MyHomePage> {
-  final List<Transaction> _userTransactions = [];
+  List<Transaction> _userTransactions = [];
 
   void _addNewTransaction(
     String txTitle,
@@ -31,6 +35,8 @@ class _MyHomePageState extends State<MyHomePage> {
     setState(() {
       _userTransactions.add(newTx);
     });
+
+    widget.repo.saveTransactions(_userTransactions);
   }
 
   void _startAddNewTransaction(BuildContext ctx) {
@@ -49,6 +55,7 @@ class _MyHomePageState extends State<MyHomePage> {
   void _deleteTransaction(String id) {
     setState(() {
       _userTransactions.removeWhere((tx) => tx.id == id);
+      widget.repo.saveTransactions(_userTransactions);
     });
   }
 
@@ -60,6 +67,17 @@ class _MyHomePageState extends State<MyHomePage> {
     return balance;
   }
 
+  @override
+  void initState() {
+    super.initState();
+    widget.repo.loadTransactions().then((value) {
+        setState(() {
+          _userTransactions.clear();
+          _userTransactions.addAll(value);
+        });
+    });
+  }
+
   @override
   Widget build(BuildContext context) {
     return Scaffold(

lib/main.dart

@@ -1,4 +1,5 @@
 import 'package:flutter/material.dart';
+import 'package:flutter_complete_guide/transactions_repo.dart';
 
 import 'home.dart';
 
@@ -14,7 +15,7 @@ class MyApp extends StatelessWidget {
         fontFamily: 'Sanomat',
         textTheme: ThemeData.light().textTheme,
       ),
-      home: MyHomePage(),
+      home: MyHomePage(repo: SharedPrefTransactionsRepo()),
     );
   }
 }

lib/models/transaction.dart

@@ -15,4 +15,20 @@ class Transaction {
     String label,
     this.isIncoming = false,
   });
+
+
+  factory Transaction.fromJson(Map<String, dynamic> json) => Transaction(
+      id: json['id'],
+      title: json['title'],
+      amount: json['amount'],
+      date: DateTime.now());
+
+  Map<String, dynamic> toJson() => {
+    "id" : id,
+    "title": title,
+    "amount": amount,
+    "date": date.toString(),
+    "label" : "",
+    "isIncoming": false
+  };
 }

lib/transactions_repo.dart

@@ -0,0 +1,49 @@
+
+import 'dart:convert';
+import 'dart:io';
+
+import 'package:path_provider/path_provider.dart';
+
+import 'models/transaction.dart';
+
+abstract class TransactionsRepo {
+  Future<List<Transaction>> loadTransactions();
+  void saveTransactions(List<Transaction> trans);
+}
+
+class SharedPrefTransactionsRepo extends TransactionsRepo {
+
+  Future<String> get _localPath async {
+    final directory = await getApplicationDocumentsDirectory();
+    return directory.path;
+  }
+
+  Future<File> get _localFile async {
+    final path = await _localPath;
+    return File("$path/transactions.json");
+  }
+
+  @override
+  Future<List<Transaction>> loadTransactions() async {
+    try {
+      final file = await _localFile;
+      final String content = await file.readAsString();
+      final decode = json.decode(content);
+
+      final List<Transaction> trans = [];
+      decode.forEach((element) {
+        trans.add(Transaction.fromJson(element));
+      });
+
+      return trans;
+    } catch (e) {
+      return List.empty();
+    }
+  }
+
+  @override
+  void saveTransactions(List<Transaction> trans) async {
+      final file = await  _localFile;
+      file.writeAsString(jsonEncode(trans));
+  }
+}

pubspec.yaml

@@ -20,11 +20,9 @@ dependencies:
   flutter:
     sdk: flutter
   intl: ^0.15.8
-
-  # The following adds the Cupertino Icons font to your application.
-  # Use with the CupertinoIcons class for iOS style icons.
   cupertino_icons: ^0.1.2
   flutter_svg: ^0.18.1
+  path_provider: ^1.5.1
 
 dev_dependencies:
   flutter_test: