Improve credentials form. Added shared_preferences.

lib/ui/credentials_form.dart

@@ -1,18 +1,24 @@
 import 'package:flutter/material.dart';
+import 'package:logger/logger.dart';
+import 'package:shared_preferences/shared_preferences.dart';
 
+final log = Logger();
 
 class CredentialsForm extends StatefulWidget {
-  CredentialsForm({Key key}) : super(key: key);
+  CredentialsForm({@required this.defaultNextRoute, Key key}) : super(key: key);
+  final String defaultNextRoute;
 
   @override
   _CredentialsState createState() => _CredentialsState();
 }
 
 class _CredentialsState extends State<CredentialsForm> {
+  static String title = "Credentials";
   String username;
   String password;
   bool _hidden = true;
   final _credFormKey = GlobalKey<FormState>();
+  final _scaffoldKey = GlobalKey<ScaffoldState>();
   InputDecoration _textFieldDecoration(String label, IconData icon) {
     return InputDecoration(
       labelText: label,
@@ -35,9 +41,37 @@ class _CredentialsState extends State<CredentialsForm> {
     return null;
   }
 
-  @override
-  Widget build(BuildContext context) {
-    return Form(
+  Future<String> getNextRoute() async {
+    var persistence = await SharedPreferences.getInstance();
+    String nextRoute = persistence.getString("nextRoute");
+    if (nextRoute != null) {
+      log.d("nextRoute: $nextRoute");
+      return nextRoute;
+    }
+    log.d("defaultNextRoute: ${widget.defaultNextRoute}");
+    return null;
+  }
+
+  Future<void> _onPressed() async {
+    var persistence = await SharedPreferences.getInstance();
+    if (_credFormKey.currentState.validate()) {
+      _scaffoldKey.currentState
+          .showSnackBar(SnackBar(content: Text('Processing Data')));
+    }
+    _credFormKey.currentState.save();
+    log.d("username: ${this.username}\tpassword: ${this.password}");
+    persistence.setString("username", this.username);
+    persistence.setString("password", this.password);
+    String nextRoute = await getNextRoute();
+    if (nextRoute == null) {
+      Navigator.pushNamedAndRemoveUntil(
+          context, widget.defaultNextRoute, (Route<dynamic> route) => false);
+    } else {
+      Navigator.pushNamed(context, nextRoute);
+    }
+  }
+
+  Form theForm() => Form(
       key: _credFormKey,
       child: Column(children: <Widget>[
         TextFormField(
@@ -45,22 +79,23 @@ class _CredentialsState extends State<CredentialsForm> {
             autocorrect: false,
             decoration:
                 this._textFieldDecoration("username", Icons.alternate_email),
-              validator: this.validateUsername),
+            validator: this.validateUsername,
+            onSaved: (String user) {
+              username = user;
+            }),
         TextFormField(
             autocorrect: false,
             decoration: this._textFieldDecoration("password", Icons.lock),
             validator: this.validatePassword,
-              obscureText: this._hidden),
+            obscureText: this._hidden,
+            onSaved: (String pass) {
+              password = pass;
+            }),
         Row(
             mainAxisAlignment: MainAxisAlignment.spaceBetween,
             children: <Widget>[
               RaisedButton(
-              onPressed: () {
-                if (_credFormKey.currentState.validate()) {
-                  Scaffold.of(context)
-                      .showSnackBar(SnackBar(content: Text('Processing Data')));
-                }
-              },
+                onPressed: this._onPressed,
                 child: Text('Validate'),
               ),
               Row(children: <Widget>[
@@ -76,5 +111,10 @@ class _CredentialsState extends State<CredentialsForm> {
               ])
             ]),
       ]));
+
+  @override
+  Widget build(BuildContext context) {
+    return Scaffold(
+        key: _scaffoldKey, appBar: AppBar(title: Text(title)), body: theForm());
   }
 }

pubspec.lock

@@ -109,6 +109,13 @@ packages:
       url: "https://pub.dartlang.org"
     source: hosted
     version: "2.0.3"
+  shared_preferences:
+    dependency: "direct main"
+    description:
+      name: shared_preferences
+      url: "https://pub.dartlang.org"
+    source: hosted
+    version: "0.5.3+4"
   sky_engine:
     dependency: transitive
     description: flutter
@@ -172,3 +179,4 @@ packages:
     version: "2.0.8"
 sdks:
   dart: ">=2.2.2 <3.0.0"
+  flutter: ">=1.5.0 <2.0.0"

pubspec.yaml

@@ -23,6 +23,7 @@ dependencies:
   http: ^0.12.0+2
   logger: ^0.7.0+2
   dbcrypt: ^1.0.0
+  shared_preferences: ^0.5.3+4
   # The following adds the Cupertino Icons font to your application.
   # Use with the CupertinoIcons class for iOS style icons.
   cupertino_icons: ^0.1.2