Flutter – Navigating to home page after login button pressed not working

Issue

I new to flutter and cannot figure this one out.

My app is running with Flutter Web.

Registering page is successfully inserting user into MySQL DB, however, when I try login in (with correct data) it just keeps loading without navigating to the home page.

FYI – The backend is managed by PHP. This app is being debugged on Chrome browser.

Thanks in advance for your help.

The below code snippet is where navigating to home should be taking place within signin.dart

if (response.statusCode == 200) {
      Map<String, dynamic> resposne = jsonDecode(response.body);
      if (!resposne['error']) {
        Map<String, dynamic> user = resposne['data'];
        print(" User name ${user['id']}");
        savePref(1, user['name'], user['email'], user['id']);
        Navigator.pushReplacementNamed(context, "/home");
      } else {
        print(" ${resposne['message']}");
      }

Signin.dart

import 'dart:convert';
import 'dart:ui';

import 'package:flutter/material.dart';
import 'package:google_fonts/google_fonts.dart';
import 'package:rest_app/apis/api.dart';
import 'package:rest_app/screens/signup.dart';
import 'package:http/http.dart' as http;

import 'package:shared_preferences/shared_preferences.dart';
import 'home.dart';

class SignIn extends StatefulWidget {
  @override
  _SignInState createState() => _SignInState();
}

class _SignInState extends State<SignIn> {
  final _formKey = GlobalKey<FormState>();
  String email, password;
  bool isLoading = false;
  TextEditingController _emailController = new TextEditingController();
  TextEditingController _passwordController = new TextEditingController();
  GlobalKey<ScaffoldState> _scaffoldKey = GlobalKey();
  @override
  Widget build(BuildContext context) {
    return Scaffold(
        key: _scaffoldKey,
        body: SingleChildScrollView(
          child: Container(
            width: MediaQuery.of(context).size.width,
            height: MediaQuery.of(context).size.height,
            child: Stack(
              children: <Widget>[
                Container(
                  width: double.infinity,
                  height: double.infinity,
                  child: Image.asset(
                    "assets/background.jpg",
                    fit: BoxFit.fill,
                  ),
                ),
                Container(
                  child: Column(
                    crossAxisAlignment: CrossAxisAlignment.center,
                    mainAxisAlignment: MainAxisAlignment.center,
                    children: <Widget>[
                      Center(
                          child: Image.asset(
                        "assets/logo.png",
                        height: 30,
                        width: 30,
                        alignment: Alignment.center,
                      )),
                      SizedBox(
                        height: 13,
                      ),
                      Text(
                        "Learn With Us",
                        style: GoogleFonts.roboto(
                            textStyle: TextStyle(
                                fontSize: 27,
                                color: Colors.white,
                                letterSpacing: 1)),
                      ),
                      SizedBox(
                        height: 5,
                      ),
                      Container(
                        width: 180,
                        child: Text(
                          "RRTutors, Hyderabad",
                          textAlign: TextAlign.center,
                          style: GoogleFonts.roboto(
                            textStyle: TextStyle(
                                color: Colors.white54,
                                letterSpacing: 0.6,
                                fontSize: 11),
                          ),
                        ),
                      ),
                      SizedBox(
                        height: 40,
                      ),
                      Text(
                        "Sign In",
                        textAlign: TextAlign.center,
                        style: GoogleFonts.roboto(
                          textStyle: TextStyle(
                            color: Colors.white,
                            letterSpacing: 1,
                            fontSize: 23,
                          ),
                        ),
                      ),
                      SizedBox(
                        height: 8,
                      ),
                      Row(
                        mainAxisAlignment: MainAxisAlignment.center,
                        children: <Widget>[
                          Text(
                            "Learn new Technologies 😋",
                            textAlign: TextAlign.center,
                            style: GoogleFonts.roboto(
                              textStyle: TextStyle(
                                color: Colors.white70,
                                letterSpacing: 1,
                                fontSize: 17,
                              ),
                            ),
                          ),
                        ],
                      ),
                      SizedBox(
                        height: 30,
                      ),
                      Form(
                        key: _formKey,
                        child: Container(
                          margin: EdgeInsets.symmetric(
                              vertical: 10, horizontal: 45),
                          child: Column(
                            children: <Widget>[
                              TextFormField(
                                style: TextStyle(
                                  color: Colors.white,
                                ),
                                controller: _emailController,
                                decoration: InputDecoration(
                                  enabledBorder: UnderlineInputBorder(
                                      borderSide:
                                          BorderSide(color: Colors.white)),
                                  hintText: "Email",
                                  hintStyle: TextStyle(
                                      color: Colors.white70, fontSize: 15),
                                ),
                                onSaved: (val) {
                                  email = val;
                                },
                              ),
                              SizedBox(
                                height: 16,
                              ),
                              TextFormField(
                                style: TextStyle(
                                  color: Colors.white,
                                ),
                                controller: _passwordController,
                                decoration: InputDecoration(
                                  enabledBorder: UnderlineInputBorder(
                                      borderSide:
                                          BorderSide(color: Colors.white)),
                                  hintText: "Password",
                                  hintStyle: TextStyle(
                                      color: Colors.white70, fontSize: 15),
                                ),
                                onSaved: (val) {
                                  email = val;
                                },
                              ),
                              SizedBox(
                                height: 30,
                              ),
                              Stack(
                                children: [
                                  GestureDetector(
                                    onTap: () {
                                      if (isLoading) {
                                        return;
                                      }
                                      if (_emailController.text.isEmpty ||
                                          _passwordController.text.isEmpty) {
                                        _scaffoldKey.currentState.showSnackBar(
                                            SnackBar(
                                                content: Text(
                                                    "Please Fill all fileds")));
                                        return;
                                      }
                                      login(_emailController.text,
                                          _passwordController.text);
                                      setState(() {
                                        isLoading = true;
                                      });
                                      //Navigator.pushReplacementNamed(context, "/home");
                                    },
                                    child: Container(
                                      alignment: Alignment.center,
                                      width: double.infinity,
                                      padding: EdgeInsets.symmetric(
                                          vertical: 10, horizontal: 0),
                                      height: 50,
                                      decoration: BoxDecoration(
                                        border: Border.all(color: Colors.white),
                                        borderRadius: BorderRadius.circular(50),
                                      ),
                                      child: Text(
                                        "SUBMIT",
                                        textAlign: TextAlign.center,
                                        style: GoogleFonts.roboto(
                                            textStyle: TextStyle(
                                                color: Colors.white,
                                                fontSize: 16,
                                                letterSpacing: 1)),
                                      ),
                                    ),
                                  ),
                                  Positioned(
                                    child: (isLoading)
                                        ? Center(
                                            child: Container(
                                                height: 26,
                                                width: 26,
                                                child:
                                                    CircularProgressIndicator(
                                                  backgroundColor: Colors.green,
                                                )))
                                        : Container(),
                                    right: 30,
                                    bottom: 0,
                                    top: 0,
                                  )
                                ],
                              )
                            ],
                          ),
                        ),
                      ),
                      SizedBox(
                        height: 20,
                      ),
                      Text(
                        "OR",
                        style: TextStyle(fontSize: 14, color: Colors.white60),
                      ),
                      SizedBox(
                        height: 20,
                      ),
                      Image.asset(
                        "assets/fingerprint.png",
                        height: 36,
                        width: 36,
                      ),
                      SizedBox(
                        height: 30,
                      ),
                      GestureDetector(
                        onTap: () {
                          Navigator.pushReplacementNamed(context, "/signup");
                        },
                        child: Text(
                          "Don't have an account?",
                          style: GoogleFonts.roboto(
                              textStyle: TextStyle(
                                  color: Colors.white70,
                                  fontSize: 13,
                                  decoration: TextDecoration.underline,
                                  letterSpacing: 0.5)),
                        ),
                      )
                    ],
                  ),
                ),
              ],
            ),
          ),
        ));
  }

  login(email, password) async {
    Map data = {'email': email, 'password': password};
    print(data.toString());
    final response = await http.post(LOGIN,
        headers: {
          "Accept": "application/json",
          "Content-Type": "application/x-www-form-urlencoded"
        },
        body: data,
        encoding: Encoding.getByName("utf-8"));
    setState(() {
      isLoading = false;
    });
    if (response.statusCode == 200) {
      Map<String, dynamic> resposne = jsonDecode(response.body);
      if (!resposne['error']) {
        Map<String, dynamic> user = resposne['data'];
        print(" User name ${user['id']}");
        savePref(1, user['name'], user['email'], user['id']);
        Navigator.pushReplacementNamed(context, "/home");
      } else {
        print(" ${resposne['message']}");
      }
      _scaffoldKey.currentState
          .showSnackBar(SnackBar(content: Text("${resposne['message']}")));
    } else {
      _scaffoldKey.currentState
          .showSnackBar(SnackBar(content: Text("Please try again!")));
    }
  }

  savePref(int value, String name, String email, int id) async {
    SharedPreferences preferences = await SharedPreferences.getInstance();

    preferences.setInt("value", value);
    preferences.setString("name", name);
    preferences.setString("email", email);
    preferences.setString("id", id.toString());
    preferences.commit();
  }
}

Log

Running with unsound null safety
For more information see https://dart.dev/null-safety/unsound-null-safety
Debug service listening on ws://127.0.0.1:60476/FtYO7LqYdYw=/ws
{email: test@gmail.com, password: password}
Error: XMLHttpRequest error.
    dart-sdk/lib/_internal/js_dev_runtime/patch/core_patch.dart 906:28                get current
packages/http/src/browser_client.dart 84:22                                       <fn>
dart-sdk/lib/async/zone.dart 1612:54                                              runUnary
dart-sdk/lib/async/future_impl.dart 152:18                                        handleValue
dart-sdk/lib/async/future_impl.dart 704:44                                        handleValueCallback
dart-sdk/lib/async/future_impl.dart 733:13                                        _propagateToListeners
dart-sdk/lib/async/future_impl.dart 530:7                                         [_complete]
dart-sdk/lib/async/stream_pipe.dart 61:11                                         _cancelAndValue
dart-sdk/lib/async/stream.dart 1219:7                                             <fn>
dart-sdk/lib/_internal/js_dev_runtime/private/ddc_runtime/operations.dart 324:14  _checkAndCall
dart-sdk/lib/_internal/js_dev_runtime/private/ddc_runtime/operations.dart 329:39  dcall
dart-sdk/lib/html/dart2js/html_dart2js.dart 37307:58                              <fn>


    at Object.createErrorWithStack (http://localhost:60442/dart_sdk.js:5348:12)
    at Object._rethrow (http://localhost:60442/dart_sdk.js:39350:16)
    at async._AsyncCallbackEntry.new.callback (http://localhost:60442/dart_sdk.js:39344:13)
    at Object._microtaskLoop (http://localhost:60442/dart_sdk.js:39176:13)
    at _startMicrotaskLoop (http://localhost:60442/dart_sdk.js:39182:13)
    at http://localhost:60442/dart_sdk.js:34689:9

Solution

This significant line in the error is this one:

Error: XMLHttpRequest error.

This means a HTTP request failed, which is throwing an exception before the navigation code is even executed.

Debugging on a platform other than Web is recommended, as you can use stateful hot reload and get line numbers in your traces, which would have made this issue clearer.

Answered By – hacker1024

Answer Checked By – Senaida (FlutterFixes Volunteer)

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