How to start something automatically in flutter - flutter

Question

I have the following code that initially displays a blank page, but I'd like an rAlert dialog to display automatically. Once the user clicks 'Request' or 'Cancel', some text will be displayed on the screen.
But I can't get the code to run that displays the Alert. I had it working by showing a button and clicking the button, but i need the Alert to display automatically when the page is displayed. I tried putting it in the initState. I didn't get any errors, but it didn't work either.
Anyone know what I need to do? Thanks?
import 'package:flutter/material.dart';
import 'package:rflutter_alert/rflutter_alert.dart';
import 'dart:async';
import 'package:rostermeon/cwidgets/general_widgets.dart';
import 'package:rostermeon/rmo_constants.dart';
class ForgotPassword extends StatefulWidget {
static const String id = 'forgot_password_screen';
#override
_ForgotPasswordState createState() => _ForgotPasswordState();
}
class _ForgotPasswordState extends State<ForgotPassword> {
StreamController<bool> _events;
#override
initState() {
super.initState();
_events = new StreamController<bool>();
doRequest(context: context);
}
Future<bool> doSaveRequest({String pReason}) async {
await Future.delayed(const Duration(seconds: 3), () {});
return false;
}
Future<bool> doRequest({context}) {
String _reason = '';
GlobalKey<FormState> _formKey = GlobalKey<FormState>();
TextEditingController reasonController = TextEditingController();
TextStyle _style = TextStyle(fontFamily: 'Montserrat', fontSize: 18.0, fontWeight: FontWeight.normal);
InputDecoration _textFormFieldDecoration({String hintText, double padding}) => InputDecoration(
//contentPadding: EdgeInsets.fromLTRB(8.0, 8.0, 8.0, 8.0),
contentPadding: EdgeInsets.all(padding),
isDense: true,
hintText: hintText,
hintStyle: TextStyle(color: kHintText),
border: OutlineInputBorder(
borderRadius: BorderRadius.all(Radius.circular(5)),
),
);
return Alert(
context: context,
title: 'Request New Password',
content: StreamBuilder<bool>(
initialData: false,
stream: _events.stream,
builder: (BuildContext context, AsyncSnapshot<bool> snapshot) {
print(" ${snapshot.data.toString()}");
return snapshot.data
? CircularProgressIndicator()
: Form(
key: _formKey,
child: Column(
crossAxisAlignment: CrossAxisAlignment.start,
children: <Widget>[
SizedBox(height: 20.0),
Text('Email', textAlign: TextAlign.left, style: _style),
SizedBox(height: 10.0),
TextFormField(
validator: (value) {
if (value.isEmpty) {
return "please enter email";
}
return null;
},
onSaved: (value) {
_reason = value;
},
decoration: _textFormFieldDecoration(
hintText: 'your email address',
padding: 8.0,
),
controller: reasonController,
),
SizedBox(height: 10.0),
],
),
);
}),
buttons: [
DialogButton(
child: Text('Request', style: TextStyle(color: Colors.white, fontSize: 20)),
color: kMainColor,
onPressed: () async {
if (_formKey.currentState.validate()) {
_formKey.currentState.save();
print(_reason);
_events.add(true);
var saved = await doSaveRequest(pReason: _reason);
if (saved) {
Navigator.pop(context, false);
} else {
_events.add(false);
}
Navigator.of(context).pop();
// Navigator.pop(context, false);
}
},
),
DialogButton(
child: Text('Cancel', style: TextStyle(color: Colors.white, fontSize: 20)),
color: kMainColor,
onPressed: () {
Navigator.pop(context, false);
},
),
],
).show();
}
#override
Widget build(BuildContext context) {
return Scaffold(
appBar: rmoAppBar(subText: 'Request New Password', hideBackButton: false),
body: Center(
child: Column(
mainAxisAlignment: MainAxisAlignment.center,
children: <Widget>[],
),
),
);
}
}

Answer 1

Dialogs/Alerts need the buildContext in order to work, You can't have the buildContext before build() method is called, that's why you can't just call it in initstate() before the build is called.
To make it work use addPostFrameCallback to make sure it delays until widget is built:
void initState() {
super.initState();
WidgetsBinding.instance
.addPostFrameCallback((_) => yourMethod(context));
}
https://www.didierboelens.com/2019/04/addpostframecallback/