[Question] How to update specific widget in widget tree ?

[aniketsongara]

Here I don't want to update Html(data: provider.getHtmlContents) widget in the widget tree, how can I achieve this.
I have to keep Consumer() at top of the widget tree and I don't want to rebuild some of widget in the Consumer().
I have the same scenario in my project and I am struggling to stop rebuilding the widget. please help me out.

import 'package:flutter/material.dart';
import 'package:flutter_html/flutter_html.dart';
import 'package:provider/provider.dart';
void main() {
  runApp(MaterialApp(
    home: ChangeNotifierProvider<PositionProvider>(
      create: (context) => PositionProvider(),
      child: Test(),
    ),
  ));
}

class Test extends StatefulWidget {
  @override
  State<StatefulWidget> createState() {
    return _TestState();
  }
}

class _TestState extends State<Test> {
  @override
  Widget build(BuildContext context) {
    PositionProvider provider = Provider.of<PositionProvider>(context,listen: false);
    return Scaffold(
      appBar: AppBar(
        title: Text("Test Provider"),
      ),
      body: Column(
        children: [
          Row(
            mainAxisAlignment: MainAxisAlignment.spaceAround,
            children: [
              TextButton(
                  onPressed: () =>
                      provider.setSelectedPosition("Start"),
                  child: Text("Start")),
              TextButton(
                  onPressed: () =>
                      provider.setSelectedPosition("Center"),
                  child: Text("Center")),
              TextButton(
                  onPressed: () =>
                      provider.setSelectedPosition("End"),
                  child: Text("End"))
            ],
          ),
          Consumer<PositionProvider>(builder: (context, value, child) =>
              Column(
                crossAxisAlignment: provider.getSelectedPosition == "Start"
                    ? CrossAxisAlignment.start
                    : provider.getSelectedPosition == "Center"
                    ? CrossAxisAlignment.center
                    : CrossAxisAlignment.end,
                children: [
                  Text("Message"),
                  Html(data: provider.getHtmlContents)
                ],
              ),),

        ],
      ),
    );
  }
}

// my provider class
class PositionProvider with ChangeNotifier {
  String selectedPosition = "Start";
  String htmlContents =
      ''' <img src="https://i.picsum.photos/id/9/250/250.jpg?hmac=tqDH5wEWHDN76mBIWEPzg1in6egMl49qZeguSaH9_VI" alt="Girl in a jacket" width="500" height="600">''';

  String get getSelectedPosition => selectedPosition;

  String get getHtmlContents => htmlContents;

  void setSelectedPosition(String selectedPosition) {
    this.selectedPosition = selectedPosition;
    notifyListeners();
  }

  void setHtmlContents(String selectedPosition) {
    this.htmlContents = htmlContents;
    notifyListeners();
  }
}

[rrousselGit]

You can do:

Consumer<PositionProvider>(
  builder: (context, value, child) {
    return Column(children: [..., child]);
  },
  child: Html(data: provider.getHtmlContents),
)

[rrousselGit]

No it won't. If passed as "child" like described, it won't rebuild

[aniketsongara]

Consumer<PositionProvider>(builder: (context, value, child) =>
              Column(
                crossAxisAlignment: provider.getSelectedPosition == "Start"
                    ? CrossAxisAlignment.start
                    : provider.getSelectedPosition == "Center"
                    ? CrossAxisAlignment.center
                    : CrossAxisAlignment.end,
                children: [
                  Text("Message"), // it will change position on each button click also same text widget below I want to change position on each button tab as described in above example 
                ],
              ),
          child: Column(
            children: [
              Html(data: provider.getHtmlContents),
              Text("Message"), // but now it is not rebuild but it should also change it's position as above text widget is changing   
            ],
          ),)

[rrousselGit]

Don't place the Column as "child"
Only place "Html"

[aniketsongara]

I want view like :- TextView then Html and the TextView and both Textview need to rebuild on each button press. can you explain through the code snip will be more helpful

[aniketsongara]

anything ??