Flutter path_provider local storage

Flutter allows you to easily implement local storage. Below is the sample code for local storage in flutter.

The sample code below we used the path_provider package to access the device’s file system. We also use the file class to manipulate files. Also, use the jsonEncode() method to convert the data to json format. I also use a textfield widget to let the user enter data and re-render when the state changes.

import 'dart:convert';
import 'dart:io';

import 'package:flutter/material.dart';
import 'package:path_provider/path_provider.dart';

void main() {
  runapp(myapp());
}

class myapp extends statefulwidget {
  @override
  _myappstate createstate() => _myappstate();
}

class _myappstate extends state<myapp> {
  string _text = '';

  @override
  void initstate() {
    super.initstate();
    _loaddata();
  }

  void _loaddata() async {
    final directory = await getapplicationdocumentsdirectory();
    final file = file('${directory.path}/data.txt');
    if (await file.exists()) {
      final data = jsondecode(await file.readasstring());
      setstate(() {
        _text = data['text'];
      });
    } else {
      setstate(() {
        _text = 'no data';
      });
    }
  }

  void _savedata() async {
    final directory = await getapplicationdocumentsdirectory();
    final file = file('${directory.path}/data.txt');
    await file.writeasstring(jsonencode({'text': _text}));
  }

  @override
  widget build(buildcontext context) {
    return materialapp(
      title: 'flutter local storage',
      theme: themedata(
        primaryswatch: colors.blue,
        visualdensity: visualdensity.adaptiveplatformdensity,
      ),
      home: scaffold(
        appbar: appbar(
          title: text('flutter local storage'),
        ),
        body: center(
          child: textfield(
            decoration: inputdecoration(hinttext: 'enter text'),
            onchanged: (text) {
              setstate(() {
                _text = text;
              });
            },
          ),
        ),
        floatingactionbutton: floatingactionbutton(
          child: icon(icons.save),
          onpressed: _savedata,
        ),
      ),
    );
  }
}