How to Schedule Background Corn Job in Flutter

In this example, we are going to show how to schedule a background corn job in Flutter to execute some code or task repeatedly, or at some specific time. Corn job are important to schedule any task. See the example below:

First, add corn Flutter package to your project by adding the following lines on pubspec.yaml file:

dependencies:
  flutter:
    sdk: flutter
  cron: ^0.4.0

Import package to script:

import 'package:cron/cron.dart';

How to Schedule Corn Job on Flutter:

final cron = Cron();

cron.schedule(Schedule.parse('*/1 * * * *'), () async {
   //your task code to execute
});

'*/1 * * * *' is a corn job expression, some of the corn job expressions are:

Corn Job Expression Format:

Some Corn Job Expressions:

You can generate your own corn job expression at corntab.guru.

Full Flutter Code Example:

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

void main() {
  runApp( MaterialApp(
       home: Home()
  ));
}

class Home extends  StatefulWidget {
  @override
  State<Home> createState() => _HomeState();
}

class _HomeState extends State<Home> {
  int counter = 0;
  final cron = Cron();


  @override
  void initState() {
    scheduletask();
    super.initState();
  }

  scheduletask(){
    //schedule repeated corn job every 1 minute
    cron.schedule(Schedule.parse('*/1 * * * *'), () async {
      counter++;
      setState(() {
        
      });
    });
  }
  @override
  Widget build(BuildContext context) {
    return Scaffold(
         resizeToAvoidBottomInset: false,
         appBar: AppBar(
            title: Text("Schedule Corn Job"),
            backgroundColor: Colors.deepPurpleAccent,
         ),
          body: Container(
             margin: EdgeInsets.only(top:30),
             alignment: Alignment.center,
             padding: EdgeInsets.all(20),
             child: Column(
               children: [

                   Text("Auto Counter: $counter", style:TextStyle(fontSize: 40)),
               ],
             ),
          )
      );
  }
}

Output Screenshot:

In this way, you can schedule a corn job in the Flutter app.