Add toCronString function (#50)

CHANGELOG.md

@@ -1,5 +1,9 @@
 # Changelog
 
+## 0.6.0
+
+- Add `toCronString` function and improve package. [#50](https://github.com/agilord/cron/pull/50) by [mbfakourii](https://github.com/mbfakourii)
+
 ## 0.5.1
 
 - Fixed scheduling issue. [#42](https://github.com/agilord/cron/issues/42) by [ccl0326](https://github.com/ccl0326)

README.md

@@ -1,15 +1,17 @@
-# A cron-like time-based job scheduler for Dart
+# Cron
 
 Run tasks periodically at fixed times or intervals.
 
+[![pub package](https://img.shields.io/pub/v/cron.svg)](https://pub.dev/packages/cron)
+
 ## Usage
 
 A simple usage example:
 
 ```dart
 import 'package:cron/cron.dart';
 
-main() {
+void main() {
   final cron = Cron();
 
   cron.schedule(Schedule.parse('*/3 * * * *'), () async {
@@ -22,6 +24,20 @@ main() {
 }
 ```
 
+## Cron parser
+You can easily create and parse [cron format](https://en.wikipedia.org/wiki/Cron):
+
+```dart
+import 'package:cron/cron.dart';
+
+void main() {
+  print(Schedule.parse('3-5 * * * *').minutes); // [3, 4, 5]
+  
+  print(Schedule(hours: 12, minutes: 25, weekdays: [2, 3])
+      .toCronString()); // 25 12 * * 2,3
+}
+```
+
 ## Links
 
 - [source code][source]

lib/cron.dart

@@ -130,6 +130,31 @@ class Schedule {
       seconds != null &&
       seconds!.isNotEmpty &&
       (seconds!.length != 1 || !seconds!.contains(0));
+
+  /// Converts the schedule into a cron-formatted string.
+  String toCronString({bool hasSecond = false}) {
+    final minutesStr = _convertToCronString(minutes);
+    final hoursStr = _convertToCronString(hours);
+    final daysStr = _convertToCronString(days);
+    final monthsStr = _convertToCronString(months);
+    final weekdaysStr = _convertToCronString(weekdays);
+
+    if (hasSecond) {
+      final secondsStr = _convertToCronString(seconds);
+
+      return '$secondsStr $minutesStr $hoursStr $daysStr $monthsStr $weekdaysStr';
+    } else {
+      return '$minutesStr $hoursStr $daysStr $monthsStr $weekdaysStr';
+    }
+  }
+
+  String _convertToCronString(List<int>? list) {
+    if (list == null || list.isEmpty) {
+      return '*';
+    } else {
+      return list.join(',');
+    }
+  }
 }
 
 abstract class ScheduledTask {

pubspec.yaml

@@ -1,15 +1,22 @@
 name: cron
 description: A time-based job scheduler similar to cron. Run tasks periodically at fixed times or intervals.
-version: 0.5.1
-homepage: https://github.com/agilord/cron
+version: 0.6.0
+repository: https://github.com/agilord/cron
+
+topics:
+  - cron
+  - scheduler
+  - cron-parser
+  - schedule
+  - cron-time
 
 environment:
-  sdk: '>=2.12.0 <3.0.0'
+  sdk: '>=2.12.0 <4.0.0'
 
 dependencies:
-  clock: ^1.1.0
+  clock: ^1.1.1
 
 dev_dependencies:
-  pedantic: ^1.0.0
-  test: ^1.0.0
-  fake_async: ^1.2.0
+  pedantic: ^1.11.1
+  test: ^1.25.0
+  fake_async: ^1.3.1

test/cron_test.dart

@@ -42,4 +42,11 @@ void main() {
       expect(count, 1);
     }, initialTime: DateTime(2000, 1, 1, 0, 0, 0, 0, 0));
   });
+
+  test('should return correct cron format string.', () {
+    expect(
+      Schedule(hours: 13, minutes: 20, weekdays: [1, 2]).toCronString(),
+      '20 13 * * 1,2',
+    );
+  });
 }