CronScheduler.AspNetCore

The goal of this library was to utilize IHostedService interface for Asp.Net Core 2.1 for scheduled jobs/tasks. It is lighter than Quartz schedular and operates inside of any GenericHost.

Uses Crontab format for Jobs/Tasks schedules

This library does not include implementations for seconds in the Crontab format. You can use https://crontab-generator.org/ to generated needed job/task schedule. The following crontab format is supported:

*    *    *    *    *  
┬    ┬    ┬    ┬    ┬
│    │    │    │    │
│    │    │    │    │
│    │    │    │    └───── day of week (0 - 6) (Sunday=0 )
│    │    │    └────────── month (1 - 12)
│    │    └─────────────── day of month (1 - 31)
│    └──────────────────── hour (0 - 23)
└───────────────────────── min (0 - 59)

  `* * * * *`        Every minute.
  `0 * * * *`        Top of every hour.
  `0,1,2 * * * *`    Every hour at minutes 0, 1, and 2.
  `*/2 * * * *`      Every two minutes.
  `1-55 * * * *`     Every minute through the 55th minute.
  `* 1,10,20 * * *`  Every 1st, 10th, and 20th hours.

Example WebTestApp

The sample website provides with use-case scenario for this library.

Includes the following sample service:

 public class TorahQuoteJob : IScheduledJob
    {
        public string CronSchedule { get; }

        private readonly TorahService _service;
        private readonly TorahSettings _options;

        public TorahQuoteJob(IOptions<TorahSettings> options, TorahService service)
        {
            _options = options.Value;
            CronSchedule = _options.CronSchedule; //set to 1 min in appsettings.json "* * * * *"
            _service = service;
        }
        

        public async Task ExecuteAsync(CancellationToken cancellationToken)
        {
            var index = new Random().Next(_options.Verses.Length);
            var exp = _options.Verses[index];

            var result = await _service.GetVerses(exp, cancellationToken);

            TorahVerses.Current = result;
        }
    }

• Sample uses Microsoft.Extensions.Http.Polly extension library to make http calls every minute.

Special Thanks to

• Maarten Balliauw for the Asp.Net Core idea for the background hosted implementation.
• NCrontab
• 3 ways to use HTTPClientFactory in ASP.NET Core 2.1