Com.H.Threading.Scheduler.DI 10.1.0

Com.H.Threading.Scheduler.DI

Dependency injection extension for Com.H.Threading.Scheduler — provides IServiceCollection integration for .NET worker services hosted as Windows services, Linux daemons, or containerized microservices.

Visit the GitHub page for full documentation.

Quick start

1. Create the XML configuration

scheduler.xml

<?xml version="1.0" encoding="utf-8" ?>
<tasks_list>
  <task>
    <sys>
      <time>11:00</time>
    </sys>
    <greeting_message>Good morning! It's 11:00 AM!</greeting_message>
  </task>
</tasks_list>

2. Register the scheduler in DI

Program.cs

using Com.H.Threading.Scheduler;

var builder = Host.CreateApplicationBuilder(args);

builder.Services.AddSchedulerService(options =>
{
    options.ConfigPath = Path.Combine(AppContext.BaseDirectory, "scheduler.xml");
});

builder.Services.AddHostedService<Worker>();

var host = builder.Build();
host.Run();

3. Inject and use in a worker

Worker.cs

using Com.H.Threading.Scheduler;

public class Worker : BackgroundService
{
    private readonly ILogger<Worker> _logger;
    private readonly ISchedulerService _scheduler;

    public Worker(ILogger<Worker> logger, ISchedulerService scheduler)
    {
        _logger = logger;
        _scheduler = scheduler;
    }

    protected override async Task ExecuteAsync(CancellationToken stoppingToken)
    {
        _scheduler.IsDue += async (object sender, HTaskEventArgs e, CancellationToken ct) =>
        {
            _logger.LogInformation(e["greeting_message"]);
        };
        await _scheduler.StartAsync(stoppingToken);
    }
}

Scheduling features

All scheduling features come from the base Com.H.Threading.Scheduler library (included automatically as a dependency).

Interval scheduling

Run every 3 seconds between 9:00 AM and 2:00 PM on specific days:

<sys>
  <time>09:00</time>
  <until_time>14:00</until_time>
  <interval>3000</interval>
  <dow>Monday,Thursday</dow>
</sys>

Scheduling rules

All rules compose — every condition must be true for a task to run.

Retry on error

<sys>
  <interval>10000</interval>
  <retry_attempts_on_error>3</retry_attempts_on_error>
  <sleep_on_error>5000</sleep_on_error>
</sys>

Variables

Built-in placeholders replaced at runtime:

Repeat

Execute a task multiple times with different data per iteration. Supports XML (default), JSON, CSV, and pipe-separated formats:

<sys>
  <interval>60000</interval>
  <repeat content_type="json" delay_interval="500">
    [
      {"id": 1, "name": "alice"},
      {"id": 2, "name": "bob"}
    ]
  </repeat>
</sys>
<message>Processing {var{name}} (ID: {var{id}})</message>

Repeat from external source

Chain content types to fetch and parse: uri > json, uri > csv, uri > xml, etc.

<repeat content_type="uri > json" delay_interval="500">
  https://api.example.com/users
</repeat>

File URIs are also supported:

<repeat content_type="uri > csv" delay_interval="500">
  {dir{uri}}/data/users.csv
</repeat>

External settings

Fetch tag content from URLs with optional caching:

<config content_type="uri" content_cache="once_per_day">
  https://api.example.com/config
</config>

Cache options: none (default), once_per_day / daily, or milliseconds (e.g., content_cache="60000" for 60 seconds).

Dynamic scheduling with URI — skip holidays

content_type="uri" also works on scheduling rules inside <sys>. Point <enabled> at an API — if the response contains true (case-insensitive), the task runs; otherwise it's skipped:

<sys>
  <time>09:00</time>
  <dow>Monday,Tuesday,Wednesday,Thursday,Friday</dow>
  <enabled content_type="uri">https://api.example.com/is-business-day?date={now{yyyy-MM-dd}}</enabled>
</sys>

Add content_cache="once_per_day" to avoid calling the API on every tick — the result is cached until midnight:

<enabled content_type="uri" content_cache="once_per_day">https://api.example.com/is-business-day?date={now{yyyy-MM-dd}}</enabled>

Custom placeholder markers

Override the default {{ / }} markers on any tag:

<sql open-marker="[%" close-marker="%]" null-value="N/A">
  INSERT INTO users (name, email) VALUES ('[%var{name}%]', '[%var{email}%]')
</sql>

Error handling

Worker.cs

_scheduler.TaskExceptionError += async (object sender, HTaskExecutionErrorEventArgs e, CancellationToken ct) =>
{
    _logger.LogError($"Task failed: {e.Exception.Message}");
};

_scheduler.TaskLoadingError += async (object sender, HErrorEventArgs e, CancellationToken ct) =>
{
    _logger.LogError($"Config error: {e.Exception.Message}");
};

See the full documentation for more examples and details.