Add Start/Stop services

Applies to Tegral Web and Tegral DI Services.

Tegral DI Services has an internal mechanism for any component that needs to perform actions when started and/or stopped. This mechanism can be used by any component registered in Tegral DI (including anything you put in a Tegral Web application).

The Tegral DI Services extension

tip

Skip to the next section if you use Tegral Web.

Services are powered by an extension of Tegral DI. This extension is automatically installed if you use Tegral Web, but you will need to install it yourself if you use Tegral DI stand-alone.

Add a useServices() call to your Tegral DI block, e.g.:

tegralDi {
    useServices()

    // ...
}

Moreover, you will need to manually instruct Tegral DI when to actually start or stop components. You will need to call the .env.startAll() and .env.stopAll() functions whenever appropriate.

val env = tegralDi {
    useServices()
    // ...
}
env.services.startAll()
// At this point, Tegral DI has called `start` on all registered service components
// ...
env.services.stopAll()

tip

Because services use suspending functions, you'll need to use a coroutine to start and stop your services. If you are not running startAll or stopAll from a coroutine already, you can use the following to start and stop services instead:

runBlocking { env.services.startAll() }
// ...
runBlocking { env.services.stopAll() }

Services

Declaring services is done by implementing TegralDiService in a component.

Here's an example:

class MyFakeService : TegralDiService {
    override suspend fun start() {
        println("Starting service!")
    }

    override suspend fun stop() {
        println("Stopping service!")
    }
}

To register this service, put it like any other component:

// With standalone Tegral DI
tegralDi {
    useServices()
    put(::MyFakeService)
}

// With Tegral Web
tegral {
    put(::MyFakeService)
}

For more information on what is available with Tegral DI Services, see this page.