Events Reference

Events can be published, subscribed, or created by an custom service, component model, or component.

Publishing Events

Events can be published by calling the .publish method on the event object.

In both components and services, event objects are accessed by injecting the relevant event reference class.

tip

The AllEvents class is a repository of all available events in the VertiGIS Studio Mobile SDK

class CustomServiceOrComponent : ServiceBase
{
    private AllEvents _events;

    private TaskEvents _taskEvents;

    public CustomServiceOrComponent(AllEvents events, TaskEvents taskEvents)
        : base()
    {
        _events = events;
        _taskEvents = taskEvents;
    }

    public void PublishSomeEvent()
    {
        _taskEvents.Identified.Publish(someFeatures);
        // _events.TaskEvents.Identified.Publish(someFeatures);
    }
}

Subscribing to Events

Events can be subscribed to by calling the .subscribe method on the event object.

In both components and services, event objects are accessed by injecting the event reference class.

Important

It is vital that subscription handles are cleaned up when the object is cleaned up, otherwise dangling references can occur. This can be done by implementing the IDisposable and IDisposableTracker interface, and then providing this as the second argument to a call to subscribe. ServiceBase and ComponentBase already implement these interfaces so you don't have to.

public class CustomServiceOrComponent : ServiceBase
{
    public CustomServiceOrComponent(UIEvents uiEvents)
    {
        uiEvents.ComponentActivated.Subscribe(_onComponentActivated, this);
    }

    private void _onComponentActivated(string id)
    {
        // ... do something on component activation
    }
}

Creating Custom Events

Custom events in VertiGIS Studio Mobile are created through the IEventRegistry. Events can be directly created in any component or service that can inject this class, but it is best practice to define events in a class that extends EventsBase and registers with Autofac. This allows your events to be injected and referenced by any component or service across the app.

[assembly: Export(typeof(CustomEvents), SingleInstance = true, AsImplementedInterfaces = false, AsSelf = true, PropertiesAutowired = true)]
namespace App1.Events
{
    public class CustomEvents : EventsBase
    {
        public IEvent SomeEvent => GetEvent("custom.some-event");

        public CustomEvents(IEventRegistry eventRegistry)
            : base(eventRegistry)
        {
        }
    }
}

Event Arguments

Events optionally take a type argument, which represents the object associated with the event consumed by the subscriber. This can be a simple or complex object.

public class CustomEvents : EventsBase
{
    public IEvent EventWithNoArg => GetEvent("custom.no-arg");

    public IEvent<string> EventWithSimpleArg => GetEvent<string>("custom.simple-arg");

    public IEvent<YourCustomType> EventWithComplexArg => GetEvent("custom.complex-arg");

    public CustomEvents(IEventRegistry eventRegistry)
        : base(eventRegistry)
    {
    }
}