Inter-plugin Events

In API V9Preview2, the ability to create and use custom events was added.

For this purpose, the following operations were introduced:

• GetExternalNotificationSubscription
• InvokeExternalNotification
• GetAllExternalNotificationsNames

GetExternalNotificationSubscription(string subscriptionName) - this operation allows you to subscribe to a custom event named subscriptionName. If the event does not exist, it will be registered and subscribed to immediately. The maximum length of the event name is 256 characters.

Usage example:

IDisposable subscription;
subscription =	
	PluginContext.Operations
		.GetExternalNotificationSubscription(subscriptionName)
		.Subscribe(Console.WriteLine);

GetAllExternalNotificationsNames() - this operation allows you to retrieve a list of the names of all events registered on the terminal.

InvokeExternalNotification(string subscriptionName, string notificationData) - this operation triggers a custom event notification named subscriptionName for all its subscribers and transmits information in text format as notificationData. The maximum length of the information is 32,000 characters.

Usage example:

var subscriptionName = PluginContext.Operations.GetAllExternalNotificationsNames().Last();
PluginContext.Operations.InvokeExternalNotification(subscriptionName, Guid.NewGuid().ToString());

It is important to know that events are shared across all terminals in the group, which allows notifications to be sent not only to local plugins but also to plugins on other terminals. Additionally, an event notification can be triggered from any plugin within the terminal group, even if the plugin itself is not subscribed to that event.

A usage example of custom events has been added to the SamplePlugin.