Event Service |
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Process Platform contains the provision for monitoring the activities of any entity within the Process Platform framework. An entity can be any resource in the framework. When any party within Process Platform wants to monitor the activities occurring in an entity, it can do so by subscribing to these activities using event service. This is called Event subscription. The requesting party is called the Event subscriber. The entity whose activities are being monitored is called subject. Every activity occurring in the subject is published to the subscriber. The activities occurring in the subject are called events.
Event Service publishes all the events that occur over a subject within Process Platform to the subscriber. It maintains a list of subscribers per subject. The user can choose to subscribe or unsubscribe to a subject. If the event service fails to deliver an event to any of the subscribers, that subscriber is immediately unsubscribed. An example of event subscription is loading applications using Application Manager. As the installation of the application progresses, many messages are displayed at the bottom of the screen. These messages usually indicate the status of the installation and these messages are called events.
Another usage of event service is the mail exchange client. The user need not perform any special operation to check if a new e-mail is received after opening the inbox. New messages alerts are automatically displayed to the user.
Event Service is also very useful while debugging in Process Platform.
Event service also persists subscriber information, that is, it maintains the subscriber information in the wcp.properties file as a collection per subject. For more information on persisting event service subscriptions, refer to Persisting Event Service Subscriptions.
Event Service Connector
Process Platform provides you with the 'Event Handling Service Connector' while creating service containers to work with event service.
The 'Event Service' application connector publishes all the events that occur in Process Platform. For more information on Event Handling Service Connector APIs, refer to Event Service Connector APIs.
Eventservice in Ajax Toolkit
Process Platform also provides you with Eventservice APIs that can be used in the User Interface (UI). These APIs can be used while developing applications to take advantage of the event service feature. For more information, refer to Eventservice.