Publishing Methods

Business objects offer methods to retrieve information or perform a specific action for a business object. For publishing, the available methods are PublishList, PublishChanges and UnpublishChanges.

The client application sends the PublishList or PublishChanges request to LN and will be listening to the communication channel (bus component) that will be used to transfer the resulting data.

Upon PublishList, a process is started that collects the data in accordance with selection and filter. The business objects are published by publishing messages containing the data to the listener. In case of a large data set, multiple messages can be sent. The client applies the data to its own database and removes instances that are missing (so they are not relevant anymore). This process stops as soon as it completed processing the whole data set in accordance with the specified selection and filter.

The selection specifies what parts (attributes) of a business object must be published. For example, the order number, order date and status from an order and the line number, item, quantity and price for each order line. The filter specifies what instances of the object and its components must be included. For example, only include orders having status ‘open’ and only include order lines having a quantity more than 10.

Upon PublishChanges, a process is started that detects any new events (either create, change or delete events). Events that meet the specified selection and filter are published. The process is stopped by invoking the UnpublishChanges method. The settings are changed by invoking the PublishChanges method using a different selection and/or filter.

The client receives the data set or change events and takes action upon these. For example, by synchronizing its own database or by starting an application process based on an incoming event.