About Web Messenger
Web Messenger notifies other applications about changes to records in Vernon CMS.
For example, you can export records to another application, and then use Web Messenger to send the latest data when a record changes.
Other applications may include:
•Vernon Browser
•Your website’s content management system
•Your digital asset management system
An application that receives and reads the messages is called the listener.
Capturing changes and sending messages
Web Messenger captures saved changes in your records, such as:
•Object records
•Person records
•Photo/Audio-Visual records
The list of changed records is kept in a queue.
Processing messages in the queue
The queue helps to control the volume of messages. Web Messenger processes messages in the queue and prepares them for the listener.
The queue also manages messages if there is a problem with the listener. Messages will remain in the queue until the listener can receive them.
Communicating messages to the listener
A program called the packager takes the list of records from the queue and puts them together in a way that the listener can understand.
The packager then sends those messages to the listener.
•The packager can only send messages from workstations that have been set up as Web Messenger Servers, such as supervisor workstations or an indexing machine.
•The sending function should be turned off when the listener is down. For example, when maintenance is being performed on Vernon Browser.
Updating records in the listener
The listener reads each message and updates the relevant records. This can include updating, adding, or deleting records.
Vernon Browser requirements
•You must be using Vernon Browser 2.0.9 or later.
•You need to export your records first using the XML Export function of the Reporting tool.
•Web Messenger only captures changes to the Object, Person, Exhibition Venue, Topic, and Photo/Audio-Visual files as these are the only files currently supported in Vernon Browser.
Queue processing modes
Queues can process messages in two ways: synchronous and asynchronous. The queue for Vernon Browser uses asynchronous mode.
Synchronous mode
•Synchronous means ‘at the same time’.
•The order of messages is important.
•The listener is looking for a particular change in a particular field.
•A message is created each time a record is saved
•The messages are processed in the order they are placed in the queue using the data as at the time the record was saved.
Asynchronous mode
•Asynchronous means ‘not at the same time’.
•The order of messages does not matter.
•The listener will update the whole record with the latest data.
•Only one message per record will be posted in the queue
•The latest data for the record is used when the message is sent.
Web Messenger windows
See also
Webinar: Web Messenger - A video about Web Messenger on YouTube.
