Difference between revisions of "Data Filter"

Revision as of 09:41, 24 August 2010

A key feature of Presence is the ability to filter data based on exception rules. These exception rules allow you to trigger different actions within a Presence Task depending on what has happened with your business data. For example, to perform different functions when new, changed or deleted data is detected.

Exception reporting is vastly superior to historical reporting methodologies where large daily and weekly reports are produced and the recipient must sift the data manually looking for exceptions.

Presence Deviation Engine

The technology that enables this facility is called the Presence Deviation Engine (PDE). The Date Filter task element allows the configuration of the PDE data change or exception rules.

Certain Presence Task elements, such as the Object Monitor and POP Scanner have PDE technology built into them allowing you to automatically filter out files / e-mails which have been processed before.

For all other types of data - for example data returned by an SQL Query, XML Query or Web Service Call you create PDE exception rules by adding a Data Filter node.

Creating a Data Filter

To create a Data Filter in your Task just drag the Data Filter Task Element into your Task from the Data Access List:

http://www.international-presence.com/wikidocs/images/data_filter_element.png

Snapshot or Base Data

The Data Filter takes a snapshot of the data returned by your SQL or XML queries. This snapshot we refer to as the PDE "Base Data". When a Task runs again, it checks the Base Data against the new data from the query. Depending on the rules you have setup in the Data Filter it can then take one or more different actions. For example we can take one set of actions if there are New rows of data, another set of actions if data has Changed, another if we find that some data has been removed from the list and so on.

Without a Data Filter node, Presence will continually report on all items returned by the query.

The Base Data is NOT saved until the task has completed. If a task fails due to an exception error (either in Debug Mode or live) the Base Data is not updated.