Learning Pentaho CTools

Using preExecution and postExecution

The preExecution and postExecution functions are very similar concerning their usage, but different in their purposes.

The first one, preExecution, you can see as preparing the execution of the component. One really good example is to point to another data source, or even to a different CDA file. Let's suppose you have multiple queries that are used in multiple dashboards, and you want to have a simple file where all the common queries are placed. This is possible to change with just a couple of lines of code in the PreExecution function.

Another good example is when you want to have cascading parameters. Let's suppose you want to have a selector where you can choose between the market level (country or city), ...