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), and the second filter will show you countries or cities depending on what you have selected for the first one. The first will drive the query for your second filter, and so the values to select will vary between country or city. The following code...