Events and Data Band

Important

Scripts can be a security risk, so they are disabled in the Interpretation mode. However, if you are confident in the safety of your scripts, you can use them in the Compilation mode.

In addition to the events available for all components, the Data band provides three special events: BeginRenderEvent, EndRenderEvent, and RenderingEvent. These events are available because the Data band is rendered once for each data row in the specified data source. For example, if the data source contains 10 rows, the Data band is rendered 10 times. The BeginRenderEvent event occurs before the Data band begins rendering, before any data rows have been printed. You can use this event to initialize data or variables and perform other required actions. The EndRenderEvent event occurs after the Data band has finished rendering, when all data rows have been printed. It is typically used to process data and calculation results. Finally, the RenderingEvent event occurs when an individual data row is being rendered. It is triggered before the Data band is printed. If the data source contains 10 rows, the RenderingEvent event is triggered 10 times. To calculate the number of items in the data source, add the following code to the BeginRenderEvent event:

Calculate a number of elements in the data source. Write the following code in the BeginRenderEvent:

myvariable = 0;

Also it is necessary to create the myvariable variable in the data dictionary. Write the following code in the RenderingEvent:

myvariable = myvariable + 1;

And the EndRenderEvent is not used in this case. As a result of calculation the myvariable will store the value that is equal to the number of elements in the data source. To output this value in the Text component the following expression will be used:

{myvariable}

Also it is necessary to set the ProcessAtEnd property of the Text component to true. It is necessary to output the calculated value in the myvariable.