The articles in this section of the Knowledge Base involve working with Groups for display in reports. To learn more about Groups and how to access the Report Designer, see Understanding Groups in the Report Designer. This article details Events in regards to Groups.

Just like with a Data band, the Group Header band has three specific rendering events available. While Rendering Events are applied to individual Data Rows when assigned to the Data band, when assigned to the Group Header band, the events are applied to groups.

To access these events, select the Group Header band and select the Events button  at the top of the Properties window. 

1. Begin Render Event
   

The Begin Render Event is called at the beginning of a new group being output. This event can be used for the initialization of data or variables, or for calling certain actions.

1. End Render Event
   

The End Render Event is called after the group is rendered. Data processing and the calculation of totals are usually performed in the handler of this event.

1. Rendering Event
   

The Rendering Event is called when the report generator is rendering one data row from a group.

The following tutorial provides an example for working with these events:

1. Create the “counter” variable in the Data Dictionary.
   
1. Select the Page tab > select Panels > select Dictionary.
   


Fig. 02 – Dictionary



2. Select New Item > New Variable.
   


Fig. 03 – New Variable



3. From the New Variable window, create a new int type variable named “counter.” Assign it a value of “0.” See Figure 04.
   


Fig. 04 – New Variable Dialog



2. Close the Dictionary Window > select the Group Header band for the event to be applied to > select the Events tab > write the following code in the Begin Render Event:
   

counter = counter + 1



Fig. 05 – Render Events




The counter variable increases by one each time a new group is rendered. The report in this example is grouped by materials, so counter is keeping track of the number of materials in the report.


3. Enter the following expression into a Text Component where you want the counter value to be displayed:
   

{counter}



Fig. 06 – “counter” Text Component




This has been entered into the standard Footer band for the entire report. 

4. Process the report. The results should look something like Figure 07. 
   


Fig. 07 – Report Example