Handling Report Events

One of the methods for expanding reports functionality is handling events occurred when the user works with a report.

An event handler enables the user to execute a specified operation each time the event occurs. For example, on connecting an event handling unit, the following options become available:

Working with Event Handling Units

To connect an existing event handling handler:

Execute one of the operations:

Click the Select Unit button.
Select the Select Unit from Repository item in the drop-down menu of the Actions button.

Select unit on the Navigator side panel.

After executing the operations, the unit is added to the list if units:

Set parameters in the Event Handling section:

Unit. In the drop-down list select the unit containing class implementation for regular report events handling or select the Set Handler item in the drop-down menu of the Actions button in the list of units.
Class. In the drop-down list select the class inherited from the ReportEvents class that contains implementation of methods for handling regular report events. The list of classes is generated depending on the selected unit. Event handler class description can be created automatically.

Event handler class can have the constructor called at each class initialization. The designer must not contain parameters. If the class has several constructors without parameters, the first constructor is called that is located above the others in the code.

NOTE. Event class is initialized each time when an action is executed in the report. In this case wither one event or a chain of events can be generated.

After executing the operations, the selected event handling unit is connected to the regular report.

NOTE. Only one event handling unit contained in the list if units can be connected to the report.

To create a unit implementing regular report event handling, execute one of the operations:

Click the Create Unit button.
Select the Create Unit item in the drop-down menu of the Actions button.

After executing one of the operations the new unit is created in the object navigator in the folder with the regular report and is opened in the development environment to be filled with code.

To create a unit implementing the EventsClass class with templates of handlers of all regular report events , execute one of the operations:

Click the Create Handler button.
Select the Create Handler item in the drop-down menu of the Actions button.

After executing one of the operations the new unit is created on the object navigator in the folder with the regular report, added to the list of units and opened in the development environment to be filled with code.

To reset the connected event handing unit, execute one of the operations:

Select the Reset Handler item in the drop-down menu of the Actions button in the list of units.
Click the Reset Handler button in the Unit parameter.

After executing one of the operations the current event handler is reset.

To open the event handling unit in the development environment, select the Open in Development Environment item in the drop-down menu of the Actions button in the list of units. After this the selected unit will be opened in the development environment.

To remove the connected event handling unit from the list of units, select the Remove item in the drop-down menu of the Actions button. After this the action confirmation dialog box opens. If the answer is positive, the selected unit will be removed from the list of units.

Besides events handling, a unit can implement custom functions to transform data. If the list of units contains such a unit, custom functions will be available in the function wizard on creating a formula.

Example of Event Handler

To execute the example, create a unit. Add links to the Drawing, Express, Report, and Tab system assemblies.

Sub Main;
Begin

End Sub Main;

Class EventsClass: ReportEvents
...
    // Event that occurs after regular report sheet calculation
    Public Sub OnAfterRecalcSheet(Sheet: IPrxSheet);
    Var
        Tab: ITabSheet;
        Range: ITabRange;
        Style: ITabCellStyle;
    Begin
        // Get report sheet table
        Tab := Sheet As ITabSheet;
        // Select cell range for highlightin
        Range := Tab.Cells(0, 0, 10, 5);
        // Set formatting style for selected range
        Style := Range.Style;
        // Set cell background fill for selected range with green color
        Style.BackgroundBrush := New GxSolidBrush.Create(GxColor.FromName("Green"));
    End Sub OnAfterRecalcSheet;
...
End Class EventsClass;

As a result, when the event occurs that follows regular report sheet calculation, background of the A0:F10 cell range is filled with green color.