When the user has completed the form, he has to click a button to continue and process the entered data - the button click triggers the next process step.

So if you create forms for your process, you need to insert at least one button.

The example on the left shows a form with multiple buttons that are used to implement a decision.

Example:

In the ACME idea management process , the CEO has to decide if a reported idea should be implemented or not. Therefore the form IdeaCheck contains two buttons:

• Reject
• Approve

The different button events correspond to different possible process flows. Work with boundary events to define the additional process flows.

Example:

• If the CEO uses button Approve in the form, an approval mail should be sent. This is the default process flow, the process continues from the user task.
• If the CEO uses button Reject in the form, a rejection mail should be sent. This is the additional process flow, the process continues from the boundary event.

Use the attribute Trigger Event to define for each button in the form which process flow is to be triggered when clicking it.

The trigger event defines which button event should trigger the execution of the related element. You can find the attribute Trigger Event in the attributes panel of

• User Tasks
• Plain Events (if used as a boundary event)
• Message Events (if used as a boundary event)

Before you assign a trigger event, make sure that the form you want to use is assigned to the user task in the Form attribute. If no form is assigned, there are no trigger events available.

If the assigned form contains one button only, assign this button as trigger event on the user task to define the default process flow.

Example:

The Approve button is assigned to the user task Check idea .

Use the Trigger Event attribute of each boundary event, to define additional process flows.

Example:

The Reject button is assigned to the boundary event.

A button event cannot be assigned twice as a trigger on the same form. Once you have assigned it to an event or form, it is greyed out on the other element(s) and you cannot select it anymore.

Example:

The Approve button has already been assigned to the user task Check idea , therefore it is greyed out in the selection list of the boundary event.

However, it is possible to assign several trigger events to one BPMN element to ensure that multiple buttons can trigger the same process flow.