ControlContext :: emitMessage - Emit Message
The function sends a text message to a user control. When the control associated with the control context is not a user control, the function does nothing. In order to obtain messages in a user control, the user control has to re-implement the UserControl ::message() function.
{
//..fragment
field('user_control').setProperty(phVideo);
field('user_control').emitMessage('start animation');
//..
}