Overview:
This field is evaluated once for each flowitem at the time the flowitem is ready to be sent to the next object. In a Processor object, the flowitem is ready to be sent at the end of its processing time. In a Queue, the flowitem is ready to be sent after the batch has accumulated and has been released.
The SendToPort expression must return a valid output port number. The output port will be opened, and the port number will be assigned to the flowitem. The flow item will then be pushed (or pulled) when the port connection becomes ready (output port and connected downstream input port are open). In the special case where the SendToPort expression returns a 0, all output ports will be opened, and the flowitem may leave through the first ready port. If the object is configured to reevaluate sendto, then this field is also evaluated every time a downstream object becomes ready to receive a flowitem. If the function returns a -1, then the flowitem will not be released at all, and should be released later on using the releaseitem() command, or should be moved out using the moveobject command.
Access variables:
current: the current object
item: the object that is ready to be sent
