Apple Newton Programmer’s Newton 2.0 (for Newton 2.0) - Manual (Page 847)

C H A P T E R 2 3
Endpoint Interface
Using the Endpoint Interface 23-19
Handling Unexpected Completion 23
The CompletionScript message is sent to the input spec frame when the input
spec completes unexpectedly—for example, because of a time-out expiring or a
Cancel message.
If you do not specify a CompletionScript method in your input spec frame, an
exception is forwarded to the endpoint ExceptionHandler method.
Special Considerations 23
If you want to set up an input spec, but you never want to terminate the input, you
can set up the input form to be either
'string or 'bytes data, and not define
any of the data termination conditions. In this case, it is up to you to read and flush
the input. You can do this by using a
PartialScript method that calls the
FlushPartial method at the appropriate times. Note that if the input exceeds
the discardAfter size, the oldest data in the buffer is deleted to reduce the size
of the input.
Alternatively, if you omit the InputScript method, yet define the input data
form and termination conditions, the input continues to be terminated and flushed
at the appropriate times. The only difference is that without an
InputScript
method, you'll never see the complete input.
Receiving Data Using Alternative Methods 23
The methods described in this section allow you to receive data in ways other than
letting an input spec terminate normally. You may not need to use these methods;
they're provided for flexibility in handling special situations.
You can force the system to send a pending input spec the InputScript message
by calling the Input method. Note that this method is appropriate to use only
when receiving data of the forms 'string and 'bytes . Also, in an InputScript
method that is called as a result of calling Input , you cannot use SetInputSpec
to change or terminate the input spec. Instead, you must first send the Cancel
message to cancel the current input spec.
You can look at incoming data outside the scope of your InputScript or
PartialScript method by calling the method Partial . This method returns
data from the input buffer but doesn’t remove it from the buffer. You can use this
method to sample incoming data without affecting the normal operation of your
input spec and its callback methods. Note that this method is appropriate to use
only when receiving data of the forms
'string and 'bytes .