Endpoint Interface

Using the Endpoint Interface

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

.