Routing Interface

Using Routing

The

VerifyRoutingInfo

method is passed two parameters, the target

information frame obtained by

GetTargetInfo

, and the partially initialized item

frame obtained from

NewItem

. The

VerifyRoutingInfo

method allows you a

chance to verify or change the target item before the routing slip is opened.
Normally you would return the same target frame that was passed in, possibly
modified. To cancel the routing operation, you can return

nil

from this method.

Note that the system sends the

VerifyRoutingInfo

message only if it is imple-

mented by your application; otherwise, the routing operation continues without it.

If multiple items are being routed, the target object (constructed by

CreateTargeCursor

) encapsulates them all. In your

VerifyRoutingInfo

method, you can use the function

GetTargetCursor

to return a cursor to

navigate the items. Then you can iterate through the cursor using the cursor
methods

Entry

,

Next

, and

Prev

, as described in Chapter 11, "Data Storage and

Retrieval." Note that only these three cursor methods are supported for use with
cursors returned by

GetTargetCursor

.

Getting and Setting the Current Format

21

Next, the Routing interface sends your application base view the

GetDefaultFormat

message. The purpose of this message is to get the default

format so that when the routing slip is opened, the format can be initially set to the
default. Normally, the default format for a particular transport is simply the last
format used with that transport from that application. This information is stored in
the

lastFormats

slot of your application base view. Unless you want to do

something special, you don't need to implement the

GetDefaultFormat

method

because this is a root view method that is found by inheritance. The root view
method simply gets the default format symbol from the

lastFormats

slot.

The format can be changed by the user, or by the system (if no last format is found,
the default is set to the first one that is found). When the format is changed, the
Routing interface sends your application base view the

SetDefaultFormat

message. The purpose of this message is to store the default format symbol for later
use. Normally, this is stored in the

lastFormats

slot in the application base

view. Unless you want to do something special, you don't need to implement the

SetDefaultFormat

method because this is a root view method that is found by

inheritance. The root view method simply sets the new format symbol in the

lastFormats

slot of your application base view.

The

lastFormats

frame contains a slot for each transport that has been used

from your application. Whenever a transport is selected, the system first checks
your application for the

lastFormats

frame and for a slot within that frame

named with the symbol of the transport being used. If the slot is found, it contains
the symbol of the last format used by that transport. Then the system searches for a
format whose

symbol

slot matches it.