Routing Interface

Using Routing

cursors, refer to Chapter 11, "Data Storage and Retrieval." Note that only these
three cursor methods are supported for use with cursors returned by

GetTargetCursor

.

Note that

GetTargetCursor

works with any kind of target data, whether or not

it's a cursor. So you don't need to call

TargetIsCursor

to check before calling

GetTargetCursor

.

Here's an example of a

RouteScript

method that uses

GetTargetCursor

to

operate on multiple items:

MyActionFunc := func(target,targetView)

begin

local curs := GetTargetCursor(target,nil);
local e := curs:Entry();
while e do begin

:DoMyAction(e); // do the operation
e := curs:Next();

end;
// update display here

end;

Handling No Target Item

21

If the target item returned by

GetTargetInfo

is

nil

, this indicates that no target

item is selected or there is nothing to do when the Action button is pressed. In this
case, the system displays a warning message to inform the user of that fact. To take
advantage of this warning message feature, all application-specific routing actions
must be disabled when there is no target. (You may want to include some actions
even when there is no target; in this case, you can ignore this section.)

To disable application-specific routing actions when there is no target, you can do
one of two things:

Define a

GetTitle

method in the

routeScripts

frame for each action,

instead of a

title

slot. Then return

nil

from the

GetTitle

method to

prevent that action from showing up on the picker.

Define a

GetRouteScripts

method in your application, instead of a

routeScripts

slot. Then return

nil

or an empty array from the

GetRouteScripts

method to prevent any actions from showing up on

the picker.

Note that there are different messages displayed when there is no target item (the
target is

nil

) and when there are no actions available for the target item.