Apple Newton Utilities Guide de l'utilisateur télécharger pdf (Page 764)

100

101

CHAPTER 21

Routing Interface

21-16 Using Routing

If you need to read the body slot within the fields frame, note that it might

contain an alias. In order to access it you must get the format and send it the

ResolveBody message, like this:

theFormat := GetCurrentFormat(fields);

resolvedBodySlot := theFormat:ResolveBody(fields);

The ResolveBody method returns the data in the body slot whether or not it is

referenced by an alias, so you can always use it.

You can store information you obtain from an auxiliary view in the

fields frame,

preferably in the

body slot (or if body contains an alias, in the entry the alias

points to). If you store data from the auxiliary view in a different slot, be sure the

slot name has your developer signature appended to avoid future slot name

conﬂicts.

Registering Routing Formats 21

All routing formats are speciﬁed as view deﬁnitions and are registered with the

system by means of the global function

RegisterViewDef. The formats that

handle data types other than

'view are not actually views, but they are registered

as view deﬁnitions to take advantage of the central registration mechanism.

Registering formats in this way makes them available to all applications in the

system. Routing formats are specially identiﬁed in the view deﬁnition registry

because the

type slot of all routing formats is set to the symbol 'routeFormat

(or

'printFormat in some ROM versions).

example of registering a format:

RegisterViewDef(myPrintFormat, '|myDataClass:SIG|);

This call registers the format myPrintFormat as working with data whose

class is

'|myDataClass:SIG|. If the class of any target data object is

'|myDataClass:SIG|, the format myPrintFormat will be available when

that item is routed. The fact that this print format (with a

'view data type) has

been registered means that you can print and fax that class of data items. This

mechanism enables you to have separate routing formats (and thus routing actions)

for individual views, if they use different data classes for data, rather than using the

same formats (and routing actions) for all views in an application.

Typically, your application registers routing formats when it is installed, in its part

InstallScript function, and unregisters formats in its RemoveScript

function. You use the function UnRegisterViewDef to unregister routing formats.

In an application part

InstallScript function, when registering your

routing formats, you must not use the Newton Toolkit function

GetLayout

to obtain a reference to the routing format layout, so that you can pass it to

1 2 ... 759 760 761 762 763 764 765 766 767 768 769 ... 941 942

Commentaires sur ces manuels

Pas de commentaire

Apple Newton Utilities Guide de l'utilisateur Page 764

Commentaires sur ces manuels

Produits connexes et manuels pour Logiciel Apple Newton Utilities