Apple Newton Programmer’s Newton 2.0 (for Newton 2.0) User Manual

Page 522

C H A P T E R 1 2

Special-Purpose Objects for Data Storage and Retrieval

12-16

Using Special-Purpose Data Storage Objects

Testing the Validity of a Mock Entry

The

IsMockEntry

global function returns the value

true

for objects that are valid

mock entries. You can use this function to distinguish between mock entry objects
and other objects such as cache frames or soup entries. Note that the

IsSoupEntry

function returns

true

for both mock entries and normal soup entries.

Getting Mock Entry Data

The

EntryCachedObject

global function returns the cached frame associated

with a specified mock entry. You can call this function to retrieve the cached frame
associated with a specified mock entry. For example, your handler frame’s

EntryChange

method must retrieve the cached frame in order to write it back to

a mock soup.

Changing the Mock Entry’s Handler

The

EntrySetHandler

function is a special-purpose function that you can use to

replace a mock entry’s handler. For example, you can use this function to install a
handler that implements debug versions of methods present in the mock entry’s
original handler frame. Such methods might include breakpoints and print
statements that would not be present in the commercial version of an application.

Getting the Mock Entry’s Handler

The system supplies the

EntryHandler

function for debugging purposes. The

EntryHandler

function returns a reference to the handler frame associated with

the mock entry specified by the value of the

mockEntry

parameter.

Implementing Additional Handler Methods

Your handler needs to provide additional methods that are the mock entry counter-
parts to system-supplied entry functions, such as

EntryUndoChangesXmit

, and

others. For a list of suggested methods that your handler may implement, see
“Application-Defined Mock Entry Handler Methods” on page 12-19.