Name
NSAssertionHandler — Mac OS X 10.0
Synopsis
The NSAssertionHandler
class is responsible for
assertions that are created using the Foundation framework assertion
macros. Every thread has its own assertion handler object that is
obtained through the class method currentHandler
.
NSAssertionHandler
provides the methods
handleFailureInMethod:object:file:lineNumber:description
:
and
handleFailureInFunction:file:lineNumber:description
:
to log error messages in response to assertion failures within
methods and functions, respectively.
The assertion macros allow the user to check
for a given condition—that is, assert that a condition must be
true—and if the condition is false, a string is passed to the
assertion handler, and the handler is notified of the failed
assertion. When the assertion handler receives notification of a
failed assertion it will print an error message that includes the
user-specified string, as well as the class and method names where
the assertion failure occurred. Additionally, an
NSInternalInconsistencyException
is raised. If
this exception is not handled by the application, the application
will exit.
The Foundation framework defines six assertion macros that can be
used within an Objective-C method (NSAssert
,
NSAssert1
, NSAssert2
, etc.) and
six macros that may be used within a C function
(NSCAssert
, NSCAssert1
,
NSCAssert2
, etc.). Each of these macros takes a condition that will be asserted, and a string that will be printed as part of the error message. The numbered ...
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