PEAR_ErrorStack::pushCallback() -- Set an error Callback If set to a valid callback, this will be called
every time an error is pushed onto the stack. The return value will be
used to determine whether to allow an error to be pushed or logged.
PEAR_ErrorStack is an experimental error raising and handling implementation for PEAR that is designed
to replace PEAR_Error when it has stabilized. PEAR_ErrorStack is both backwards compatible with PEAR_Error
and forward compatible with PHP 5's Exception class. There are many other features, all described
in the Introduction.
Usage:
1 // global error stack
2 $global_stack = &PEAR_ErrorStack::singleton('MyPackage');
3 // local error stack
4 $local_stack = new PEAR_ErrorStack('MyPackage');