$Id: Options.pod,v 1.6 2004/03/25 19:27:59 tower Exp $
=head1 Setting Options
C<:asycnz> sets options by means of named parameters for both the parent process
and each of its child processes. Options for the parent are set in C<:asycnz-e>new>.
Options for the child processes are set via the C parameter of C<:asycnz-e>new>;
the value of this parameter must be an array of C<:z3950::asyncz::options::_params>
If a C<_params> object doesn't exist for a child process, C<:asycnz-e>new>
will create it with a set of default options. There will always be a C<_params>
object for every server in the C array, and they are cross-indexed, that is
C<$_params_object> is used for C<$server>, etc. So, if you are creating your
own array of C<_params> objects, you must keep this parallelism in mind.
=head2 Types of Options
Options set in C<:z3950::asyncz::new> which control the parent process
and selected features of the child processes for which no alternatives
are present: the alternatives are set as indicated in  and .
Options set in a C<:z3950::asyncz:options::_params> object: this is returned
by C<:z3950::asyncz::asynczoptions>. There is one C<_params> object
for each server: if you don't create one, it is created for you with
the default values. If you don't create a C<_params> object for
a server, then C and C options set in the C
constructor will be used. The rationale behind this is that you usually will
be asking one question across all servers and will usually be using only
one log file for debugging.
But in all other cases where it is possible
to set an option for the child in both the C constructor or
C<_params>, the C<_params> setting will be used. At the moment this affects
the C and C options.
Options set in the C<:z3950::manager> by using the C
option of the C<_params> object. These take precedence over any others
and must be passed in with the first C<_params> object, that is, C<$_params_object>,
because AsyncZ uses only one C<:z3950::manager>. The Manager
is created when setting up the first server passed into the constructor.
Default values for options are shown to the right of the C<=E>operator:
In some instances, the I of variable is shown and defaults detailed in commentary:
EEEcallback function to which records will be sent as available.