package SVN::Base;

=head1 NAME

SVN::Base - Base class for importing symbols for svn modules

=head1 SYNOPSIS

    # Load the svn_ra_* functions into the SVN::Ra namespace.
    pacakge SVN::Ra;
    use SVN::Base qw(Ra svn_ra_);

    # Load svn_config_t structure accessors in the magic namcespace
    # provided by swig, so we could use it returned by other functions
    package _p_svn_config_t;
    use SVN::Base qw(Core svn_config_);

=head1 DESCRIPTION

SVN::Base is a module importing the subversion perl bindings raw
symbols created by swig, into proper namespace and make them easier to
use.

It will also find the accessors for members of a C struct, create an
simpler accessor function like C<$data-E<gt>field()> and
C<$data-E<gt>field($new_value)>.

Once you understand the convention of subversion functions in perl
bindings, you could look at the subversion api and write them in perl.
The API is available in the source header files or online at
http://svn.collab.net/svn-doxygen/.

=head1 INTERNALS

The perl bindings of swig wraps raw functions into different perl
modules, for example, SVN::_Core, SVN::_Repos. Upon import, SVN::Base
bootstrap the requested module if it's not yet loaded, and iterate
over the symbols provided in that module, it them puts the function
with prefix trimmed in the namespace of the caller for this import.

The 3rd through the last parameter is a list of symbol endings that
you wish for SVN::Base not to import into your namespace.  This is useful
for cases where you may want to import certaion symbols differently than
normally.

=head1 CAVEATS

SVN::Base consider a function as structure member accessor if it is
postfixed ``_get'' or ``_set''. Real functions with this postfixes
will need extra handling.

=cut

sub import {
    my (undef, $pkg, $prefix, @ignore) = @_;
    no warnings 'uninitialized';
    unless (${"SVN::_${pkg}::ISA"}[0] eq 'DynaLoader') {
	@{"SVN::_${pkg}::ISA"} = qw(DynaLoader);
	eval qq'
package SVN::_$pkg;
require DynaLoader;
bootstrap SVN::_$pkg;
1;
    ' or die $@;
    };

    my $caller = caller(0);

    SYMBOL: for (keys %{"SVN::_${pkg}::"}) {
	my $name = $_;
	next unless s/^$prefix//i;
    foreach my $ignored_symbol (@ignore) {
        next SYMBOL if ("$prefix$ignored_symbol" eq $name);
    }

	# insert the accessor
	if (m/(.*)_get$/) {
	    my $member = $1;
	    *{"${caller}::$1"} = sub {
		&{"SVN::_${pkg}::${prefix}${member}_".
		      (@_ > 1 ? 'set' : 'get')} (@_)
		  }
	}
	elsif (m/(.*)_set$/) {
	}
	else {
	    *{"${caller}::$_"} = ${"SVN::_${pkg}::"}{$name};
	}
    }

}

=head1 AUTHORS

Chia-liang Kao E<lt>clkao@clkao.orgE<gt>

=head1 COPYRIGHT

Copyright (c) 2003 CollabNet.  All rights reserved.

This software is licensed as described in the file COPYING, which you
should have received as part of this distribution.  The terms are also
available at http://subversion.tigris.org/license-1.html.  If newer
versions of this license are posted there, you may use a newer version
instead, at your option.

This software consists of voluntary contributions made by many
individuals.  For exact contribution history, see the revision history
and logs, available at http://subversion.tigris.org/.

=cut

1;
