/ 
hub-standard-04.00.012
/ hubuse

NAME

hubuse - Using the Hub library

SYNOPSIS

The Hub module represents functions and classes which are implemented in descendant packages. Hub dynamically loads modules according to the parameters it is used with.

DESCRIPTION

Don't use the underlying modules directly:

use Hub::Base::FileSystem;    # Wrong
use Hub;                      # Correct

my $parser = Hub::Parse::FileParser->new('my.template');    # Wrong
my $parser = Hub::mkinst('FileParser', 'my.template');      # Correct

Without getting into gory detail, this non-standard approach is in place for three reasons:

1)  Allow the library to be refactored (maintained) without impacting existing
    code.

2)  We don't want to short-circut Perl's built-in require functionality which
    would be necessary, were we to support direct underlying module usage.

3)  We only want to load underlying modules when they are needed.  We want to
    group related modules in the same subdirectory. The subdirectory name 
    will then be used as the import tag which loads its modules.

Module Directory Structure

By default, Hub tries to be as efficient as possible, only loading packages which are necessary.

Subdirectories are used to group exported modules. Underneath the root (Hub) directory, are sub-directories which represent the export tag of which the underlying modules should be represented.

Hub/:
  |-Base/:
  |-Util/:
  `-Webapp/:

Descendant packages maintain their exported symbols in their EXPORT_OK array. The Hub module proxies these exported symbols, thus requiring all descendant- exported symbols to be unique.

Classes are created with the Hub::mkinst using their short-name. Thus requiring them to be unique (to other classes):

1. Hub::Custom::Class.pm       # defines function 'new'
2. Hub::Another::Class.pm      # doesn't define 'new'
3. Hub::Yetagain::Class.pm     # also defines 'new'

#1 and #3 will clash because they are both classes, but either can be used with #2 simultaneously.

AUTHOR

Ryan Gies (ryangies@livesite.net)

COPYRIGHT

Copyright (C) 2006-2007 by Livesite Networks, LLC. All rights reserved.

Copyright (C) 2000-2005 by Ryan Gies. All rights reserved.

Redistribution and use in source and binary forms, with or without modification, are permitted provided that the following conditions are met:

* Redistributions of source code must retain the above copyright notice, this list of conditions and the following disclaimer.

* The origin of this software must not be misrepresented; you must not claim that you wrote the original software. If you use this software in a product, an acknowledgment in the product documentation would be appreciated but is not required.

* Altered source versions must be plainly marked as such, and must not be misrepresented as being the original software.

* The name of the author may not be used to endorse or promote products derived from this software without specific prior written permission.

THIS SOFTWARE IS PROVIDED BY THE AUTHOR "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.

To the best of our knowledge, no patented algorithms have been used. However, we do not have the resources to carry out a patent search, and therefore cannot give any guarantee of the above statement.

UPDATED

06/09/2007