MOD IDEA: A Singleton Registry
out having to change your code. This solves most of the problem but it doesn't allow you to subclass a singleton object. Take this bit of code for instance: use Singleton::Foobar; $obj = Singleton::Foobar->instance(); What if you decided that you need to subclass Foobar at some later point, and that your code needs to use the subclass? Well you end up needing to change a lot of code. So the point of the registry is to create a layer between the singleton and the calling code so that subclasses can be entered into the system seamlessly without any pain. So what you end up with is the ability to share instances of an object throughout your application. You get the ability to easily subclass to swap out certain classes with others and don't need to change the calling code. On top of all of that you also get the ability to store application and site wide configuration information in a single place to save you maintenance headaches in the future. I dunno, that sounds like a good thing to me which is why I built it.. =item Current/Planned Registry Singletons Class::Singleton::Registry::DBI - A DBI singleton, supports multiple instances based on name (currently in development). Class::Singleton::Registry::Session - A singleton based on Apache::Session, it will support multiple instances. Has not yet been started. Class::Singleton::Registry::AppSession - A singleton based on Apache::Session, it will support multiple instances. Has not yet been started. =item Creating Singletons Creating a singleton that can be used with the registry is very straightforward and simple. It must have an init() method, a getInstance() method, and a lastError() method. The type of object returned, the caching mechanism, and all other details are up to the singleton class author. =head1 AUTHOR Robert Hanson <[EMAIL PROTECTED]>
RE: MOD IDEA: A Singleton Registry
Yeah, looks like it's a match. Thanks. Rob > -Original Message- > From: Tatsuhiko Miyagawa [mailto:[EMAIL PROTECTED]] > Sent: Saturday, March 16, 2002 9:51 AM > To: Robert Hanson > Cc: [EMAIL PROTECTED] > Subject: Re: MOD IDEA: A Singleton Registry > > > On Sat, 16 Mar 2002 06:54:31 -0500 > [EMAIL PROTECTED] (Robert Hanson) wrote: > > > This is something I have been putting together for a project > and I didn't > > see anything comparable on CPAN. Looking for comments, > suggestions, and any > > existing modules that may duplicate the functionality. > > Object::Registrar? > http://search.cpan.org/search?dist=Object-Registrar > > > -- > Tatsuhiko Miyagawa
Seeking CPAN account
name: Robert Hanson email: [EMAIL PROTECTED] homepage: none preferred user-ID: RHANSON description of what you're planning to contribute: XML::RAX - A module based on Sean McGrath's RAX proposal http://www.xml.com/pub/2000/04/26/rax/index.html. DSLI entry: adpO 44 character description: Record-oriented API for XML It would be very nice, if you could also send a note... The idea came from the the RAX article by Sean McGrath which was posted on XML.com Friday (4/29). I had never heard of RAX before, so I sent a mail to Sean asking where to find the RAX spec and mentioned my interest in creating a Perl module for it. He replied urging me to write the module, and mentioned that there is no official spec of RAX. If RAX takes off, he plans on writing up an official spec and hosting a web site for it. It has only been 36 hours since the article came out on XML.com, so I doubt there has been much discussion about the usefulness of RAX. By the time you get this, I should have already sent out a mail to ActiveState's XML-Perl list and XML-DEV announcing this module. Thanks, Robert
ANNOUNCE: XML::EasyOBJ
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NAME
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XML::EasyOBJ - Easy XML object navigation
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VERSION
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Version 1.0
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SYNOPSIS
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# create the object
my $doc = new XML::EasyOBJ('my_xml_document.xml');
# print some text from the document
print $doc->some_element(1)->getString;
# print an attribute value
print $doc->some_element(0)->getAttr('foo')."\n";
# iterate over a list of elements
foreach my $x ( $foo->some_element ) {
print $x->getString."\n";
}
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DESCRIPTION
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XML::EasyOBJ lets you take an XML page and essentially
create an object out of it. Each element becomes a
method, which makes it really easy to navigate an XML
page (if you know the structure). The motivation behind
this module was to create an interface so simple that
anyone who knows the basic functionality of Perl can
learn how to read data from an XML document in less
than 10 minutes.
This module is also a time saver even if you are
familiar with the other modules available, but want
something simple so that you can throw together a
script in a few minutes (unless of course you know the
DOM like the back of your hand).
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REQUIREMENTS
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XML::EasyOBJ uses XML::DOM. XML::DOM is
available from CPAN (www.cpan.org).
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INSTALLATION
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This module installs in the normal way...
perl Makefile.pl
make
make install
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AUTHOR/COPYRIGHT
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Robert Hanson ([EMAIL PROTECTED])
Copyright 2000, Robert Hanson. All rights reserved.
This library is free software; you can redistribute
it and/or modify it under the same terms as Perl itself.
