Elevator is a object oriented pluggable data-layer for Perl, built on top of MooseX::Declare.
Elevator makes it easy to do data-driven OO. Elevator is a scaffolding for making and using objects that lets you stop thinking about how they are stored. You work with elevator by subclassing it, it is not a module that you just instantiate instances of.
Elevator objects all have built-in ability to load and save themselves to JSON or raw perl datastructures. Additional roles may be added to objects to allow them to be serialized to-and-from a database, memcache, or NoSql.
For instance, one could simultaneously use multiple NoSQL datastores without having to know the quirks of either, or use sqlite locally and MySQL on a different environment.
It's also much lighter than most ORMs. Code looks like code. There's no configuration.
To begin work with elevator, first create a subclass of Elevator::Model::BaseObject that returns subclasses of WA::Drivers::* that return suitable SQL, NoSQL, and Memcache connections for your data environment. See the examples directory for how to proceed. All further model classes in your application will then inherit from your new BaseObject subclass(es).
The examples directory shows how to do this and includes a test program that drives some of these objects.
Just do what the examples do.
Elevator provides some shorthand ('data', 'attr', and 'lazy') around Moose attribute boilerplate. Attributes must be flagged with 'data' to show up in the serializer or database/NoSql saving.
Lazy is a shortcut around Moose's excellent lazy loading, and attr is a thin wrapper around Moose's has. You should really read the Moose tutorials to fully understand things.
Elevator does not hide Moose from you, it just makes some things simpler.
The Elevator team likes comments, but dislikes pod. Expect to see some more user-level and generated API documentation shortly, but do read the code. Elevator wishes that you understand how it works (so you can become a contributor), and there's not really much to it.
Prerequisite libraries are listed in the Bundle directory. Otherwise, just make sure Elevator if findable via PERL5LIB. CPAN package pending.
run "make" in a checkout to run the full test battery.
Tests will assume MongoDB and sqlite are available, and will try to hit memcache all on localhost. If they are not available, you may have some minor things to change.
Many features specific to the original implementation have been removed to make this a more general purpose module. These include typed exception handling and specialized sharding support. A generalized method of supporting these for existing sites and web frameworks didn't make sense, so you may wish to add these in your own way by subclassing any of the existing classes. Sharding is still possible on a class-by-class basis, but is not yet really supported as a 1st class concept.
Elevator is MIT licensed open source software. See COPYING for more details.
For now, send bugs at patch requests to github.com/webassign, you will need a github account.
Until a discussion list is available, feel free to email mpdehaan@webassign.net.
Elevator was originally created by Michael DeHaan for http://webassign.net/, and contains some differences in this release to make it more generic than the original.
- Michael DeHaan <michael.dehaan@gmail.com/mpdehaan@webassign.net>
- Mike Morella
- Shawn Page
- Robert Johnson
- Ben Wheeler
Send in a patch to get your name here.