To continue evolving towards DSpace 2.0 goals this year, @mire will continue to provide further refactorings of the DSpace legacy codebase. These refactoring efforts are focused now on resurrecting and completing the the DAO prototype work of past Hewlett Packard developer, James Rutherford. This work includes efforts to separate the legacy DSpace codebase into a separate Domain Model and Data Access Services. Once integrated into DSpace 1.8, new DSpace Services for legacy DSpace objects will provide a common API for both the DSpace Application tier and external addon modules.

Find out more about this project in the Development Proposals section of the DSpace wiki.

https://wiki.duraspace.org/display/DSPACE/The+TAO+of+DSpace+Services

Cheers,
Mark

1.) Look in the correct locations for dspace.cfg and local properties. There were problems with these that just were not evident in the Unit testing.

2.) Use of the classpath*: Resource resolution scheme when searching the classpath for dspace-core-services.xml spring files. This allows DSpace Addon Modules to Properly introduce Services , Activators and Beans into the Spring ServiceManager for use in DSpace

Find out more at:
http://wiki.dspace.org/DSpace+Services+Framework
http://static.springsource.org/spring/docs/2.5.x/reference/resources.html

These new features should make creating DSpace Addon Modules a little bit more accessible.

However, just a few lines lower we see.

This infers that once we have the Service manager, we can now acquire just about any service we need to work with in the initialization and runtime activities of the current module, theres much less of a need to inject.

I find this very inspiring. I think this will be the bridge point between DSpace Services and OSGi / SpringDM environments. The predominant concern however, is that the ServiceManager shouldn’t be interrogated until it is properly started, which happens after Spring has finished initializing.  So we should restrict ourselves from using it to wire bean properties in place of Spring.  In fact, we should avoid retaining references to the services outside the scope of its usage within the class.

My recommendation now for DSpace Services is to go through and start to limit the current usage of DI within Services to the Addon Module Project the Service Resides in. Not that we can’t use it within the context of the DSpace Addon Modules configuration for defining implementation centric DI Configuration. But just that we should define best practices concerning the boundaries that we should expose Service wiring across. Take for instance, the following as still a valid practice:

I think that maybe its better to reserve the power of  Spring IoC / DI to the same scope as its applied in SpringDM, utilizing it to act to initialize resources locally within the bundle. I think the real power of this is that when services are truly delivered by something like OSGi Bundles, making sure that our Addon Modules get their services from the ServiceManager at Runtime and not from Spring at instantiation time will assure that much of the code depending on these services will not need to change when DSpace is run in an OSGi environment.

While one always cringes at viewing oneself in video, I’ll post the video stream as well for those that are interested in working with the dspace services framework.

User Group Meeting Site: http://dsug09.ub.gu.se/index.php/dsug/dsug09
Crowdvine: http://dsug09.crowdvine.com/
Video Streaming: http://bambuser.com/channel/dsug09

May 20th, 2009

Session One

DuraSpace –  Michele Kimpton and Sandy Payette

http://presentations.dlpe.gatech.edu/or09/or09_052009_1/index.html

Session Two

DSpace Technology Overview – Bradley McLean

Repository Software Technical Update with Chris Wilper – Chris Wilper

http://presentations.dlpe.gatech.edu/or09/or09_052009_2/index.html

Session Three

2.0 Demonstration – Ben Bosman

http://presentations.dlpe.gatech.edu/or09/or09_052009_3/index.html

Session Four

XMLUI Modularity in DSpace 1.5 & 2.0 – Mark Diggory

DSpace 1.5 Modifications:  A Technical Overview – Elliot Metsger

DSpace 2 Service Manager Framework – Aaron Zeckoski

http://presentations.dlpe.gatech.edu/or09/or09_052009_4/index.html

Session Five

Designing and Implementing a Learning Object Repository – William E Moen

Using DSpace as a Disciplinary Data Repository – Ryan Scherle

Introducing Vireo – ETD Submittal and Management for DSpace – Adam

Mikeal, Scott Phillips, John Leggett, Mark McFarland

The Sustainability, Preservation, Accessibility of Internal and

External Communities by Universities – Jeffrey Trimble and Salvador

Barragan

http://presentations.dlpe.gatech.edu/or09/or09_052009_5/index.html

May 21st, 2009

Session One

Depth Customization of DSpace – S.K. Vijaianand and V.D. Shrivastava

http://presentations.dlpe.gatech.edu/or09/or09_052109_1/index.html

EIAH’s Experience in Localization and Customization of DSpace – Emad

Khazraee, Saeed Moaddeli and Hamed Malek

http://presentations.dlpe.gatech.edu/or09/or09_052109_2/index.html

The Myth of Federated Searching – OhioLINK Digital Resoursce Commons

Team

http://presentations.dlpe.gatech.edu/or09/or09_052109_3/index.html

Session Two

Making DSpace 1.5 Your Own: Customizing Via Overlays – Tim Donohue

http://presentations.dlpe.gatech.edu/or09/or09_052109_4/index.html

DSpace Global Outreach Committee Update – Valorie Hollister

http://presentations.dlpe.gatech.edu/or09/or09_052109_5/index.html
]]> http://mdiggory.wordpress.com/2009/05/28/open-repositories-dspace-user-group-presentations/feed/ 1 mdiggory http://mdiggory.wordpress.com/2009/05/23/dspace-2-0-entities-and-service-domains/ http://mdiggory.wordpress.com/2009/05/23/dspace-2-0-entities-and-service-domains/#comments Sat, 23 May 2009 21:42:00 +0000 mdiggory http://mdiggory.wordpress.com/2009/05/23/dspace-2-0-entities-and-service-domains Continue reading →]]> This last weeks OR09 meeting unleashed a number of new epiphanies around DSpace 2.0. I feel these realizations should lead us to the next step in way we represent entities like DSpace Items.

One of these ideas has to do with the recognition that an Item is actually a “View” or a “Join” of properties from separate functional areas such as “content”, “history”, “policy”, and “presentation”. Here are a few examples of those areas.

1.) Content: An underlying store in DSpace might be JCR, Fedora, DSpace, and s3. Each of these maintain a separate model expressing content their domain. Fedora (Fedora Objects and Datastreams), JCR (JCR Nodes, JCR Properties, JCR References), DSpace (Collections, Communities, Items, Bundles, Bitstreams, etc).

2.) History: Each of these above storage systems presents Versioning, History or Provenance differently in its above ER (Entity Relationship) model. While the Content domain may provide a representation of that versioning history, there is still the requirement of a separate service layered (or not layered) on top of that to work with the at Versioning model.

3.) Policy: Certainly each of these expresses a set of policy information, which is generally managed in a separate service or layer on top of the Entities expressed therein.

4.) Presentation: Once you have these expressed, external tools will seek to have varying “expressions” of the previous 3 areas that are specific to a particular domain/tool (HTML, AJAX/Web 2.0, OAI-PMH, LOD, ATOM/APP) Some of these various communities seek to constrain what out of the previous 3 areas can be expressed within their transmissions.

I feel that being at the nexus of all these functional domains, DSpace 2.0 has an opportunity to be something very powerful. If we can recognize that the “presentation” of any DSpace 2.0 Entity is a JOIN of the data from each of these areas, and that we have different “Services” responsible for expressing, accessing and persisting that “domain specific” data, then its clear that for any one entity in the DSpace model that we actually have N possible domain specific representations of an Entity expressed.

Content: Content in an underlying stores model on a per Entity basis.
History: Provenance, Versioning, and Change History Trail in Harmony per Entity.
Policy: Access Control and other Policy rules per Entity.
Presentation: Rendering details specific to a serialization of the Entity.

For much of the week I had been battling if we would want to provide Access Control configurability on a per property basis in DSpace 2.0, such that one would set explicit access rights on each property (regardless of its “functional use”) in an Entity, it seemed that it could get very unwieldy, bloated and slow as the store grew. As an alternative, I was exploring mediating access control for only Entities on a per Service basis. Given the above analysis, I’m beginning to think this is the more reasonable approach.

To give an example, an Item might have a set of System properties, Descriptive properties, Provenance properties, and Policy controls; all stored in separate services. In DSpace 1.x provenance was stored directly in the metadata table (I.E. the Content Domain). Capturing changes on the “Content Domain” of the Item becomes difficult to mediate rights on because the changes themselves get encoded as changes in the “Content Domain” of the Item.

Work was ongoing at MIT by Mackenzie Smith to separate out that change history into an independent service based on a “history” triple-store.  This is actually the right direction we should be going in for DSpace 2.0 and I think we may now see the correct path to integrate not just the work completed in the Pledge project into DSpace 2.0, But also possibly some of the significant work completed in last years Google Summer of Code on Fedora integration and Versioning of DSpace Items.

http://google.com/support/webmasters/bin/answer.py?hl=en&answer=99170

http://rdfa.info/2009/05/12/google-announces-support-for-rdfa/

http://radar.oreilly.com/2009/05/google-announces-support-for-m.html

For DSpace, this means we need to pay attention to semantic markup in our Items. I think for DSpace 2.0 this will be “key”. DSpace 2.0 Entities align cleanly with RDF Resources. It will be very exciting to see how this synergy gives rise to publishing and describing our content in as much detail (or in as little detail) as we like! Pay attention to our presentation at the upcoming OR09 Conference next week to see how @mire and the DSpace Foundation have partnered to get DSpace 2.0 off the ground and ready for this brave new world.

]]> http://mdiggory.wordpress.com/2009/05/14/google-announces-support-for-rdfa-rich-snippets/feed/ 0 mdiggory http://mdiggory.wordpress.com/2009/05/14/moving-the-dspace-svn-repository-to-oregon-state-university-open-source-lab/ http://mdiggory.wordpress.com/2009/05/14/moving-the-dspace-svn-repository-to-oregon-state-university-open-source-lab/#comments Thu, 14 May 2009 21:51:00 +0000 mdiggory http://mdiggory.wordpress.com/2009/05/14/moving-the-dspace-svn-repository-to-oregon-state-university-open-source-lab Continue reading →]]> After over 6 months of working closely with the Oregon State University Open Source Lab (many thanks to Jeff Sheltren, Rudy Grigar, and Lance Albertson of OSUOSL) we’ve migrated the DSpace S.F. SVN repository to a custom CentOS Virtual Server at OSL.

This move is to spearhead an initiative to consolidate and scale the three open source SVN repositories we maintain into one repository under one roof. The primary goal being to create an environment where our community can begin to scale, delegate access rights, and management responsibilities of specific portions of our codebase. Something we cannot attain with existing SourceForge and GoogleCode free resources. The DSpace community is a diverse, international and growing and we have a need for scalable solution that will grow with us in both Access Control and performance. OSL became an obvious choice for both its personal approach to hosting Open Source projects and its position in the academic community on Internet2. OSL provides excellent hosting solutions for many Open Source Initiatives!

From this point forward http://scm.dspace.org/svn/repo will house the contents of the following repositories:

http://dspace.svn.sf.net/svnroot/dspace
http://code.google.com/p/dspace-sandbox

Eventually we will consider adding the contents of http://code.google.com/p/dspace-gsoc if it is deemed relevant (which it may seem with our recent GSoC acceptances). Please come and comment if you have an interest in participating in the community on our listservs.

What are the requirements for participating in GSoC 2009!?? Find out here (professors, show this to your students)…

(ok, kinda dry, but gets to the point right away, “Google Will Give You Money!”).

And more propaganda here!!!

The purpose of participation is to (1) promote involvement of new students as open source developers within the DSpace Community, (2) provide opportunities for existing community members to lead within the community as mentors, and (3) build some exciting new add-ons and prototypes for DSpace along the way, .

We would like to encourage “all community members” to post their ideas for projects on the wiki: Google_Summer_of_Code_Ideas. To see ideas from 2008 for reference: Summer_of_Code_Ideas_2008

We need to get as many ideas posted by MARCH 24th, as this is when the application period begins for students (applications are accepted until Fri, April 3, 12pm PST) If you are interested in participating as a student If you would like to be a mentor on the project you proposed, are an active developer in the community and keenly interested in leading a student through a software development project, join the community and apply in the GSoC 2009 application as a mentor for the DSpace project.

Get excited and join in on the fun!