MongoEMF 0.5.1 Released

I have released MongoEMF version 0.5.1.  MongoEMF is a bridge between MongoDB and the Eclipse Modeling Framework making it very easy to store and retrieve instances of EMF objects in MongoDB.  This version is a maintenance release with bug fixes and minor enhancements.  For a complete list of new features, please see the Release Notes.  A Google group is now available for community discussions of MongoEMF.

MongoEMF 0.5.0 Released

I have released version 0.5.0 of MongoEMF.  MongoEMF is a bridge between MongoDB and the Eclipse Modeling Framework making it very easy to store and retrieve instances of EMF objects in MongoDB.  This version includes the ability to provide custom data type converters for storing non-native attribute values as a native type in MongoDB.  For example, you can now store a Calendar as a long.  The code was also refactored into a builder pattern, giving you the ability to completely customize how objects are serialized and deserialized in the database.  For a complete list of new features, please see the Release Notes.  I have also made some progress on a User Guide.  If you have any interest in contributing to this project, please contact me.

Google Summer of Code 2012 with Xtext, EMF, and MongoDB

The Eclipse Google Summer of Code for 2012 will start coming to life soon, and I have an idea for a project involving Xtext, EMF, and MongoDB.  Ed Merks and I have created a project called MongoEMF that allows you to persist EMF objects to MongoDB.  MongoEMF has the ability to query objects based on attribute and reference values, but is lacking some functionality and robustness.  We think a re-write of the query engine using Xtext and EMF would make for a great Google Summer of Code project.  This project has a very well defined scope, is easily unit tested, and involves some pretty cool technology.

The project will consist of two major parts.  The first will be to define a query grammar (possibly re-using an existing grammar) using Xtext.  The result will be an EMF query model that can be serialized and de-serialized to a string.  The string will be used as the query portion of a URI, and must be human readable.  For example:  mongo://host/db/collection/?(tag == ‘java’ || tag == ‘JSON’) && (category == ‘Eclipse’).  Clients will be able to specify the query as string or EMF model.  The second part of the project will be to create a processing engine that builds a MongoDB query from the EMF query model.  The result will be a DBObject that can be sent to MongoDB as a query.

An example use-case is as follows:  A client constructs an EMF query model.  The query model is then serialized to a string and included in a URI.  The URI is sent to a server in a HTTP GET call.  The server extracts the query string from the URI and re-builds the EMF query model.  The query model is passed to the query engine and a DBObject is returned containing a MongoDB specific query.  The DBObject is sent to MongoDB resulting in some number of DBObjects returned.  The resulting DBObjects are converted into EMF objects and returned to the client.

The student is expected to develop extensive unit tests for his / her code as well as end-user documentation.  Documentation will be contributed to the UserGuide on the MongoEMF wiki.  We also anticipate that the student will become a committer on MongoEMF, and will continue to provide bug fixes and enhancements after the project is complete.

We consider this to be an advanced Eclipse project.  The student should already be comfortable coding in Java and developing OSGi bundles with Eclipse.  A student with working knowledge of EMF will be preferred, but you are not required to already know Xtext or MongoDB.  If you are interested in this project, I would recommend forking the MongoEMF project on GitHub and experimenting with the latest code in the master branch.  Instructions for setting up your environment can be found on the Development wiki page.  If you have any questions, please comment on this post.

This project idea will be included on the Eclipse Google Summer of Code wiki soon.

eTrack EMF Tutorial

I’ve made a little more progress with eTrack and I now have two complete EMF tutorials available.  Creating the Entity Domain Model walks you through creating an EMF ecore model for the Entity domain, the corresponding genmodel, and how to use the generated editor.  Refactoring the Entity Domain Model shows you how to refactor an EMF model into two separate models.  These are the first tutorials available in a series that will cover the building of an entire application.  If you would like to contribute to the project, please let me know or open an issue.

Restlet Extensions for OSGi Environments 0.5.0 Released

I have released Restlet Extension for OSGi Environments version 0.5.0.  This project provides a framework for building RESTful OSGi web services using dynamic applications, routers, filters, and resources.  The project has been renamed from Restlet integration with OSGi & Equinox, and has also been refactored to be a Restlet extension.  This build is temporary until the extension is officially released as part of Restlet.  This release requires Restlet 2.1M7 or later.

MongoEMF 0.4.0 Released

I have released MongoEMF 0.4.0.  Some of the notable changes include:

  • Reading objects from a query Result has been significantly improved
  • Write performance for bulk stores has improved
  • Added MongoResourceImpl for improved load performance when using URI mappings
  • Added OPTION_USE_ID_ATTRIBUTE_AS_PRIMARY_KEY to store objects using the ID attribute value as the MongoDB primary key

For a complete list of the changes, see the Release Notes.