This means that you can generate a scaffold in a Rails application, go to the model, replace ActiveRecord::Base with ActiveLucene::Document and everything should be still working with the difference that the model should be being saved in a Lucene index rather than in a relational database.
As the documents are now being saved in a Lucene index, we can find them using the Lucene query syntax, without forgetting that as ActiveLucene has a similar interface to ActiveRecord, we can also find them by an id, find the first, find the last, etc.
The base class of ActiveLucene is called Document because as the documents of another systems, it doesn’t have a defined structure and all the attributes are dynamic, so you do not have to worry about them.
ActiveLucene was extracted from Lunr, a not-enterprise search server from which I will speak in a future post, but as today, it can also be used in applications where having a relational database doesn’t make much sense and especially in the ones where you want to search documents by text.
The restriction of ActiveLucene is that it only works with JRuby, since Lucene is a Java library that runs on the JVM. Case this isn’t a problem, using ActiveLucene should be much simpler and lighter than using a solution such as Sphinx or Solr, depending of the case this may result in great benefits.
Lucene has a lot of features and ActiveLucene doesn’t support them all, but they will be added to the project as needed. As today, there is support for highlighting and a little for paging, as can be seen in the following video, along with a basic demonstration of the tool: