(Edit : I renamed this post so it doesn’t seem like Spigot is just for Seam, Spigot can be used with different frameworks or without any at all. However, I wrote this post since Spigot is so familiar to the Seam EntityQuery that it should be easy for Seam users to get the idea)

Seam developers should become familiar with Spigot concepts fairly quickly since they are very similar to those found in the Seam EntityQuery which was one of the main inspirations for the framework. If you imagine taking the entity query class and splitting it in two, one part to keep hold of state and the other to actually fetch the data. The stateful part is the Paginator that keeps track of what the current ordering of the data is, what is the current page and how big the pages are. The stateless part takes the Ejbql and the pagination information and returns a subset of the data. Now imaging that the data provider has the JPA pieces taken out and replaced with an abstract fetchResults method. This method is implemented in subclasses for specific data providers for text files, sql queries, jpa queries, native jpa queries, xml files, comma delimited or just an in memory dataset.

I also abstracted the concepts of parameterization and parameter resolution so you can have parameters on data providers that are no t query based and your parameters can be resolved using different mechanisms such as EL, reflection, a map, or using custom parameter resolution.
So really, for Seam developers, its like a Seam EntityQuery that doesn’t just use JPA, but uses any kind of data source you want but still returns just a list of objects.

Spigot works nicely with CDI and there is even a demo of it in the distribution that uses JSF and was generated using the Weld maven archetypes. Also, there is a Seam Jpa Dataset Adapter that you can use as a direct replacement for the EntityQuery which will adapt the entity query calls to the underlying data provider calls so you can have a seam-less transition if you want to switch over. This is still a little in-progress, but works. The one area that isn’t implemented is the sorting, which may not be possible, but I still need to add in the methods to the adapter even if they don’t do anything. The other issue is of course the configuration of the query from components.xml using the Seam Framework tags. However, you can define the query using regular component xml tags to define the Ejbql, restrictions and page sizes.

Two things to note if you start using Spigot in place of the entity query. All rows are returned by default, and you need to specify both a select statement and a count statement. I separated those two out so you can put join fetch phrases in the select statement without it breaking the count statement. There is an init method that you can use to set both of these statements for a class type.

Granted, source control and build management should have been done early on but this is a small project where I already make regular informal backups and the IDE handles building the single jar so I didn’t bother. Also, I wasn’t planning on making it open source originally but since I did, I wanted to get everything tidied away.

On top of that, I’ve had to produce documentation, more so than if I was just using the library myself, and produce wiki pages, provide uploads, test the downloads to make sure they work, check that the download will work when installed to a maven repository, and provide instruction on how to use it from a maven repository etc. It’s a lot of work all for the sake of sharing a project with the world. I wouldn’t have to do most of that if I were keeping it to myself!

However, it has taught me two things. One is to appreciate all the extra work that goes into managing an open source project above and beyond just putting a jar file on a web page for download. The other is a reminder to always start out with good practices (build processes and source control) from scratch if you even think the project might go public. This is a no-brainer if you know the project will be open source in advance, but probably should be followed just in case you decide to open source it later on.