You might have noticed my recent blog posts are of a Java nature, and that’s not like me. I’m currently on a Java project, so that means everything is a fun new world of learning (and pain) 🙂
On the project, one of the early tasks is navigation as you would expect. As I need to tackle this task soon, I started to look around the web for patterns and practices others have followed. Unfortunately I didn’t really find much information on navigation in DD4T Java (there are a few posts for .Net), so I decided I’d give it a go.
Before I start, I would first like to highlight a few caveats
- I am not a seasoned Java developer. I am from a .Net background, so please don’t be too harsh
- This is a pre-release view of the research (and self-learning) I have been doing in my spare time. The code will probably look quite different by the time it makes it to production on my project.
Now, lets begin
Why Share so Early?
I decided to share this early for two main reasons:
- You can help me improve it
- Others working on Navigation for DD4T 2 Java may also be looking for ideas on how to get started
For the approach, I decided to follow the same pattern as DD4T employs for retrieving items from SDL, using factories and data binders. It makes it a little more future proof, when things inevitably change.
So far it all seems to be working quite well, however I do still have several todo’s in the code which need some attention.
I’m a fan of developing to a contract, to decouple my application tiers. So, the first step was to define a Json structure I am happy with, and make that the contract between SDL Web and my DD4T application.
The specifics of your Json contract are up to you (and your requirements), but here is a simple example
Now, working from the bottom up, I needed to define models to correspond with my contract. I ended up with
With the foundations in place, I needed to implement the data binding layer, to de-serialize my Json to POJOs.
I also added a factory, to plumb in the data binding process
Keeping it plugable, next I created a factory
I decided to go with a dedicated navigation controller
The last piece of the puzzle (excluding the configuration) was the View.
For now I am outputting it via a JSP include. I plan to investigate the DD4t SmartInclude tag as an alternative.
With all the code in place, the last step was configuration.
Add a url-pattern to your dispatcher servlet mapping
Add the following section (replacing any x’s of course)
I hope this was useful, and please feel free to ask me (tweet me as I’ll see it sooner) any questions.