Spring Thymeleaf Tips | Part 1

We’ve been developing a UI using Spring Thymeleaf (2.1.2) on our team. I’ve noticed a serious dearth of examples outside of specific questions on Stack Overflow, so I figured I’d throw my hat in the ring and offer a few tips and tricks we’ve picked up over the 10 or so months working with this templating system. This is part one of a series. In each exploration, we will examine a few different pieces of Thymeleaf that could make your life a little easier. This first one is a few tips and tricks that should help keep your templates a little more readable.

Make Function Calls Into Your POJOs

Sometimes we need a little more power behind our retrieval operations. When it’s too complicated to try and manage it inline or Thymeleaf’s expressions don’t cover your use case, you can always use a formatter method on your domain object and call that directly in the template.

Let’s say we have a list of people with addresses, and we want to format the second address field on its own line if it’s there. We could use a ternary operator for that in a big messy concatenation, but for the sake of readability, it’s easier to wrap it in a function and let the model serve up the formatted text.

This markup produces:

Use Ternary Operators for Unreliable Info

Sometimes you run across a case where a piece of data isn’t present yet in the state of your application. In some of these cases, clever use of the ternary operator can make for an inline data swap instead of having to use th:if or th:block.

Use RowStat to Grab the Index Th:Each

There’s a secondary argument available to th:each – rowStat. It allows you to access certain values around the collection you are iterating over.

Use Th:Field for Fun and Profit

If you don’t want to type the name of your input over and over again, use th:field. It turns this:

into this:

Use Th:Object for Cleaner Templates

For a specific block of code, you can use th:object to allow direct reference to an object’s members. Once we do that to our table, it looks like this:

Note the change in the notation from ‘$’ to ‘*’. This tells Thymeleaf to look up the tree for a parent object.

That’s all for today. Next time we’ll cover standard expression libraries, Java 8 time expressions, data types and integrating Thymeleaf service objects with your javascript.