Thymeleaf - Best practice for checking for NULL when formatting (ie. dates)

Question

I have a Thymeleaf template code to format a date. There are times when that date will be null in the returned object. What is the best way to check for null in Thymeleaf in this situation? Currently the template is throwing the following error:

Caused by: java.lang.IllegalArgumentException: Cannot apply format on null     at org.thymeleaf.util.Validate.notNull(Validate.java:37)     at org.thymeleaf.util.DateUtils.format(DateUtils.java:182)     at org.thymeleaf.expression.Dates.format(Dates.java:164) 

Answer 1

You can also use a conditional expression on your object, so that the formatting method is only applied if you object is not null: th:text="${myDate} ? ${#dates.format(myDate,...)}"

Note there is no "else" part in the expression above, and in that case the expression will simply return null (making the th:text attribute write nothing).

(Disclaimer required by StackOverflow: I am the author of thymeleaf)

Answer 2

you can either use thymeleafs objects utility class Objects or validate the object before passing it to the template.

i prefer the prevalidation as you normally do not want to hack around in your template. also that way you keep your data loosely coupled from the view.