I have some values in my database which can be null if they have not already been entered.
But when I use Thymeleaf in my html, it gives an error when parsing null values.
Is there any way to handle this?
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11 Answers
The shortest way is using '?' operator. If you have User entity with embedded Address entity in order to access fields of Address entity and print them if address is not null, otherwise here will be an empty column:
<td th:text="${user?.address?.city}"></td>
Note: this feature is from SpringStandardDialect, not the Thymeleaf standard dialect.
// call it if using thymeleaf without spring mvc
templateEngine.setDialect(new SpringStandardDialect())
9 Comments
rdguam
The
?. operator is called the "safe navigation" operator, per the Spring Expression Language docs.
keyboardsamurai
While the above syntax is accepted as valid in spring boot 2.0.5 that comes with thymeleaf 3.0.9, at least for me it does not do what is claimed here. Is that a special feature that you have to enable?
Dave
using ? on a numeric field that is 0 will also produce false. Thus you'd need to use the full != null conditional on number fields.
sarath
I get ognl.ExpressionSyntaxException: Malformed OGNL expression: error in SpringBoot 2.6
Aspiring Dev
I too get the same exception @sarath got. Using the same version of Spring Boot.
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Sure there is. You can for example use the conditional expressions. For example:
<span th:text="${someObject.someProperty != null} ? ${someObject.someProperty} : 'null value!'">someValue</span>
You can even omit the "else" expression:
<span th:text="${someObject.someProperty != null} ? ${someObject.someProperty}">someValue</span>
You can also take a look at the Elvis operator to display default values like this:-
<span th:text="${someObject.someProperty} ?: 'default value'">someValue</span>
The Elvis operator can be combined with the Noop token to use the template value instead. It acts like the th:text property is not set at all, when the value is not present.
<span th:text="${someObject.someProperty} ?: _">default value</span>
3 Comments
Lucky
Edit: Added the ${...} for the if condition as you have missed it. +1 for the ternary expression in th:text.
lilalinux
Could you please explain why there are multiple ${...} needed? What if I want to prefix both alternatives with e.g. 'Foo: '. Would I have to specify it twice inside the alternatives?
joninx
Your answer should be admitted as solution. Thank you.
This can also be handled using the elvis operator ?: which will add a default value when the field is null:
<span th:text="${object.property} ?: 'default value'"></span>
1 Comment
membersound
This is probably the most elegant way showing default values in thymeleaf. deserves way more upvotes!
You can use 'th:if' together with 'th:text'
<span th:if="${someObject.someProperty != null}" th:text="${someObject.someProperty}">someValue</span>
2 Comments
deFreitas
No need for
!= null only <span th:if="${someObject.someProperty}" ... is enough
Parameshwar
What about th:if for a block why its not working ?
Also worth to look at documentation for #objects build-in helper: https://www.thymeleaf.org/doc/tutorials/2.1/usingthymeleaf.html#objects
There is useful: ${#objects.nullSafe(obj, default)}
Comments
You've done twice the checking when you create
${someObject.someProperty != null} ? ${someObject.someProperty}
You should do it clean and simple as below.
<td th:text="${someObject.someProperty} ? ${someObject.someProperty} : 'null value!'"></td>
Comments
<p data-th-text ="${#strings.defaultString(yourNullable,'defaultValueIfYourValueIsNull')}"></p>
Comments
you can use this solution it is working for me
<span th:text="${#objects.nullSafe(doctor?.cabinet?.name,'')}"></span>
Comments
I use
<div th:text ="${variable != null} ? (${variable != ''} ? ${variable} : 'empty string message') : 'null message' "></div>
Comments
The shortest way! it's working for me, Where NA is my default value.
<td th:text="${ins.eValue!=null}? ${ins.eValue}:'NA'" />
Comments
The cleanest solution would be to only display it if it was set. Thymeleaf is being javascripty here:
<span th:unless="${someObject.someProperty}" th:text="${someObject.someProperty}">someValue</span>