Fluid - condition to check if value is NULL not working

Question

I try to output my element only if the value of the property fileEn is NULL (fileEn => NULL)

<f:if condition="{file.fileEn}==NULL">
    <f:debug title='file'>{file}</f:debug>
</f:if>

However this is also showing me elements where fileEn is not NULL!

Black · Accepted Answer · 2019-10-17T08:18:47.423

10

You can't check if something is NULL like this, it works like this:

Render only if property is NULL:

<f:if condition="{file.fileEn}">
    <f:then>

    </f:then>
    <f:else>
        <!-- Property is NULL -->
        <f:debug title='file'>{file}</f:debug>
    </f:else>
</f:if>

Render only if property is NOT NULL:

<f:if condition="{file.fileEn}">
    <!-- Property is not NULL -->
    <f:debug title='file'>{file}</f:debug>
</f:if>

edited Oct 17 '19 at 08:18

answered Jan 25 '17 at 12:41

Black

18,150
39
158
271

This is not correct, in your case, the property could also be "" (empty string) or FALSE, besides NULL. – Sven Oct 31 '22 at 15:23

score 1 · Answer 2 · edited Dec 21 '21 at 11:04

1

<f:if condition="{0:myVariable} == {0: NULL}'"></f:if>

Should also work

edited Dec 21 '21 at 11:04

Black

18,150
39
158
271

answered Dec 21 '21 at 10:54

Stanislav Seifert

11
1

I can't verify, I don't work with fluid anymore (thx god), but thx for your contribution. – Black Dec 21 '21 at 11:04
It works, but I am curious: why? – qba-dev Jan 25 '23 at 17:01

score 1 · Answer 3 · answered Mar 24 '22 at 10:14

Don't use the f:if ViewHelper to test on NULL: using it, a falsy but not NULL value would incorrectly be considered NULL, e.g. when file.fileEn = "0".

Instead use the IsNullViewHelper:

<html
  xmlns:f="http://typo3.org/ns/TYPO3/CMS/Fluid/ViewHelpers"
  xmlns:v="http://typo3.org/ns/FluidTYPO3/Vhs/ViewHelpers"
  data-namespace-typo3-fluid="true"
>

  <v:condition.variable.isNull value="{file.fileEn}">
    <f:then>
      is NULL
    </f:then>
    <f:else>
      is not NULL
    </f:else>
  </v:condition.variable.isNull>

</html>

score 0 · Answer 4 · answered Sep 03 '21 at 18:59

0

Alternatively you can do this:

<f:if condition="{file.fileEn}==">
    <f:debug title='file'>{file}</f:debug>
</f:if>

answered Sep 03 '21 at 18:59

Andreas B

377
3
10

score 0 · Answer 5 · answered Jun 28 '23 at 08:22

0

<v:condition.variable.isNull value="{newsItem.starttime}">

If I put something like this, the isNullViewHelper interprets this as a string, rather than as a variable...

answered Jun 28 '23 at 08:22

Darko Antunovic

1
1

Fluid - condition to check if value is NULL not working

5 Answers5