Fluid condition with ContainsViewHelper

i use this condition in my fluid template:

<f:if condition="{settings.image.className} == 'lightbox'">
                <f:then>
                    ....do something
                </f:then>
        
        <f:else>
          <f:if condition="{settings.image.className} !== 'lightbox'">
                <f:then>
                 ....do something else
                </f:then>
         </f:if>
         </f:else>

</f:if>

It works fine but if $settings.image.className" is something like "lightbox container" instead of just "lightbox" it does not work of course. Unfortunately i do not know how write a condition that checks if $settings.image.className contains "lightbox" or not.

The only instructions i found are here: ViewHelper Reference .However i do not know how to apply that.

add this to the top of the partial/content Element

{namespace v=FluidTYPO3\Vhs\ViewHelpers}

and change the logic like this

<v:condition.string.contains haystack="{settings.image.className}" needle="lightbox">
   <f:then>
        ....do something
   </f:then>
   <f:else>
        ....do something else
   </f:else>
</v:condition.string.contains>