{namespace svhs=Stratis\StratisVhs\ViewHelpers}
<v:format.trim>
    <v:variable.unset name="qGetParam"/>
    <v:variable.set name="qGetParam" value="{svhs:uri.param(get:'tx_solr')}"/>
    <f:if condition="{qGetParam}">
        <v:variable.unset name="qParam"/>
        <v:variable.set name="qParam" value="{v:variable.get(name:'qGetParam.q')}"/>{qParam}
    </f:if>
</v:format.trim>