public function updateSearchForm(Form $form)
    {
        /** @var DropdownField $filterField */
        $filterField = $form->Fields()->fieldByName('Search__FilterClass');
        if ($filterField) {
            $filterField->setEmptyString('')->setHasEmptyDefault(false);
        }
    }
public function updateSearchForm(Form $form)
    {
        /** @var DropdownField $filterField */
        $filterField = $form->Fields()->fieldByName('Search__FilterClass');
        if ($filterField) {
            $filterField->setEmptyString('')->setHasEmptyDefault(false);
        }
    }
public function updateSearchForm ( Form $ form ) { /** @var DropdownField $filterField */ $ filterField = $ form -> Fields ( ) -> fieldByName ( 'Search__FilterClass' ) ; if ( $ filterField ) { $ filterField -> setEmptyString ( '' ) -> setHasEmptyDefault ( false ) ; } }
Remove the empty default string on the class filter, which adds "All pages" again. This is already
added by ElementSiteTreeFilterSearch.

@param Form $form
Remove the empty default string on the class filter which adds All pages again . This is already added by ElementSiteTreeFilterSearch .