[TASK] Remember set filter values

Classes/Controller/ListByCategoryController.php

@@ -72,6 +72,12 @@ class ListByCategoryController extends AbstractController {
 			}
 		}
 
+		// remember selection of the filter values
+		$selectedTag = $this->tagRepository->findByUid((int) $newsFilter['tag']);
+		$selectedCategory = $this->categoryRepository->findByUid((int) $newsFilter['category']);
+		$this->view->assign('selectedTag', $selectedTag);
+		$this->view->assign('selectedCategory', $selectedCategory);
+
 		if (!$filterByCategories) {
 			$categoryUids = [(int) $GLOBALS['TSFE']->id];
 		}

Resources/Private/Partials/Filter.html

@@ -2,13 +2,13 @@
 	<label for="filter-categories">
 		<f:translate key="frontend.filter.category" />
 	</label>
-	<f:form.select class="sgnews-select form-control" multiple="0" size="1" value="{selectedCategory}"
+	<f:form.select class="sgnews-select form-control" multiple="0" size="1" value="{selectedCategory.uid}"
 		property="category" optionLabelField="title" optionValueField="uid" options="{categories}"
 		id="filter-categories" prependOptionLabel="" prependOptionValue=""/>
 	<label for="filter-tags">
 		<f:translate key="frontend.filter.tag" />
 	</label>
-	<f:form.select class="sgnews-select form-control" multiple="0" size="1" value="{selectedTag}"
+	<f:form.select class="sgnews-select form-control" multiple="0" size="1" value="{selectedTag.uid}"
 		property="tag" optionValueField="uid" options="{tags}" id="filter-tags"
 		optionLabelField="title" prependOptionLabel="" prependOptionValue=""/>
 </f:form>