Merge branch '232-clear-filters-button-shows-up-after-empty-filter-submit' into 'development'

Fix "clear filter" button appearing

See merge request !217

CHANGELOG

@@ -10,6 +10,7 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 
 ### Changed
  - Unauthorized students for labs/courses now redirects to enroll pages by [@cedricwilleken](https://gitlab.ewi.tudelft.nl/cedricwilleken)
+ - "Clear filters" button won't appear after submission with no filters on Requests page by [@sjuhosova](https://gitlab.ewi.tudelft.nl/sjuhosova)
 
 ## [1.0.0] - 2019-10-24
 Initial public release
\ No newline at end of file

src/main/java/nl/tudelft/ewi/queue/service/RequestTableService.java

@@ -15,9 +15,7 @@
  */
 package nl.tudelft.ewi.queue.service;
 
-import java.util.List;
-import java.util.Map;
-import java.util.Optional;
+import java.util.*;
 import java.util.function.Function;
 import java.util.stream.Collectors;
 import java.util.stream.Stream;
@@ -38,6 +36,7 @@ import org.springframework.util.LinkedMultiValueMap;
 import org.springframework.util.MultiValueMap;
 
 import com.google.common.collect.Lists;
+import com.google.common.collect.Sets;
 import com.querydsl.core.types.Predicate;
 import com.querydsl.core.types.dsl.BooleanExpression;
 
@@ -59,6 +58,9 @@ import com.querydsl.core.types.dsl.BooleanExpression;
 public class RequestTableService {
 	private static final String PREDICATE_POSTFIX = "_filter_predicate";
 	private static final String PARAMETERS_POSTFIX = "_filter_parameters";
+	private static final Set<String> FILTERS = Sets.newHashSet(
+			"lab.course", "lab", "assignment", "room", "assistant", "status", "requestType"
+	);
 
 	@Autowired
 	private RoomRepository roomRepository;
@@ -71,8 +73,8 @@ public class RequestTableService {
 
 	/**
 	 * Analyses the given parameters and performs an action based on it. If the parameters contain a 'clear'
-	 * attribute, the filters stored in the current session are removed. Otherwise, the given parameters and
-	 * predicate are stored in the current session.
+	 * attribute, the filters stored in the current session are removed. If the parameters do not contain a filtering
+	 * attribute, nothing is submitted. Otherwise, the given parameters and predicate are stored in the current session.
 	 *
 	 * @param request    The HttpServletRequest used to get the session.
 	 * @param parameters The parameters to store.
@@ -81,10 +83,8 @@ public class RequestTableService {
 	public void submitFilters(HttpServletRequest request,
 			MultiValueMap<String, String> parameters,
 			Predicate predicate) {
-		if (parameters == null) {
-			return;
-		}
 
+		if (containsFilterParams(parameters)) {
 			String key = pathFromRequest(request);
 			if (parameters.containsKey("clear")) {
 				clearFilters(request, key);
@@ -92,6 +92,7 @@ public class RequestTableService {
 				storeFilters(request, key, parameters, predicate);
 			}
 		}
+	}
 
 	/**
 	 * Stores the given parameters and predicates under the given key in the current session.
@@ -267,6 +268,15 @@ public class RequestTableService {
 				.orElse(new LinkedMultiValueMap<>());
 	}
 
+	/**
+	 * Checks whether the query parameters include filters.
+	 * @param parameters the query parameters of the request
+	 * @return true if there is at least one filtering query parameter
+	 */
+	private boolean containsFilterParams(MultiValueMap<String, String> parameters) {
+		return parameters != null && !(Sets.intersection(FILTERS, parameters.keySet())).isEmpty();
+	}
+
 	/**
 	 * Flatmaps a list of courses to a list of labs.
 	 *