feat: add parentAnchor and parentAnchorList filter.

src/main/java/com/sitepark/ies/contentrepository/core/domain/entity/Anchor.java

@@ -1,8 +1,9 @@
 package com.sitepark.ies.contentrepository.core.domain.entity;
 
+
 import java.io.Serializable;
 import java.util.Objects;
-import java.util.Optional;
+import java.util.regex.Pattern;
 
 import com.fasterxml.jackson.annotation.JsonValue;
 import com.sitepark.ies.contentrepository.core.domain.exception.InvalidAnchor;
@@ -11,8 +12,14 @@ public final class Anchor implements Serializable {
 
 	private static final long serialVersionUID = 1L;
 
+	public static final String VALID_CHARS_REGEX = "[a-zA-Z0-9_.\\-]+";
+
+	private static final Pattern VALIDATOR_PATTERN = Pattern.compile(VALID_CHARS_REGEX);
+
+	private static final Pattern ONLY_NUMBERS_PATTERN = Pattern.compile("[0-9]+");
+
 	/**
-	 * Wird verwendet, um Anchor beim speichern von Einträgen zurück zu setzen.
+	 * Used to reset anchor when saving entries.
 	 */
 	public static final Anchor EMPTY = new Anchor("");
 
@@ -23,18 +30,18 @@ private Anchor(String name) {
 		this.name = name;
 	}
 
-	public static Optional<Anchor> ofString(String name) {
-		if (name == null) {
-			return Optional.empty();
-		} else {
+	public static Anchor ofString(String name) {
 
-			if (name.isBlank()) {
-				return Optional.of(EMPTY);
-			}
+		if (name == null) {
+			return null;
+		}
 
-			Anchor.validate(name);
-			return Optional.of(new Anchor(name));
+		if (name.isBlank()) {
+			return EMPTY;
 		}
+
+		Anchor.validate(name);
+		return new Anchor(name);
 	}
 
 	public String getName() {
@@ -45,12 +52,12 @@ public String getName() {
 	 * @throws InvalidAnchor
 	 */
 	private static void validate(String name) {
-		if (name == null) {
-			return;
+
+		if (ONLY_NUMBERS_PATTERN.matcher(name).matches()) {
+			throw new InvalidAnchor(name, "Anchor must not only consist of numbers");
 		}
 
-		// TODO: implement validator
-		if (name.indexOf(' ') != -1) {
+		if (!VALIDATOR_PATTERN.matcher(name).matches()) {
 			throw new InvalidAnchor(name, "Anchor contains Spaces");
 		}
 	}
@@ -60,14 +67,16 @@ public int hashCode() {
 		return this.name != null ? this.name.hashCode() : 0;
 	}
 
+
 	@Override
 	public boolean equals(Object o) {
+
 		if (!(o instanceof Anchor)) {
 			return false;
 		}
 
 		Anchor anchor = (Anchor)o;
-		return Objects.equals(anchor.name, this.name);
+		return Objects.equals(this.name, anchor.name);
 	}
 
 	@Override

src/main/java/com/sitepark/ies/contentrepository/core/domain/entity/Entity.java

@@ -153,7 +153,7 @@ public B id(long id) {
 
 		public B anchor(String anchor) {
 			assert anchor != null;
-			this.anchor = Anchor.ofString(anchor).get();
+			this.anchor = Anchor.ofString(anchor);
 			return this.self();
 		}
 

src/main/java/com/sitepark/ies/contentrepository/core/domain/entity/filter/Filter.java

@@ -31,6 +31,15 @@ public static ParentList parentList(Long... parentList) {
 		return new ParentList(parentList);
 	}
 
+	public static ParentAnchor parentAnchor(com.sitepark.ies.contentrepository.core.domain.entity.Anchor parentAnchor) {
+		return new ParentAnchor(parentAnchor);
+	}
+
+	public static ParentAnchorList parentAnchorList(
+			com.sitepark.ies.contentrepository.core.domain.entity.Anchor... parentAnchorList) {
+		return new ParentAnchorList(parentAnchorList);
+	}
+
 	public static Root root(Long root) {
 		return new Root(root);
 	}

src/main/java/com/sitepark/ies/contentrepository/core/domain/entity/filter/ParentAnchor.java

@@ -0,0 +1,19 @@
+package com.sitepark.ies.contentrepository.core.domain.entity.filter;
+
+import com.fasterxml.jackson.annotation.JsonProperty;
+
+public class ParentAnchor implements Filter {
+
+	@SuppressWarnings("PMD.AvoidFieldNameMatchingTypeName") // so that when deserializing it has the desired format
+	private final com.sitepark.ies.contentrepository.core.domain.entity.Anchor parentAnchor;
+
+	protected ParentAnchor(@JsonProperty("parentAnchor")
+			com.sitepark.ies.contentrepository.core.domain.entity.Anchor parentAnchor) {
+		assert parentAnchor != null : "parentAnchor is null";
+		this.parentAnchor = parentAnchor;
+	}
+
+	public com.sitepark.ies.contentrepository.core.domain.entity.Anchor getParentAnchor() {
+		return this.parentAnchor;
+	}
+}

src/main/java/com/sitepark/ies/contentrepository/core/domain/entity/filter/ParentAnchorList.java

@@ -0,0 +1,25 @@
+package com.sitepark.ies.contentrepository.core.domain.entity.filter;
+
+import java.util.List;
+
+import com.fasterxml.jackson.annotation.JsonProperty;
+
+import edu.umd.cs.findbugs.annotations.SuppressFBWarnings;
+
+public class ParentAnchorList implements Filter {
+
+	@SuppressWarnings("PMD.AvoidFieldNameMatchingTypeName") // so that when deserializing it has the desired format
+
+	private final List<com.sitepark.ies.contentrepository.core.domain.entity.Anchor> parentAnchorList;
+
+	protected ParentAnchorList(@JsonProperty("parentAnchorList")
+			com.sitepark.ies.contentrepository.core.domain.entity.Anchor... parentAnchorList) {
+		assert parentAnchorList != null : "parentAnchorList is null";
+		this.parentAnchorList = List.of(parentAnchorList);
+	}
+
+	@SuppressFBWarnings("EI_EXPOSE_REP")
+	public List<com.sitepark.ies.contentrepository.core.domain.entity.Anchor> getParentAnchorList() {
+		return this.parentAnchorList;
+	}
+}

src/test/java/com/sitepark/ies/contentrepository/core/domain/entity/filter/FilterTest.java

@@ -23,7 +23,7 @@ void testSerialize() throws Exception {
 		Filter filter =
 				or(
 					idList(6L),
-					anchor(com.sitepark.ies.contentrepository.core.domain.entity.Anchor.ofString("abc").get()),
+					anchor(com.sitepark.ies.contentrepository.core.domain.entity.Anchor.ofString("abc")),
 					and(
 						root(5L),
 						parent(7L),