OZG-4109 filter out postkorbId placeholder

src/main/java/de/ozgcloud/formcycle/formdata/PluginFormDataAdapter.java

@@ -23,6 +23,7 @@
 package de.ozgcloud.formcycle.formdata;
 
 import static java.util.Objects.*;
+import static org.apache.commons.lang3.StringUtils.*;
 
 import java.util.ArrayList;
 import java.util.Arrays;
@@ -33,7 +34,9 @@ import java.util.Objects;
 import java.util.Optional;
 import java.util.Set;
 import java.util.function.Predicate;
+import java.util.regex.Pattern;
 import java.util.stream.Collectors;
+import java.util.stream.Stream;
 
 import de.xima.fc.interfaces.form.IFormDataAdapter;
 import de.xima.fc.interfaces.workflow.execution.IWorkflowExecutionEnvironmentData;
@@ -43,6 +46,8 @@ import lombok.RequiredArgsConstructor;
 
 @RequiredArgsConstructor
 public class PluginFormDataAdapter {
+
+	private static final Pattern FORMCYCLE_PLACEHOLDER = Pattern.compile("^\\[%\\s*\\$.+%]$");
 	private static final boolean AS_FIELD_NAME = false;
 	private static final String TEXT_KEY = "text";
 	static final String POSTKORB_FORM_KEY = "PostboxId";
@@ -137,7 +142,15 @@ public class PluginFormDataAdapter {
 
 	Optional<String> getPostkorbId() {
 		return Optional.ofNullable(getFormDataAdapter().getFieldValues(POSTKORB_FORM_KEY))
-				.flatMap(list -> list.stream().flatMap(Arrays::stream).findFirst());
+				.flatMap(this::extractPostkorbId);
+	}
+
+	Optional<String> extractPostkorbId(List<String[]> values) {
+		return values.stream().flatMap(Stream::of).filter(this::isValidPostkorbId).findFirst();
+	}
+
+	boolean isValidPostkorbId(String postkorbId) {
+		return isNotBlank(postkorbId) && !FORMCYCLE_PLACEHOLDER.matcher(postkorbId).matches();
 	}
 
 	private String getFormName() {

src/test/java/de/ozgcloud/formcycle/formdata/PluginFormDataAdapterTest.java

@@ -42,6 +42,9 @@ import org.junit.jupiter.api.BeforeEach;
 import org.junit.jupiter.api.DisplayName;
 import org.junit.jupiter.api.Nested;
 import org.junit.jupiter.api.Test;
+import org.junit.jupiter.params.ParameterizedTest;
+import org.junit.jupiter.params.provider.NullSource;
+import org.junit.jupiter.params.provider.ValueSource;
 import org.mockito.InjectMocks;
 import org.mockito.Mock;
 import org.mockito.Spy;
@@ -440,6 +443,21 @@ class PluginFormDataAdapterTest {
 
 			assertThat(postkorbId).isEmpty();
 		}
+
+	}
+
+	@Nested
+	class TestPostkorbIdValidation {
+
+		@DisplayName("should return FALSE when")
+		@ParameterizedTest(name = "postkorbId is \"{0}\"")
+		@NullSource
+		@ValueSource(strings = {"", "[%$id%]", "[% $id%]", "[%$id %]", "[% $id %]"})
+		void shouldFilterOutEmptyValues(String postkorbId) {
+			var isValid = adapter.isValidPostkorbId(postkorbId);
+
+			assertThat(isValid).isFalse();
+		}
 	}
 
 	@Nested