Support for ElementCollection and transient collections

jmix-appsettings/appsettings-flowui/src/main/java/io/jmix/appsettingsflowui/componentfactory/AppSettingsComponentGenerationStrategy.java

@@ -34,16 +34,20 @@
 import io.jmix.flowui.UiComponents;
 import io.jmix.flowui.action.entitypicker.EntityClearAction;
 import io.jmix.flowui.action.entitypicker.EntityLookupAction;
+import io.jmix.flowui.action.multivaluepicker.MultiValueSelectAction;
+import io.jmix.flowui.action.valuepicker.ValueClearAction;
 import io.jmix.flowui.component.ComponentGenerationContext;
 import io.jmix.flowui.component.factory.AbstractComponentGenerationStrategy;
 import io.jmix.flowui.component.factory.EntityFieldCreationSupport;
 import io.jmix.flowui.component.select.JmixSelect;
 import io.jmix.flowui.component.textfield.JmixPasswordField;
 import io.jmix.flowui.component.textfield.TypedTextField;
 import io.jmix.flowui.component.valuepicker.EntityPicker;
+import io.jmix.flowui.component.valuepicker.JmixMultiValuePicker;
 import io.jmix.flowui.data.SupportsValueSource;
 import io.jmix.flowui.data.ValueSource;
 import io.jmix.flowui.data.value.ContainerValueSource;
+import io.jmix.flowui.kit.action.Action;
 import io.jmix.flowui.kit.component.ComponentUtils;
 import org.springframework.core.Ordered;
 import org.springframework.lang.Nullable;
@@ -84,19 +88,19 @@ public Component createComponent(ComponentGenerationContext context) {
                 }
             }
 
-            if (isBoolean(metaProperty)) {
+            if (metadataTools.isElementCollection(metaProperty)) {
+                field = createMultiValuePickerField();
+
+            } else if (isBoolean(metaProperty)) {
                 field = createBooleanField();
-            }
 
-            if (isSecret(metaProperty)) {
+            } else if (isSecret(metaProperty)) {
                 field = createPasswordField();
-            }
 
-            if (range.isEnum()) {
+            } else if (range.isEnum()) {
                 field = createEnumField(range);
-            }
 
-            if (range.isClass()) {
+            } else if (range.isClass()) {
                 field = createEntityPickerField();
             }
 
@@ -109,6 +113,13 @@ public Component createComponent(ComponentGenerationContext context) {
         return null;
     }
 
+    protected JmixMultiValuePicker<?> createMultiValuePickerField() {
+        JmixMultiValuePicker<?> valuePicker = uiComponents.create(JmixMultiValuePicker.class);
+        valuePicker.addAction(actions.create(MultiValueSelectAction.ID));
+        valuePicker.addAction(actions.create(ValueClearAction.ID));
+        return valuePicker;
+    }
+
     @SuppressWarnings({"rawtypes", "unchecked"})
     protected Select<?> createEnumField(Range range) {
         JmixSelect enumField = uiComponents.create(JmixSelect.class);
@@ -154,7 +165,7 @@ protected boolean isBoolean(MetaProperty metaProperty) {
     }
 
     protected boolean requireTextArea(MetaProperty metaProperty, @Nullable Object item) {
-        if (!String.class.equals(metaProperty.getJavaType())) {
+        if (!String.class.equals(metaProperty.getJavaType()) || metadataTools.isElementCollection(metaProperty)) {
             return false;
         }
 

jmix-appsettings/appsettings-flowui/src/main/java/io/jmix/appsettingsflowui/view/appsettings/AppSettingsEntityView.java

@@ -55,6 +55,7 @@
 import io.jmix.flowui.util.UnknownOperationResult;
 import io.jmix.flowui.view.*;
 import io.jmix.flowui.view.navigation.RouteSupport;
+import org.jspecify.annotations.NonNull;
 import org.springframework.beans.factory.annotation.Autowired;
 
 import jakarta.persistence.Convert;
@@ -412,7 +413,7 @@ protected InstanceContainer initInstanceContainerWithDbEntity() {
         InstanceContainer container = dataComponents.createInstanceContainer(currentMetaClass.getJavaClass());
         entityToEdit = dataManager.load(currentMetaClass.getJavaClass())
                 .query(String.format(SELECT_APP_SETTINGS_ENTITY_QUERY, currentMetaClass.getName()))
-                .fetchPlan(fetchPlans.builder(currentMetaClass.getJavaClass()).addFetchPlan(FetchPlan.LOCAL).build())
+                .fetchPlan(createFetchPlan())
                 .hint(PersistenceHints.SOFT_DELETION, false)
                 .optional()
                 .orElse(null);
@@ -424,6 +425,16 @@ protected InstanceContainer initInstanceContainerWithDbEntity() {
         return container;
     }
 
+    protected FetchPlan createFetchPlan() {
+        FetchPlanBuilder builder = fetchPlans.builder(currentMetaClass.getJavaClass()).addFetchPlan(FetchPlan.LOCAL);
+        for (MetaProperty property : currentMetaClass.getProperties()) {
+            if (metadataTools.isElementCollection(property)) {
+                builder.add(property.getName());
+            }
+        }
+        return builder.build();
+    }
+
     protected boolean isApplicationSettingsEntity(MetaClass metaClass) {
         return AppSettingsEntity.class.isAssignableFrom(metaClass.getJavaClass());
     }

jmix-appsettings/appsettings/src/main/java/io/jmix/appsettings/impl/AppSettingsToolsImpl.java

@@ -46,11 +46,15 @@ public class AppSettingsToolsImpl implements AppSettingsTools {
     @Autowired
     protected AppSettingsProperties appSettingsProperties;
 
+    @Autowired
+    protected FetchPlans fetchPlans;
+
     @Override
     public <T extends AppSettingsEntity> T loadAppSettingsEntityFromDataStore(Class<T> clazz) {
         //only one record for T can exist at the same time in database with default identifier
         return getDataManagerForAppSettingsEntity().load(clazz)
                 .id(Id.of(1, clazz))
+                .fetchPlan(createFetchPlan(clazz))
                 .optional().orElse(metadata.create(clazz, 1));
     }
 
@@ -114,6 +118,18 @@ protected UnconstrainedDataManager getDataManagerForAppSettingsEntity() {
         return appSettingsProperties.isCheckPermissionsForAppSettingsEntity() ? dataManager : unconstrainedDataManager;
     }
 
+    protected FetchPlan createFetchPlan(Class<?> clazz) {
+        FetchPlanBuilder builder = fetchPlans.builder(clazz).addFetchPlan(FetchPlan.LOCAL);
+        for (MetaProperty property : metadata.getClass(clazz).getProperties()) {
+            if (property.getRange().isClass()) {
+                builder.add(property.getName(), FetchPlan.BASE);
+            } else if (metadataTools.isElementCollection(property)) {
+                builder.add(property.getName());
+            }
+        }
+        return builder.build();
+    }
+
     @Override
     public <T extends AppSettingsEntity> List<String> getPropertyNames(Class<T> clazz) {
         return metadata.getClass(clazz).getProperties().stream()

jmix-core/core/core.gradle

@@ -65,6 +65,7 @@ dependencies {
     testImplementation 'org.springframework:spring-test'
     testImplementation "org.spockframework:spock-core"
     testImplementation "org.spockframework:spock-spring"
+    testImplementation 'org.assertj:assertj-core'
     testRuntimeOnly 'org.junit.jupiter:junit-jupiter-engine'
     testRuntimeOnly 'org.junit.platform:junit-platform-launcher'
     testRuntimeOnly 'org.junit.vintage:junit-vintage-engine'

jmix-core/core/src/main/java/io/jmix/core/MetadataTools.java

@@ -487,6 +487,15 @@ public boolean isSecret(MetaProperty metaProperty) {
         return Boolean.TRUE.equals(metaProperty.getAnnotatedElement().isAnnotationPresent(Secret.class));
     }
 
+    /**
+     * Determine whether the given property is an element collection.
+     * An element collection is a collection of simple types, such as strings, numbers, or dates.
+     * In a JPA entity, an element collection attribute is annotated with {@code @ElementCollection}.
+     */
+    public boolean isElementCollection(MetaProperty metaProperty) {
+        return metaProperty.getRange().isDatatype() && metaProperty.getRange().getCardinality().isMany();
+    }
+
     public Map<String, Object> getMetaAnnotationAttributes(Map<String, Object> metaAnnotations, Class<?> metaAnnotationClass) {
         @SuppressWarnings("unchecked")
         Map<String, Object> map = (Map<String, Object>) metaAnnotations.get(metaAnnotationClass.getName());

jmix-core/core/src/main/java/io/jmix/core/impl/EntityElementCollectionInitializer.java

@@ -0,0 +1,69 @@
+/*
+ * Copyright 2025 Haulmont.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package io.jmix.core.impl;
+
+import io.jmix.core.EntityInitializer;
+import io.jmix.core.JmixOrder;
+import io.jmix.core.Metadata;
+import io.jmix.core.MetadataTools;
+import io.jmix.core.entity.EntityValues;
+import io.jmix.core.metamodel.model.MetaClass;
+import io.jmix.core.metamodel.model.MetaProperty;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+import org.springframework.beans.factory.annotation.Autowired;
+import org.springframework.core.Ordered;
+import org.springframework.stereotype.Component;
+
+import java.util.ArrayList;
+import java.util.HashSet;
+import java.util.List;
+import java.util.Set;
+
+@Component("core_EntityElementCollectionInitializer")
+public class EntityElementCollectionInitializer implements EntityInitializer, Ordered {
+
+    private static final Logger log = LoggerFactory.getLogger(EntityElementCollectionInitializer.class);
+
+    @Autowired
+    private Metadata metadata;
+
+    @Autowired
+    private MetadataTools metadataTools;
+
+    @Override
+    public void initEntity(Object entity) {
+        MetaClass metaClass = metadata.getClass(entity);
+        for (MetaProperty property : metaClass.getProperties()) {
+            if (metadataTools.isElementCollection(property)) {
+                if (List.class.isAssignableFrom(property.getJavaType())) {
+                    EntityValues.setValue(entity, property.getName(), new ArrayList<>());
+                } else if (Set.class.isAssignableFrom(property.getJavaType())) {
+                    EntityValues.setValue(entity, property.getName(), new HashSet<>());
+                } else {
+                    log.warn("Unsupported element collection type {} of property {}.{}",
+                            property.getJavaType(), metaClass.getName(), property.getName());
+                }
+            }
+        }
+    }
+
+    @Override
+    public int getOrder() {
+        return JmixOrder.HIGHEST_PRECEDENCE + 25;
+    }
+}

jmix-core/core/src/main/java/io/jmix/core/impl/FetchPlanRepositoryImpl.java

@@ -286,7 +286,9 @@ protected FetchPlan createKeyValueFetchPlan(KeyValueMetaClass metaClass, String
 
     protected void addAttributesToLocalFetchPlan(MetaClass metaClass, FetchPlanBuilder fetchPlanBuilder) {
         for (MetaProperty property : metaClass.getProperties()) {
-            if (!property.getRange().isClass() && isPersistent(metaClass, property)) {
+            if (isPersistent(metaClass, property)
+                    && !property.getRange().isClass()
+                    && !property.getRange().getCardinality().isMany()) {
                 fetchPlanBuilder.add(property.getName());
             }
         }
@@ -311,7 +313,7 @@ protected void addAttributesToBaseFetchPlan(MetaClass metaClass,
                                                 Set<FetchPlanLoader.FetchPlanInfo> visited) {
         for (MetaProperty metaProperty : metaClass.getProperties()) {
             if (isPersistent(metaClass, metaProperty)) {
-                if (!metaProperty.getRange().isClass()) {
+                if (!metaProperty.getRange().isClass() && !metaProperty.getRange().getCardinality().isMany()) {
                     fetchPlanBuilder.add(metaProperty.getName());
                 } else if (metaProperty.getType() == MetaProperty.Type.EMBEDDED) {
                     addClassAttributeWithFetchPlan(metaProperty, FetchPlan.BASE, fetchPlanBuilder, info, visited);

jmix-core/core/src/main/java/io/jmix/core/impl/MetaModelLoader.java

@@ -675,7 +675,10 @@ protected boolean isMandatory(AccessibleObject base) {
 
     protected Range.Cardinality getCardinality(Field field) {
         if (field.isAnnotationPresent(Column.class)) {
-            return Range.Cardinality.NONE;
+            if (field.isAnnotationPresent(ElementCollection.class))
+                return Range.Cardinality.ONE_TO_MANY;
+            else
+                return Range.Cardinality.NONE;
         } else if (field.isAnnotationPresent(OneToOne.class)) {
             return Range.Cardinality.ONE_TO_ONE;
         } else if (field.isAnnotationPresent(OneToMany.class)) {
@@ -740,7 +743,8 @@ protected boolean hasJpaAnnotation(AnnotatedElement annotatedElement) {
                 || annotatedElement.isAnnotationPresent(ManyToMany.class)
                 || annotatedElement.isAnnotationPresent(OneToOne.class)
                 || annotatedElement.isAnnotationPresent(Embedded.class)
-                || annotatedElement.isAnnotationPresent(EmbeddedId.class);
+                || annotatedElement.isAnnotationPresent(EmbeddedId.class)
+                || annotatedElement.isAnnotationPresent(ElementCollection.class);
     }
 
     protected boolean hasJpaAnnotation(Class<?> javaClass) {

jmix-core/core/src/test/java/element_collection/ElementCollectionTest.java

@@ -0,0 +1,81 @@
+/*
+ * Copyright 2025 Haulmont.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package element_collection;
+
+import io.jmix.core.CoreConfiguration;
+import io.jmix.core.Metadata;
+import io.jmix.core.MetadataTools;
+import io.jmix.core.metamodel.model.MetaClass;
+import io.jmix.core.metamodel.model.MetaProperty;
+import io.jmix.core.metamodel.model.Range;
+import org.junit.jupiter.api.Test;
+import org.junit.jupiter.api.extension.ExtendWith;
+import org.springframework.beans.factory.annotation.Autowired;
+import org.springframework.test.context.ContextConfiguration;
+import org.springframework.test.context.junit.jupiter.SpringExtension;
+import test_support.addon1.TestAddon1Configuration;
+import test_support.app.TestAppConfiguration;
+import test_support.app.entity.element_collection.EcAlpha;
+
+import java.util.List;
+import java.util.Set;
+
+import static org.assertj.core.api.Assertions.assertThat;
+
+@ExtendWith(SpringExtension.class)
+@ContextConfiguration(classes = {CoreConfiguration.class, TestAddon1Configuration.class, TestAppConfiguration.class})
+public class ElementCollectionTest {
+
+    @Autowired
+    Metadata metadata;
+    @Autowired
+    MetadataTools metadataTools;
+
+    @Test
+    void testMetadata() {
+        MetaClass metaClass = metadata.getClass(EcAlpha.class);
+
+        MetaProperty property = metaClass.findProperty("tags");
+        assertThat(property).isNotNull();
+
+        MetaProperty.Type propertyType = property.getType();
+        assertThat(propertyType).isEqualTo(MetaProperty.Type.DATATYPE);
+
+        Range propertyRange = property.getRange();
+        assertThat(propertyRange.isDatatype()).isTrue();
+
+        Range.Cardinality cardinality = propertyRange.getCardinality();
+        assertThat(cardinality.isMany()).isTrue();
+
+        assertThat(propertyRange.isOrdered()).isTrue();
+
+        assertThat(metadataTools.isJpa(property)).isTrue();
+    }
+
+    @Test
+    void testInitialization() {
+        EcAlpha alpha = metadata.create(EcAlpha.class);
+
+        assertThat(alpha.getTags()).isNotNull();
+        assertThat(alpha.getTags()).isInstanceOf(List.class);
+        assertThat(alpha.getTags()).isEmpty();
+
+        assertThat(alpha.getNumbers()).isNotNull();
+        assertThat(alpha.getNumbers()).isInstanceOf(Set.class);
+        assertThat(alpha.getNumbers()).isEmpty();
+    }
+}