Non meta-property attributes of DTO entity are erased when the entity…

… is opened in standard editor #131

core/src/main/java/io/jmix/core/CopyingSystemState.java

@@ -0,0 +1,36 @@
+/*
+ * Copyright 2021 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;
+
+/**
+ * Interface to be implemented by entities having a state which is not reflected in metadata. It's usually
+ * a non-persistent state which resides in fields with types not supported by metadata, like {@code Object}.
+ * <p>
+ * Some framework mechanisms copy entity instances by copying the state of all properties known to metadata (let's
+ * call it "main" state). If you want the "system" state to be copied along with the main state, implement this
+ * interface and copy the state in the {@link #copyFrom(Object)} method.
+ *
+ * @param <T> entity type
+ */
+public interface CopyingSystemState<T> {
+
+    /**
+     * Invoked by the framework when copying the entity instance.
+     * @param source source entity
+     */
+    void copyFrom(T source);
+}

core/src/main/java/io/jmix/core/EntitySystemStateSupport.java

@@ -25,12 +25,20 @@
 @Component("core_EntitySystemStateSupport")
 public class EntitySystemStateSupport {
 
+    @SuppressWarnings({"unchecked", "rawtypes"})
     public void copySystemState(Entity src, Entity dst) {
         dst.__getEntityEntry().copy(src.__getEntityEntry());
+        if (dst instanceof CopyingSystemState) {
+            ((CopyingSystemState) dst).copyFrom(src);
+        }
     }
 
+    @SuppressWarnings({"unchecked", "rawtypes"})
     public void mergeSystemState(Entity src, Entity dst) {
         dst.__getEntityEntry().copy(src.__getEntityEntry());
+        if (dst instanceof CopyingSystemState) {
+            ((CopyingSystemState) dst).copyFrom(src);
+        }
     }
 
     public void mergeLazyLoadingState(Entity src, Entity dst, MetaProperty metaProperty,

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

@@ -960,6 +960,7 @@ public <T> T copy(T source) {
      * @param source source instance
      * @param dest   destination instance
      */
+    @SuppressWarnings({"rawtypes", "unchecked"})
     public void copy(Object source, Object dest) {
         checkNotNullArgument(source, "source is null");
         checkNotNullArgument(dest, "dest is null");
@@ -986,6 +987,10 @@ public void copy(Object source, Object dest) {
             }
         }
 
+        if (dest instanceof CopyingSystemState && dest.getClass().isAssignableFrom(source.getClass())) {
+            ((CopyingSystemState) dest).copyFrom(source);
+        }
+
         // todo dynamic attributes
 //        if (source instanceof BaseGenericIdEntity && dest instanceof BaseGenericIdEntity) {
 //            ((BaseGenericIdEntity) dest).setDynamicAttributes(((BaseGenericIdEntity<?>) source).getDynamicAttributes());
@@ -1076,6 +1081,7 @@ public <T> T deepCopy(T source) {
     /**
      * Copies all property values from source to destination excluding null values.
      */
+    @SuppressWarnings({"unchecked", "rawtypes"})
     public void deepCopy(Object source, Object destination, EntitiesHolder entitiesHolder) {
         EntityPreconditions.checkEntityType(source);
         EntityPreconditions.checkEntityType(destination);
@@ -1120,6 +1126,11 @@ public void deepCopy(Object source, Object destination, EntitiesHolder entitiesH
             }
         }
 
+        if (destination instanceof CopyingSystemState && destination.getClass().isAssignableFrom(source.getClass())) {
+            ((CopyingSystemState) destination).copyFrom(source);
+        }
+
+
         // todo dynamic attributes
 //        if (source instanceof BaseGenericIdEntity && destination instanceof BaseGenericIdEntity) {
 //            ((BaseGenericIdEntity) destination).setDynamicAttributes(((BaseGenericIdEntity<?>) source).getDynamicAttributes());