CcmNG: Custom JSON converters for ComponentModels

git-svn-id: https://svn.libreccm.org/ccm/ccm_ng@5663 8810af33-2d31-482b-a856-94f89814c4df

ccm-cms/src/main/java/org/librecms/pagemodel/CategorizedItemComponentJsonBuilder.java

@@ -50,7 +50,7 @@ public class CategorizedItemComponentJsonBuilder
         }
 
         final CategorizedItemComponent component
-                                       = (CategorizedItemComponent) componentModel;
+                                           = (CategorizedItemComponent) componentModel;
 
         convertBasePropertiesToJson(component, objectBuilder);
         convertContentItemComponentPropertiesToJson(component, objectBuilder);
@@ -59,16 +59,21 @@ public class CategorizedItemComponentJsonBuilder
     }
 
     @Override
-    public ComponentModel fromJson(final JsonObject jsonObject) {
+    public void fromJson(final JsonObject jsonObject,
+                         final ComponentModel componentModel) {
 
         Objects.requireNonNull(jsonObject);
 
-        final CategorizedItemComponent component = new CategorizedItemComponent();
+        if (!(componentModel instanceof CategorizedItemComponent)) {
+            throw new IllegalArgumentException(
+                "This converter only processes CategorizedItemComponents.");
+        }
+
+        final CategorizedItemComponent component
+                                       = (CategorizedItemComponent) componentModel;
 
         readBasePropertiesFromJson(jsonObject, component);
         readContentItemComponentPropertiesFromJson(jsonObject, component);
-        
-        return component;
     }
 
 }

ccm-cms/src/main/java/org/librecms/pagemodel/CategoryTreeComponentJsonConverter.java

@@ -61,21 +61,30 @@ public class CategoryTreeComponentJsonConverter
         return builder.build();
     }
 
-
     @Override
-    public ComponentModel fromJson(final JsonObject jsonObject) {
+    public void fromJson(final JsonObject jsonObject,
+                         final ComponentModel componentModel) {
 
         Objects.requireNonNull(jsonObject);
 
-        final CategoryTreeComponent categoryTree = new CategoryTreeComponent();
+        if (!(componentModel instanceof CategoryTreeComponent)) {
+            throw new IllegalArgumentException(
+                "This converter only processes CategoryTreeComponents.");
+        }
+
+        final CategoryTreeComponent categoryTree
+                                    = (CategoryTreeComponent) componentModel;
+
+        if (!(componentModel instanceof CategoryTreeComponent)) {
+            throw new IllegalArgumentException(
+                "This converter only processes CategoryTreeComponents.");
+        }
 
         readBasePropertiesFromJson(jsonObject, categoryTree);
 
         if (!jsonObject.isNull(SHOW_FULL_TREE)) {
             categoryTree.setShowFullTree(jsonObject.getBoolean(SHOW_FULL_TREE));
         }
-        
-        return categoryTree;
     }
 
 }

ccm-cms/src/main/java/org/librecms/pagemodel/FixedContentItemComponentJsonConverter.java

@@ -72,12 +72,18 @@ public class FixedContentItemComponentJsonConverter
     }
 
     @Override
-    public ComponentModel fromJson(final JsonObject jsonObject) {
+    public void fromJson(final JsonObject jsonObject,
+                         final ComponentModel componentModel) {
 
         Objects.requireNonNull(jsonObject);
 
+        if (!(componentModel instanceof FixedContentItemComponent)) {
+            throw new IllegalArgumentException(
+                "This converter only processes FixedContentItemComponents.");
+        }
+
         final FixedContentItemComponent component
-                                            = new FixedContentItemComponent();
+                                        = (FixedContentItemComponent) componentModel;
 
         readBasePropertiesFromJson(jsonObject, component);
         readContentItemComponentPropertiesFromJson(jsonObject, component);
@@ -90,12 +96,9 @@ public class FixedContentItemComponentJsonConverter
                 .setContentItem(itemRepo
                     .findByUuid(uuid)
                     .orElseThrow(() -> new UnexpectedErrorException(
-                        String.format("No ContentItem with UUID \"%s\" exists.",
+                    String.format("No ContentItem with UUID \"%s\" exists.",
-                                      uuid))));
+                                  uuid))));
-            
         }
-        
-        return component;
     }
 
 }

ccm-cms/src/main/java/org/librecms/pagemodel/GreetingItemComponentJsonConverter.java

@@ -48,7 +48,7 @@ public class GreetingItemComponentJsonConverter
         }
 
         final GreetingItemComponent component
-                                    = (GreetingItemComponent) componentModel;
+                                        = (GreetingItemComponent) componentModel;
 
         final JsonObjectBuilder objectBuilder = Json.createObjectBuilder();
 
@@ -59,16 +59,21 @@ public class GreetingItemComponentJsonConverter
     }
 
     @Override
-    public ComponentModel fromJson(final JsonObject jsonObject) {
+    public void fromJson(final JsonObject jsonObject,
+                         final ComponentModel componentModel) {
 
         Objects.requireNonNull(jsonObject);
 
-        final GreetingItemComponent component = new GreetingItemComponent();
+        if (!(componentModel instanceof GreetingItemComponent)) {
+            throw new IllegalArgumentException(
+                "This converter only processes GreetingItemComponents.");
+        }
+
+        final GreetingItemComponent component
+                                        = (GreetingItemComponent) componentModel;
 
         readBasePropertiesFromJson(jsonObject, component);
         readContentItemComponentPropertiesFromJson(jsonObject, component);
-        
-        return component;
     }
 
 }

ccm-cms/src/main/java/org/librecms/pagemodel/ItemListComponentJsonConverter.java

@@ -78,11 +78,17 @@ public class ItemListComponentJsonConverter
     }
 
     @Override
-    public ComponentModel fromJson(final JsonObject jsonObject) {
+    public void fromJson(final JsonObject jsonObject,
+                   final ComponentModel componentModel) {
 
         Objects.requireNonNull(jsonObject);
         
-        final ItemListComponent itemList = new ItemListComponent();
+        if (!(componentModel instanceof ItemListComponent)) {
+            throw new IllegalArgumentException(
+                "This implementation does only handle ItemListComponents.");
+        }
+
+        final ItemListComponent itemList = (ItemListComponent) componentModel;
         readBasePropertiesFromJson(jsonObject, itemList);
 
         if (!jsonObject.isNull(DESCENDING)) {
@@ -107,8 +113,6 @@ public class ItemListComponentJsonConverter
             .collect(Collectors.toList()));
             
         }
-
-        return itemList;
     }
 
 }

ccm-core/src/main/java/org/libreccm/pagemodel/ComponentModelJsonConverter.java

@@ -31,16 +31,19 @@ public interface ComponentModelJsonConverter {
      * Convert a {@link ComponentModel} to JSON.
      *
      * @param componentModel The {@link ComponentModel} to convert.
+     *
      * @return The JSON representation of the provided {@link ComponentModel}.
      */
     JsonObject toJson(ComponentModel componentModel);
 
     /**
-     * Read the values of a {@link ComponentModel} from a JSON object.
+     * Read the values of a {@link ComponentModel} from a JSON object and set
+     * them on the provided component model.
      *
-     * @param jsonObject The JSON object with the values.
+     * @param jsonObject     The JSON object with the values.
-     * @return The {@link ComponentModel}.
+     * @param componentModel The {@link ComponentModel} on which the values are
+     *                       set.
      */
-    ComponentModel fromJson(JsonObject jsonObject);
+    void fromJson(JsonObject jsonObject, ComponentModel componentModel);
 
 }