[29] Add the ability to order features during the serialization

Bug: #29
eclipse-sirius · Jan 11, 2024 · 8be6444 · 8be6444
1 parent e11bdfd
commit 8be6444
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diff --git a/...clipse.sirius.emfjson/src/main/java/org/eclipse/sirius/emfjson/resource/JsonResource.java b/...clipse.sirius.emfjson/src/main/java/org/eclipse/sirius/emfjson/resource/JsonResource.java
@@ -16,6 +16,7 @@
 
 import java.io.InputStream;
 import java.io.OutputStream;
+import java.util.Comparator;
 import java.util.Map;
 
 import org.eclipse.emf.common.util.URI;
@@ -418,6 +419,12 @@ interface IEObjectHandler {
      */
     String OPTION_ID_MANAGER = "OPTION_ID_MANAGER"; //$NON-NLS-1$
 
+    /**
+     * An option to provide a {@link Comparator} of {@link EStructuralFeature} to determine the order of the attributes
+     * in the serialized Json.
+     */
+    Object OPTION_SAVE_FEATURES_ORDER_COMPARATOR = "OPTION_SAVE_FEATURES_ORDER_COMPARATOR"; //$NON-NLS-1$
+
     /**
      * Associate an ID to the {@link EObject}.
      *

diff --git a/....sirius.emfjson/src/main/java/org/eclipse/sirius/emfjson/utils/GsonEObjectSerializer.java b/....sirius.emfjson/src/main/java/org/eclipse/sirius/emfjson/utils/GsonEObjectSerializer.java
@@ -24,12 +24,14 @@
 import java.text.SimpleDateFormat;
 import java.util.Collection;
 import java.util.Collections;
+import java.util.Comparator;
 import java.util.Date;
 import java.util.Iterator;
 import java.util.LinkedHashMap;
 import java.util.List;
 import java.util.Map;
 import java.util.Map.Entry;
+import java.util.stream.Collectors;
 
 import org.eclipse.emf.common.util.EList;
 import org.eclipse.emf.common.util.EMap;
@@ -871,10 +873,18 @@ private JsonElement createJsonHeader() {
      *            The EObject to serialize
      * @return A JsonObject containing all the properties of the given object
      */
+    @SuppressWarnings("unchecked")
     private JsonObject serializeEAllStructuralFeatures(EObject eObject) {
         JsonObject properties = new JsonObject();
         EClass eClass = eObject.eClass();
-        EList<EStructuralFeature> eAllStructuralFeatures = eClass.getEAllStructuralFeatures();
+        List<EStructuralFeature> eAllStructuralFeatures = eClass.getEAllStructuralFeatures();
+
+        Object orderFeatures = this.options.get(JsonResource.OPTION_SAVE_FEATURES_ORDER_COMPARATOR);
+        if (orderFeatures instanceof Comparator<?>) {
+            eAllStructuralFeatures = eAllStructuralFeatures.stream() //
+                    .sorted((Comparator<? super EStructuralFeature>) orderFeatures) //
+                    .collect(Collectors.toList());
+        }
 
         for (EStructuralFeature eStructuralFeature : eAllStructuralFeatures) {
             if (this.shouldSerialize(eObject, eStructuralFeature)) {

diff --git a/.../main/java/org/eclipse/sirius/emfjson/tests/internal/unit/save/SerializeOptionsTests.java b/.../main/java/org/eclipse/sirius/emfjson/tests/internal/unit/save/SerializeOptionsTests.java
@@ -25,6 +25,7 @@
 import java.nio.charset.Charset;
 import java.util.ArrayList;
 import java.util.Collections;
+import java.util.Comparator;
 import java.util.Map;
 
 import org.eclipse.emf.common.util.BasicEList;
@@ -450,4 +451,23 @@ public void postLoad(JsonResource resource, InputStream inputStream, Map<?, ?> l
         this.testSave("SimpleModelWithOnlyDefaultValueForResourceHandlerPreSavingTest.xmi"); //$NON-NLS-1$
 
     }
+
+    /**
+     * Test the serialization with feature order comparator.
+     */
+    @Test
+    public void testSerializationWithFeatureOrderComparator() {
+        // A comparator to sort the feature on their name length.
+        Comparator<EStructuralFeature> featuresComparator = new Comparator<EStructuralFeature>() {
+            @Override
+            public int compare(EStructuralFeature o1, EStructuralFeature o2) {
+                return o1.getName().length() - o2.getName().length();
+            }
+        };
+
+        this.options.put(JsonResource.OPTION_SAVE_FEATURES_ORDER_COMPARATOR, featuresComparator);
+        this.testSave("TestSerializationWithFeatureOrderComparator.xmi"); //$NON-NLS-1$
+
+    }
+
 }
diff --git a/...sources/unit/attributes/serializeoptions/TestSerializationWithFeatureOrderComparator.json b/...sources/unit/attributes/serializeoptions/TestSerializationWithFeatureOrderComparator.json
@@ -0,0 +1,22 @@
+{
+  "json": {
+    "version": "1.0",
+    "encoding": "utf-8"
+  },
+  "ns": {
+    "nodes": "http://www.obeo.fr/EMFJson"
+  },
+  "schemaLocation": {
+    "http://www.obeo.fr/EMFJson": "../../../nodes.ecore"
+  },
+  "content": [
+    {
+      "eClass": "nodes:NodeSingleValueAttribute",
+      "data": {
+        "singleIntAttribute": 12,
+        "singleStringAttribute": "String value",
+        "singleBooleanAttribute": true
+      }
+    }
+  ]
+}
diff --git a/...esources/unit/attributes/serializeoptions/TestSerializationWithFeatureOrderComparator.xmi b/...esources/unit/attributes/serializeoptions/TestSerializationWithFeatureOrderComparator.xmi
@@ -0,0 +1,10 @@
+<?xml version="1.0" encoding="ASCII"?>
+<nodes:NodeSingleValueAttribute
+    xmi:version="2.0"
+    xmlns:xmi="http://www.omg.org/XMI"
+    xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
+    xmlns:nodes="http://www.obeo.fr/EMFJson"
+    xsi:schemaLocation="http://www.obeo.fr/EMFJson ../../../nodes.ecore"
+    singleBooleanAttribute="true"
+    singleIntAttribute="12"
+    singleStringAttribute="String value"/>