Automatically generate IDs and UIDs for entities and properties

.github/workflows/dart.yml

@@ -3,20 +3,31 @@ name: Dart CI
 on: [push, pull_request]
 
 jobs:
-  build:
+  generator:
+    runs-on: ubuntu-latest
+    container:
+      image:  google/dart:latest
+    steps:
+      - uses: actions/checkout@v1
+      - name: Install dependencies
+        working-directory: bin/objectbox_model_generator
+        run: pub get
+      - name: Run tests
+        working-directory: bin/objectbox_model_generator
+        run: pub run test
 
+  lib:
+    needs: generator
     runs-on: ubuntu-latest
-
     container:
       image:  google/dart:latest
-
     steps:
-    - uses: actions/checkout@v1
-    - name: Install ObjectBox C-API
-      run: ./install.sh
-    - name: Install dependencies
-      run: pub get
-    - name: Generate ObjectBox models
-      run: pub run build_runner build
-    - name: Run tests
-      run: pub run test
+      - uses: actions/checkout@v1
+      - name: Install ObjectBox C-API
+        run: ./install.sh
+      - name: Install dependencies
+        run: pub get
+      - name: Generate ObjectBox models
+        run: pub run build_runner build
+      - name: Run tests
+        run: pub run test

.gitignore

@@ -4,10 +4,10 @@
 **/pubspec.lock
 misc/
 .idea/
-**/*.g.dart
 download/
 lib/*.dll
 lib/*.dylib
 lib/*.so
 lib/*.a
 .vscode/
+**/*.g.dart

bin/objectbox_model_generator/lib/src/code_chunks.dart

@@ -0,0 +1,46 @@
+import "package:objectbox/src/modelinfo/index.dart";
+
+class CodeChunks {
+  static String modelInfoLoader(String allModelsJsonFilename) => """
+      Map<int, ModelEntity> _allOBXModelEntities = null;
+
+      void _loadOBXModelEntities() {
+      if (FileSystemEntity.typeSync("objectbox-model.json") == FileSystemEntityType.notFound)
+          throw Exception("objectbox-model.json not found");
+
+      _allOBXModelEntities = {};
+      ModelInfo modelInfo = ModelInfo.fromMap(json.decode(new File("objectbox-model.json").readAsStringSync()));
+      modelInfo.entities.forEach((e) => _allOBXModelEntities[e.id.uid] = e);
+      }
+
+      ModelEntity _getOBXModelEntity(int entityUid) {
+      if (_allOBXModelEntities == null) _loadOBXModelEntities();
+      if (!_allOBXModelEntities.containsKey(entityUid))
+          throw Exception("entity uid missing in objectbox-model.json: \$entityUid");
+      return _allOBXModelEntities[entityUid];
+      }
+    """;
+
+  static String instanceBuildersReaders(ModelEntity readEntity) {
+    String name = readEntity.name;
+    return """
+        ModelEntity _${name}_OBXModelGetter() {
+          return _getOBXModelEntity(${readEntity.id.uid});
+        }
+
+        $name _${name}_OBXBuilder(Map<String, dynamic> members) {
+          $name r = new $name();
+          ${readEntity.properties.map((p) => "r.${p.name} = members[\"${p.name}\"];").join()}
+          return r;
+        }
+
+        Map<String, dynamic> _${name}_OBXReader($name inst) {
+          Map<String, dynamic> r = {};
+          ${readEntity.properties.map((p) => "r[\"${p.name}\"] = inst.${p.name};").join()}
+          return r;
+        }
+
+        const ${name}_OBXDefs = EntityDefinition<${name}>(_${name}_OBXModelGetter, _${name}_OBXReader, _${name}_OBXBuilder);
+      """;
+  }
+}

bin/objectbox_model_generator/lib/src/generator.dart

@@ -1,125 +1,128 @@
 import "dart:async";
+import "dart:convert";
+import "dart:io";
 import "package:analyzer/dart/element/element.dart";
 import "package:build/src/builder/build_step.dart";
 import "package:source_gen/source_gen.dart";
 
-import "package:objectbox/objectbox.dart";
+import "package:objectbox/objectbox.dart" as obx;
 import "package:objectbox/src/bindings/constants.dart";
 
-class EntityGenerator extends GeneratorForAnnotation<Entity> {
+import "code_chunks.dart";
+import "merge.dart";
+import "package:objectbox/src/modelinfo/index.dart";
+
+class EntityGenerator extends GeneratorForAnnotation<obx.Entity> {
+  static const ALL_MODELS_JSON = "objectbox-model.json";
+
+  // each .g.dart file needs to get a header with functions to load the ALL_MODELS_JSON file exactly once. Store the input .dart file ids this has already been done for here
+  List<String> entityHeaderDone = [];
+
+  Future<ModelInfo> _loadModelInfo() async {
+    if ((await FileSystemEntity.type(ALL_MODELS_JSON)) == FileSystemEntityType.notFound)
+      return ModelInfo.createDefault();
+    return ModelInfo.fromMap(json.decode(await (new File(ALL_MODELS_JSON).readAsString())));
+  }
+
   @override
-  FutureOr<String> generateForAnnotatedElement(Element elementBare, ConstantReader annotation, BuildStep buildStep) {
-    if (elementBare is! ClassElement)
-      throw InvalidGenerationSourceError("in target ${elementBare.name}: annotated element isn't a class");
-
-    // get basic entity info
-    var entity = Entity(id: annotation.read('id').intValue, uid: annotation.read('uid').intValue);
-    var element = elementBare as ClassElement;
-    var ret = """
-        const _${element.name}_OBXModel = {
-          "entity": {
-            "name": "${element.name}",
-            "id": ${entity.id},
-            "uid": ${entity.uid}
-          },
-          "properties": [
-      """;
-
-    // read all suitable annotated properties
-    var props = [];
-    String idPropertyName;
-    for (var f in element.fields) {
-      if (f.metadata == null || f.metadata.length != 1) // skip unannotated fields
-        continue;
-      var annotElmt = f.metadata[0].element as ConstructorElement;
-      var annotType = annotElmt.returnType.toString();
-      var annotVal = f.metadata[0].computeConstantValue();
-      var fieldTypeObj = annotVal.getField("type");
-      int fieldType = fieldTypeObj == null ? null : fieldTypeObj.toIntValue();
-
-      var prop = {
-        "name": f.name,
-        "id": annotVal.getField("id").toIntValue(),
-        "uid": annotVal.getField("uid").toIntValue(),
-        "flags": 0,
-      };
-
-      if (annotType == "Id") {
-        if (idPropertyName != null)
-          throw InvalidGenerationSourceError(
-              "in target ${elementBare.name}: has more than one properties annotated with @Id");
-        if (fieldType != null)
-          throw InvalidGenerationSourceError(
-              "in target ${elementBare.name}: programming error: @Id property may not specify a type");
-        if (f.type.toString() != "int")
-          throw InvalidGenerationSourceError(
-              "in target ${elementBare.name}: field with @Id property has type '${f.type.toString()}', but it must be 'int'");
-
-        fieldType = OBXPropertyType.Long;
-        prop["flags"] = OBXPropertyFlag.ID;
-        idPropertyName = f.name;
-      } else if (annotType == "Property") {
-        // nothing special here
-      } else {
-        // skip unknown annotations
-        continue;
-      }
+  Future<String> generateForAnnotatedElement(
+      Element elementBare, ConstantReader annotation, BuildStep buildStep) async {
+    try {
+      if (elementBare is! ClassElement)
+        throw InvalidGenerationSourceError("in target ${elementBare.name}: annotated element isn't a class");
+      var element = elementBare as ClassElement;
 
-      if (fieldType == null) {
-        var fieldTypeStr = f.type.toString();
-        if (fieldTypeStr == "int")
-          fieldType = OBXPropertyType.Int;
-        else if (fieldTypeStr == "String")
-          fieldType = OBXPropertyType.String;
-        else {
-          print(
-              "warning: skipping field '${f.name}' in entity '${element.name}', as it has the unsupported type '$fieldTypeStr'");
-          continue;
-        }
+      // load existing model from JSON file if possible
+      String inputFileId = buildStep.inputId.toString();
+      ModelInfo allModels = await _loadModelInfo();
+
+      // optionally add header for loading the .g.json file
+      var ret = "";
+      if (entityHeaderDone.indexOf(inputFileId) == -1) {
+        ret += CodeChunks.modelInfoLoader(ALL_MODELS_JSON);
+        entityHeaderDone.add(inputFileId);
       }
 
-      prop["type"] = fieldType;
-      props.add(prop);
-      ret += """
-          {
-            "name": "${prop['name']}",
-            "id": ${prop['id']},
-            "uid": ${prop['uid']},
-            "type": ${prop['type']},
-            "flags": ${prop['flags']},
-          },
-        """;
-    }
+      // process basic entity (note that allModels.createEntity is not used, as the entity will be merged)
+      ModelEntity readEntity = new ModelEntity(IdUid.empty(), null, element.name, [], allModels);
+      var entityUid = annotation.read("uid");
+      if (entityUid != null && !entityUid.isNull) readEntity.id.uid = entityUid.intValue;
+
+      // read all suitable annotated properties
+      bool hasIdProperty = false;
+      for (var f in element.fields) {
+        int fieldType, flags = 0;
+        int propUid;
 
-    // some checks on the entity's integrity
-    if (idPropertyName == null)
-      throw InvalidGenerationSourceError("in target ${elementBare.name}: has no properties annotated with @Id");
+        if (f.metadata != null && f.metadata.length == 1) {
+          var annotElmt = f.metadata[0].element as ConstructorElement;
+          var annotType = annotElmt.returnType.toString();
+          var annotVal = f.metadata[0].computeConstantValue();
+          var fieldTypeAnnot = null; // for the future, with custom type sizes allowed: annotVal.getField("type");
+          fieldType = fieldTypeAnnot == null ? null : fieldTypeAnnot.toIntValue();
+          propUid = annotVal.getField("uid").toIntValue();
 
-    // main code for instance builders and readers
-    ret += """
-          ],
-          "idPropertyName": "${idPropertyName}",
-        };
+          // find property flags
+          if (annotType == "Id") {
+            if (hasIdProperty)
+              throw InvalidGenerationSourceError(
+                  "in target ${elementBare.name}: has more than one properties annotated with @Id");
+            if (fieldType != null)
+              throw InvalidGenerationSourceError(
+                  "in target ${elementBare.name}: programming error: @Id property may not specify a type");
+            if (f.type.toString() != "int")
+              throw InvalidGenerationSourceError(
+                  "in target ${elementBare.name}: field with @Id property has type '${f.type.toString()}', but it must be 'int'");
 
-        ${element.name} _${element.name}_OBXBuilder(Map<String, dynamic> members) {
-          ${element.name} r = new ${element.name}();
-          ${props.map((p) => "r.${p['name']} = members[\"${p['name']}\"];").join()}
-          return r;
+            fieldType = OBXPropertyType.Long;
+            flags |= OBXPropertyFlag.ID;
+            hasIdProperty = true;
+          } else if (annotType == "Property") {
+            // nothing special
+          } else {
+            // skip unknown annotations
+            print(
+                "warning: skipping field '${f.name}' in entity '${element.name}', as it has the unknown annotation type '$annotType'");
+            continue;
+          }
         }
 
-        Map<String, dynamic> _${element.name}_OBXReader(${element.name} inst) {
-          Map<String, dynamic> r = {};
-          ${props.map((p) => "r[\"${p['name']}\"] = inst.${p['name']};").join()}
-          return r;
+        if (fieldType == null) {
+          var fieldTypeStr = f.type.toString();
+          if (fieldTypeStr == "int")
+            fieldType = OBXPropertyType.Int;
+          else if (fieldTypeStr == "String")
+            fieldType = OBXPropertyType.String;
+          else {
+            print(
+                "warning: skipping field '${f.name}' in entity '${element.name}', as it has the unsupported type '$fieldTypeStr'");
+            continue;
+          }
         }
 
-        const ${element.name}_OBXDefs = {
-          "model": _${element.name}_OBXModel,
-          "builder": _${element.name}_OBXBuilder,
-          "reader": _${element.name}_OBXReader,
-        };
-      """;
+        // create property (do not use readEntity.createProperty in order to avoid generating new ids)
+        ModelProperty prop = new ModelProperty(IdUid.empty(), f.name, fieldType, flags, readEntity);
+        if (propUid != null) prop.id.uid = propUid;
+        readEntity.properties.add(prop);
+      }
+
+      // some checks on the entity's integrity
+      if (!hasIdProperty)
+        throw InvalidGenerationSourceError("in target ${elementBare.name}: has no properties annotated with @Id");
 
-    return ret;
+      // merge existing model and annotated model that was just read, then write new final model to file
+      mergeEntity(allModels, readEntity);
+      new File(ALL_MODELS_JSON).writeAsString(new JsonEncoder.withIndent("  ").convert(allModels.toMap()));
+      readEntity = allModels.findEntityByName(element.name);
+      if (readEntity == null) return ret;
+
+      // main code for instance builders and readers
+      ret += CodeChunks.instanceBuildersReaders(readEntity);
+
+      return ret;
+    } catch (e, s) {
+      print(s);
+      rethrow;
+    }
   }
 }

bin/objectbox_model_generator/lib/src/merge.dart

@@ -0,0 +1,30 @@
+import "package:objectbox/src/modelinfo/index.dart";
+
+void _mergeProperty(ModelEntity entity, ModelProperty prop) {
+  ModelProperty propInModel = entity.findSameProperty(prop);
+  if (propInModel == null) {
+    entity.createCopiedProperty(prop);
+  } else {
+    propInModel.type = prop.type;
+    propInModel.flags = prop.flags;
+  }
+}
+
+void mergeEntity(ModelInfo modelInfo, ModelEntity readEntity) {
+  // "readEntity" only contains the entity info directly read from the annotations and Dart source (i.e. with missing ID, lastPropertyId etc.)
+  // "entityInModel" is the entity from the model with all correct id/uid, lastPropertyId etc.
+  ModelEntity entityInModel = modelInfo.findSameEntity(readEntity);
+
+  if (entityInModel == null) {
+    // in case the entity is created (i.e. when its given UID or name that does not yet exist), we are done, as nothing needs to be merged
+    modelInfo.createCopiedEntity(readEntity);
+  } else {
+    // here, the entity was found already and entityInModel and readEntity might differ, i.e. conflicts need to be resolved, so merge all properties first
+    readEntity.properties.forEach((p) => _mergeProperty(entityInModel, p));
+
+    // them remove all properties not present anymore in readEntity
+    entityInModel.properties
+        .where((p) => readEntity.findSameProperty(p) == null)
+        .forEach((p) => entityInModel.removeProperty(p));
+  }
+}

bin/objectbox_model_generator/pubspec.yaml

@@ -3,11 +3,12 @@ version: 0.3.0
 description: >-
   A preprocessor for Dart source files containing ObjectBox entity definitions.
 environment:
-  sdk: '>=2.5.0-dev.2.0 <3.0.0'
+  sdk: ">=2.5.0-dev.2.0 <3.0.0"
 dependencies:
-  build: '>=0.12.0 <2.0.0'
+  build: ">=0.12.0 <2.0.0"
   source_gen: ^0.9.0
   objectbox:
     path: ../..
 dev_dependencies:
-  build_runner: '>=0.9.0 <0.11.0'
+  build_runner: ">=0.9.0 <0.11.0"
+  test: ^1.0.0