refactor(change_detect): Move (de)hydrate logic into dedicated methods

Call new `(de)hydrateDirectives` methods from `(de)hydrate`. Add a null
implementation in `AbstractChangeDetector` and only override if
necessary for the specific change detector.

Update to #3248

modules/angular2/src/change_detection/abstract_change_detector.ts

@@ -60,8 +60,12 @@ export class AbstractChangeDetector implements ChangeDetector {
 
   hydrate(context: any, locals: Locals, directives: any, pipes: any): void {}
 
+  hydrateDirectives(directives: any): void {}
+
   dehydrate(): void {}
 
+  dehydrateDirectives(destroyPipes: boolean): void {}
+
   callOnAllChangesDone(): void {}
 
   _detectChangesInLightDomChildren(throwOnChange: boolean): void {
@@ -95,4 +99,4 @@ export class AbstractChangeDetector implements ChangeDetector {
                                  null;
     throw new ChangeDetectionError(proto, exception, stack, context);
   }
-}
+}

modules/angular2/src/change_detection/change_detection_jit_generator.ts

@@ -33,17 +33,18 @@ var ALREADY_CHECKED_ACCESSOR = "this.alreadyChecked";
 
 export class ChangeDetectorJITGenerator {
   _names: CodegenNameUtil;
+  _typeName: string;
 
   constructor(public id: string, public changeDetectionStrategy: string,
               public records: List<ProtoRecord>, public directiveRecords: List<any>,
               private generateCheckNoChanges: boolean) {
     this._names = new CodegenNameUtil(this.records, this.directiveRecords, 'this._', UTIL);
+    this._typeName = sanitizeName(`ChangeDetector_${this.id}`);
   }
 
   generate(): Function {
-    var typeName = sanitizeName(`ChangeDetector_${this.id}`);
     var classDefinition = `
-      var ${typeName} = function ${typeName}(dispatcher, protos, directiveRecords) {
+      var ${this._typeName} = function ${this._typeName}(dispatcher, protos, directiveRecords) {
         ${ABSTRACT_CHANGE_DETECTOR}.call(this, ${JSON.stringify(this.id)}, dispatcher);
         ${PROTOS_ACCESSOR} = protos;
         ${DIRECTIVES_ACCESSOR} = directiveRecords;
@@ -51,12 +52,12 @@ export class ChangeDetectorJITGenerator {
         ${CURRENT_PROTO} = null;
         ${PIPES_ACCESSOR} = null;
         ${ALREADY_CHECKED_ACCESSOR} = false;
-        ${this._names.genDehydrateFields()}
+        this.dehydrateDirectives(false);
       }
 
-      ${typeName}.prototype = Object.create(${ABSTRACT_CHANGE_DETECTOR}.prototype);
+      ${this._typeName}.prototype = Object.create(${ABSTRACT_CHANGE_DETECTOR}.prototype);
 
-      ${typeName}.prototype.detectChangesInRecords = function(throwOnChange) {
+      ${this._typeName}.prototype.detectChangesInRecords = function(throwOnChange) {
         if (!this.hydrated()) {
           ${UTIL}.throwDehydrated();
         }
@@ -67,7 +68,7 @@ export class ChangeDetectorJITGenerator {
         }
       }
 
-      ${typeName}.prototype.__detectChangesInRecords = function(throwOnChange) {
+      ${this._typeName}.prototype.__detectChangesInRecords = function(throwOnChange) {
         ${CURRENT_PROTO} = null;
 
         ${this._names.genInitLocals()}
@@ -81,35 +82,37 @@ export class ChangeDetectorJITGenerator {
         ${ALREADY_CHECKED_ACCESSOR} = true;
       }
 
-      ${this._genCheckNoChanges(typeName)}
+      ${this._genCheckNoChanges()}
 
-      ${typeName}.prototype.callOnAllChangesDone = function() {
+      ${this._typeName}.prototype.callOnAllChangesDone = function() {
         ${this._genCallOnAllChangesDoneBody()}
       }
 
-      ${typeName}.prototype.hydrate = function(context, locals, directives, pipes) {
+      ${this._typeName}.prototype.hydrate = function(context, locals, directives, pipes) {
         ${MODE_ACCESSOR} = "${ChangeDetectionUtil.changeDetectionMode(this.changeDetectionStrategy)}";
         ${this._names.getContextName()} = context;
         ${LOCALS_ACCESSOR} = locals;
-        ${this._genHydrateDirectives()}
-        ${this._genHydrateDetectors()}
+        this.hydrateDirectives(directives);
         ${PIPES_ACCESSOR} = pipes;
         ${ALREADY_CHECKED_ACCESSOR} = false;
       }
 
-      ${typeName}.prototype.dehydrate = function() {
-        ${this._names.genPipeOnDestroy()}
-        ${this._names.genDehydrateFields()}
+      ${this._maybeGenHydrateDirectives()}
+
+      ${this._typeName}.prototype.dehydrate = function() {
+        this.dehydrateDirectives(true);
         ${LOCALS_ACCESSOR} = null;
         ${PIPES_ACCESSOR} = null;
       }
 
-      ${typeName}.prototype.hydrated = function() {
+      ${this._maybeGenDehydrateDirectives()}
+
+      ${this._typeName}.prototype.hydrated = function() {
         return ${this._names.getContextName()} !== null;
       }
 
       return function(dispatcher) {
-        return new ${typeName}(dispatcher, protos, directiveRecords);
+        return new ${this._typeName}(dispatcher, protos, directiveRecords);
       }
     `;
 
@@ -118,6 +121,29 @@ export class ChangeDetectorJITGenerator {
         AbstractChangeDetector, ChangeDetectionUtil, this.records, this.directiveRecords);
   }
 
+  _maybeGenDehydrateDirectives(): string {
+    var destroyPipesCode = this._names.genPipeOnDestroy();
+    if (destroyPipesCode) {
+      destroyPipesCode = `if (destroyPipes) { ${destroyPipesCode} }`;
+    }
+    var dehydrateFieldsCode = this._names.genDehydrateFields();
+    if (!destroyPipesCode && !dehydrateFieldsCode) return '';
+    return `${this._typeName}.prototype.dehydrateDirectives = function(destroyPipes) {
+        ${destroyPipesCode}
+        ${dehydrateFieldsCode}
+    }`;
+  }
+
+  _maybeGenHydrateDirectives(): string {
+    var hydrateDirectivesCode = this._genHydrateDirectives();
+    var hydrateDetectorsCode = this._genHydrateDetectors();
+    if (!hydrateDirectivesCode && !hydrateDetectorsCode) return '';
+    return `${this._typeName}.prototype.hydrateDirectives = function(directives) {
+      ${hydrateDirectivesCode}
+      ${hydrateDetectorsCode}
+    }`;
+  }
+
   _genHydrateDirectives(): string {
     var directiveFieldNames = this._names.getAllDirectiveNames();
     var lines = ListWrapper.createFixedSize(directiveFieldNames.length);
@@ -345,9 +371,9 @@ export class ChangeDetectorJITGenerator {
     }
   }
 
-  _genCheckNoChanges(typeName: string): string {
+  _genCheckNoChanges(): string {
     if (this.generateCheckNoChanges) {
-      return `${typeName}.prototype.checkNoChanges = function() { this.runDetectChanges(true); }`;
+      return `${this._typeName}.prototype.checkNoChanges = function() { this.runDetectChanges(true); }`;
     } else {
       return '';
     }

modules/angular2/src/transform/template_compiler/change_detector_codegen.dart

@@ -115,7 +115,7 @@ class _CodegenState {
             this.$_PROTOS_ACCESSOR,
             this.$_DIRECTIVES_ACCESSOR)
           : super(${_encodeValue(_changeDetectorDefId)}, $_DISPATCHER_ACCESSOR) {
-          ${_names.genDehydrateFields()}
+          dehydrateDirectives(false);
         }
 
         void detectChangesInRecords(throwOnChange) {
@@ -123,9 +123,9 @@ class _CodegenState {
             $_UTIL.throwDehydrated();
           }
           try {
-            this.__detectChangesInRecords(throwOnChange);
+            __detectChangesInRecords(throwOnChange);
           } catch (e, s) {
-            this.throwError($_CURRENT_PROTO, e, s);
+            throwError($_CURRENT_PROTO, e, s);
           }
         }
 
@@ -151,19 +151,21 @@ class _CodegenState {
           $_MODE_ACCESSOR = '$_changeDetectionMode';
           ${_names.getContextName()} = context;
           $_LOCALS_ACCESSOR = locals;
-          ${_genHydrateDirectives()}
-          ${_genHydrateDetectors()}
+          hydrateDirectives(directives);
           $_ALREADY_CHECKED_ACCESSOR = false;
           $_PIPES_ACCESSOR = pipes;
         }
 
+        ${_maybeGenHydrateDirectives()}
+
         void dehydrate() {
-          ${_names.genPipeOnDestroy()}
-          ${_names.genDehydrateFields()}
+          dehydrateDirectives(true);
           $_LOCALS_ACCESSOR = null;
           $_PIPES_ACCESSOR = null;
         }
 
+        ${_maybeGenDehydrateDirectives()}
+
         hydrated() => ${_names.getContextName()} != null;
 
         static $_GEN_PREFIX.ProtoChangeDetector
@@ -184,6 +186,34 @@ class _CodegenState {
     ''');
   }
 
+  String _maybeGenDehydrateDirectives() {
+    var destroyPipesParamName = 'destroyPipes';
+    var destroyPipesCode = _names.genPipeOnDestroy();
+    if (destroyPipesCode.isNotEmpty) {
+      destroyPipesCode = 'if (${destroyPipesParamName}) { '
+          '${destroyPipesCode}'
+          '}';
+    }
+    var dehydrateFieldsCode = _names.genDehydrateFields();
+    if (destroyPipesCode.isEmpty && dehydrateFieldsCode.isEmpty) return '';
+    return 'void dehydrateDirectives(${destroyPipesParamName}) {'
+        '${destroyPipesCode}'
+        '${dehydrateFieldsCode}'
+        '}';
+  }
+
+  String _maybeGenHydrateDirectives() {
+    var hydrateDirectivesCode = _genHydrateDirectives();
+    var hydrateDetectorsCode = _genHydrateDetectors();
+    if (hydrateDirectivesCode.isEmpty && hydrateDetectorsCode.isEmpty) {
+      return '';
+    }
+    return 'void hydrateDirectives(directives) { '
+        '$hydrateDirectivesCode'
+        '$hydrateDetectorsCode'
+        '}';
+  }
+
   String _genHydrateDirectives() {
     var buf = new StringBuffer();
     var directiveFieldNames = _names.getAllDirectiveNames();
@@ -412,7 +442,7 @@ class _CodegenState {
 
   String _genCheckNoChanges() {
     if (this._generateCheckNoChanges) {
-      return 'void checkNoChanges() { this.runDetectChanges(true); }';
+      return 'void checkNoChanges() { runDetectChanges(true); }';
     } else {
       return '';
     }

modules/angular2/test/transform/integration/two_annotations_files/expected/bar.ng_deps.dart

@@ -36,8 +36,7 @@ class _MyComponent_ChangeDetector0 extends _gen.AbstractChangeDetector {
   _MyComponent_ChangeDetector0(
       dynamic dispatcher, this._protos, this._directiveRecords)
       : super("MyComponent_comp_0", dispatcher) {
-    _context = null;
-    _myNum0 = _interpolate1 = _gen.ChangeDetectionUtil.uninitialized;
+    dehydrateDirectives(false);
   }
 
   void detectChangesInRecords(throwOnChange) {
@@ -45,9 +44,9 @@ class _MyComponent_ChangeDetector0 extends _gen.AbstractChangeDetector {
       _gen.ChangeDetectionUtil.throwDehydrated();
     }
     try {
-      this.__detectChangesInRecords(throwOnChange);
+      __detectChangesInRecords(throwOnChange);
     } catch (e, s) {
-      this.throwError(currentProto, e, s);
+      throwError(currentProto, e, s);
     }
   }
 
@@ -92,7 +91,7 @@ class _MyComponent_ChangeDetector0 extends _gen.AbstractChangeDetector {
   }
 
   void checkNoChanges() {
-    this.runDetectChanges(true);
+    runDetectChanges(true);
   }
 
   void callOnAllChangesDone() {
@@ -103,18 +102,22 @@ class _MyComponent_ChangeDetector0 extends _gen.AbstractChangeDetector {
     mode = 'ALWAYS_CHECK';
     _context = context;
     _locals = locals;
-
+    hydrateDirectives(directives);
     _alreadyChecked = false;
     _pipes = pipes;
   }
 
   void dehydrate() {
-    _context = null;
-    _myNum0 = _interpolate1 = _gen.ChangeDetectionUtil.uninitialized;
+    dehydrateDirectives(true);
     _locals = null;
     _pipes = null;
   }
 
+  void dehydrateDirectives(destroyPipes) {
+    _context = null;
+    _myNum0 = _interpolate1 = _gen.ChangeDetectionUtil.uninitialized;
+  }
+
   hydrated() => _context != null;
 
   static _gen.ProtoChangeDetector newProtoChangeDetector(