refactor(dart/transform): Use render Compiler concepts

Update `TemplateCompiler` transform step to use abstractions used by the
render `Compiler`. For example, template code is now loaded via an
instance of `TemplateLoader` and external resources are fetched via an
instance of `XHR`.

Author: Tim Blasi

modules/angular2/src/dom/browser_adapter.dart

@@ -296,7 +296,9 @@ class BrowserDomAdapter extends GenericBrowserDomAdapter {
   }
   String getEventKey(KeyboardEvent event) {
     int keyCode = event.keyCode;
-    return _keyCodeToKeyMap.containsKey(keyCode) ? _keyCodeToKeyMap[keyCode] : 'Unidentified';
+    return _keyCodeToKeyMap.containsKey(keyCode)
+        ? _keyCodeToKeyMap[keyCode]
+        : 'Unidentified';
   }
   getGlobalEventTarget(String target) {
     if (target == "window") {

modules/angular2/src/dom/html_adapter.dart

@@ -168,9 +168,8 @@ class Html5LibDomAdapter implements DomAdapter {
   getHost(el) {
     throw 'not implemented';
   }
-  clone(node) {
-    throw 'not implemented';
-  }
+  clone(node) => node.clone(true);
+
   hasProperty(element, String name) {
     throw 'not implemented';
   }

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

@@ -0,0 +1,26 @@
+library angular2.transform.template_compiler.compile_step_factory;
+
+import 'dart:async';
+import 'package:angular2/src/change_detection/parser/parser.dart' as ng;
+import 'package:angular2/src/render/api.dart';
+import 'package:angular2/src/render/dom/compiler/compile_step.dart';
+import 'package:angular2/src/render/dom/compiler/compile_step_factory.dart'
+    as base;
+import 'package:angular2/src/render/dom/compiler/property_binding_parser.dart';
+import 'package:angular2/src/render/dom/compiler/text_interpolation_parser.dart';
+import 'package:angular2/src/render/dom/compiler/view_splitter.dart';
+
+class CompileStepFactory implements base.CompileStepFactory {
+  final ng.Parser _parser;
+  CompileStepFactory(this._parser);
+
+  List<CompileStep> createSteps(
+      ViewDefinition template, List<Future> subTaskPromises) {
+    // TODO(kegluneq): Add other compile steps from default_steps.dart.
+    return [
+      new ViewSplitter(_parser),
+      new PropertyBindingParser(_parser),
+      new TextInterpolationParser(_parser)
+    ];
+  }
+}

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

@@ -5,22 +5,22 @@ import 'dart:async';
 import 'package:analyzer/analyzer.dart';
 import 'package:angular2/src/change_detection/parser/lexer.dart' as ng;
 import 'package:angular2/src/change_detection/parser/parser.dart' as ng;
+import 'package:angular2/src/render/api.dart';
 import 'package:angular2/src/render/dom/compiler/compile_pipeline.dart';
-import 'package:angular2/src/render/dom/compiler/compile_step.dart';
-import 'package:angular2/src/render/dom/compiler/property_binding_parser.dart';
-import 'package:angular2/src/render/dom/compiler/text_interpolation_parser.dart';
-import 'package:angular2/src/render/dom/compiler/view_splitter.dart';
-import 'package:angular2/src/dom/dom_adapter.dart';
+import 'package:angular2/src/render/dom/compiler/template_loader.dart';
+import "package:angular2/src/services/xhr.dart" show XHR;
 import 'package:angular2/src/reflection/reflection.dart';
+import 'package:angular2/src/services/url_resolver.dart';
 import 'package:angular2/src/transform/common/asset_reader.dart';
 import 'package:angular2/src/transform/common/logging.dart';
 import 'package:angular2/src/transform/common/names.dart';
 import 'package:angular2/src/transform/common/parser.dart';
 import 'package:angular2/src/transform/common/property_utils.dart' as prop;
 import 'package:barback/barback.dart';
-import 'package:code_transformers/assets.dart';
 
+import 'compile_step_factory.dart';
 import 'recording_reflection_capabilities.dart';
+import 'xhr_impl.dart';
 
 /// Reads the `.ng_deps.dart` file represented by `entryPoint` and parses any
 /// Angular 2 `View` annotations it declares to generate `getter`s,
@@ -30,28 +30,27 @@ import 'recording_reflection_capabilities.dart';
 Future<String> processTemplates(AssetReader reader, AssetId entryPoint) async {
   var parser = new Parser(reader);
   NgDeps ngDeps = await parser.parse(entryPoint);
-  var extractor = new _TemplateExtractor(reader, entryPoint);
+  var extractor = new _TemplateExtractor(new XhrImpl(reader, entryPoint));
 
   var registrations = new StringBuffer();
   for (var rType in ngDeps.registeredTypes) {
-    (await extractor.extractTemplates(rType))
-        .forEach((RecordingReflectionCapabilities values) {
-      var calls = _generateGetters('${rType.typeName}', values.getterNames);
-      if (calls.isNotEmpty) {
-        registrations.write('..${REGISTER_GETTERS_METHOD_NAME}'
-            '({${calls.join(', ')}})');
-      }
-      calls = _generateSetters('${rType.typeName}', values.setterNames);
-      if (calls.isNotEmpty) {
-        registrations.write('..${REGISTER_SETTERS_METHOD_NAME}'
-            '({${calls.join(', ')}})');
-      }
-      calls = _generateMethods('${rType.typeName}', values.methodNames);
-      if (calls.isNotEmpty) {
-        registrations.write('..${REGISTER_METHODS_METHOD_NAME}'
-            '({${calls.join(', ')}})');
-      }
-    });
+    var values = await extractor.extractTemplates(rType);
+    if (values == null) continue;
+    var calls = _generateGetters('${rType.typeName}', values.getterNames);
+    if (calls.isNotEmpty) {
+      registrations.write('..${REGISTER_GETTERS_METHOD_NAME}'
+          '({${calls.join(', ')}})');
+    }
+    calls = _generateSetters('${rType.typeName}', values.setterNames);
+    if (calls.isNotEmpty) {
+      registrations.write('..${REGISTER_SETTERS_METHOD_NAME}'
+          '({${calls.join(', ')}})');
+    }
+    calls = _generateMethods('${rType.typeName}', values.methodNames);
+    if (calls.isNotEmpty) {
+      registrations.write('..${REGISTER_METHODS_METHOD_NAME}'
+          '({${calls.join(', ')}})');
+    }
   }
 
   var code = ngDeps.code;
@@ -105,75 +104,52 @@ Iterable<String> _generateMethods(
 /// template code if necessary, and determines what values will be
 /// reflectively accessed from that template.
 class _TemplateExtractor {
-  final AssetReader _reader;
-  final AssetId _entryPoint;
-  final CompilePipeline _pipeline;
+  final CompileStepFactory _factory;
   final _TemplateExtractVisitor _visitor = new _TemplateExtractVisitor();
+  final TemplateLoader _loader;
 
-  _TemplateExtractor(this._reader, this._entryPoint)
-      : _pipeline = new CompilePipeline(_createCompileSteps());
-
-  static List<CompileStep> _createCompileSteps() {
-    var parser = new ng.Parser(new ng.Lexer());
-    // TODO(kegluneq): Add other compile steps from default_steps.dart.
-    return [
-      new ViewSplitter(parser),
-      new PropertyBindingParser(parser),
-      new TextInterpolationParser(parser)
-    ];
-  }
+  _TemplateExtractor(XHR xhr)
+      : _loader = new TemplateLoader(xhr, new UrlResolver()),
+        _factory = new CompileStepFactory(new ng.Parser(new ng.Lexer()));
 
-  Future<List<RecordingReflectionCapabilities>> extractTemplates(
-      RegisteredType t) async {
-    return (await _processRegisteredType(t)).map(_processTemplate).toList();
+  Future<RecordingReflectionCapabilities> extractTemplates(RegisteredType t) {
+    return _processTemplate(_processRegisteredType(t));
   }
 
-  RecordingReflectionCapabilities _processTemplate(String templateCode) {
+  Future<RecordingReflectionCapabilities> _processTemplate(
+      ViewDefinition viewDef) async {
+    // Check for "imperative views".
+    if (viewDef.template == null && viewDef.absUrl == null) return null;
+
     var recordingCapabilities = new RecordingReflectionCapabilities();
     var savedReflectionCapabilities = reflector.reflectionCapabilities;
     reflector.reflectionCapabilities = recordingCapabilities;
 
-    _pipeline.process(DOM.createTemplate(templateCode), templateCode);
+    // TODO(kegluneq): Rewrite url to inline `template` where possible.
+    // See [https://github.com/angular/angular/issues/1035].
+    var domNode = await _loader.load(viewDef);
+
+    new CompilePipeline(_factory.createSteps(viewDef, [])).process(
+        domNode, '$domNode');
 
     reflector.reflectionCapabilities = savedReflectionCapabilities;
     return recordingCapabilities;
   }
 
-  Future<List<String>> _processRegisteredType(RegisteredType t) async {
+  ViewDefinition _processRegisteredType(RegisteredType t) {
     _visitor.reset();
     t.annotations.accept(_visitor);
-    var toReturn = _visitor.inlineValues;
-    for (var url in _visitor.urlValues) {
-      var templateText = await _readUrlTemplate(url);
-      if (templateText != null) {
-        toReturn.add(templateText);
-      }
-    }
-    return toReturn;
-  }
-
-  // TODO(kegluneq): Rewrite these to `template` where possible.
-  // See [https://github.com/angular/angular/issues/1035].
-  Future<String> _readUrlTemplate(String url) async {
-    var assetId = uriToAssetId(_entryPoint, url, logger, null);
-    var templateExists = await _reader.hasInput(assetId);
-    if (!templateExists) {
-      logger.error('Could not read template at uri $url from $_entryPoint');
-      return null;
-    }
-    return await _reader.readAsString(assetId);
+    return _visitor.viewDef;
   }
 }
 
 /// Visitor responsible for processing the `annotations` property of a
-/// {@link RegisterType} object and pulling out template text.
+/// {@link RegisterType} object and pulling out template information.
 class _TemplateExtractVisitor extends Object with RecursiveAstVisitor<Object> {
-  final List<String> inlineValues = [];
-  final List<String> urlValues = [];
+  ViewDefinition viewDef = new ViewDefinition();
 
   void reset() {
-    inlineValues.clear();
-    urlValues.clear();
+    viewDef = new ViewDefinition();
   }
 
   @override
@@ -195,9 +171,16 @@ class _TemplateExtractVisitor extends Object with RecursiveAstVisitor<Object> {
       }
       var valueString = stringLiteralToString(node.expression);
       if (keyString == 'templateUrl') {
-        urlValues.add(valueString);
+        if (viewDef.absUrl != null) {
+          logger.error(
+              'Found multiple values for "templateUrl". Source: ${node}');
+        }
+        viewDef.absUrl = valueString;
       } else {
-        inlineValues.add(valueString);
+        if (viewDef.template != null) {
+          logger.error('Found multiple values for "template". Source: ${node}');
+        }
+        viewDef.template = valueString;
       }
     }
     return null;

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

@@ -0,0 +1,25 @@
+library angular2.transform.template_compiler.xhr_impl;
+
+import 'dart:async';
+import 'package:angular2/src/services/xhr.dart' show XHR;
+import 'package:angular2/src/transform/common/asset_reader.dart';
+import 'package:angular2/src/transform/common/logging.dart';
+import 'package:barback/barback.dart';
+import 'package:code_transformers/assets.dart';
+
+class XhrImpl implements XHR {
+  final AssetReader _reader;
+  final AssetId _entryPoint;
+
+  XhrImpl(this._reader, this._entryPoint);
+
+  Future<String> get(String url) async {
+    var assetId = uriToAssetId(_entryPoint, url, logger, null);
+    var templateExists = await _reader.hasInput(assetId);
+    if (!templateExists) {
+      logger.error('Could not read template at uri $url from $_entryPoint');
+      return null;
+    }
+    return await _reader.readAsString(assetId);
+  }
+}