feat(template_cache_transformer): Implement template cache as a transformer

Implement the template cache generation as a transformer. This is implemented
as an optional transformer option generate_template_cache.

Closes #1646

Author: Ted Sander

lib/tools/transformer/options.dart

@@ -27,14 +27,19 @@ class TransformOptions {
    */
   final di.TransformOptions diOptions;
 
+  /// Option to generate the template cache.
+  final bool generateTemplateCache;
+
   TransformOptions({String sdkDirectory, List<String> htmlFiles,
       Map<String, String> templateUriRewrites,
-      di.TransformOptions diOptions}) :
+      di.TransformOptions diOptions, bool generateTemplateCache}) :
       sdkDirectory = sdkDirectory,
       htmlFiles = htmlFiles != null ? htmlFiles : [],
       templateUriRewrites = templateUriRewrites != null ?
           templateUriRewrites : {},
-      diOptions = diOptions {
+      diOptions = diOptions,
+      generateTemplateCache = generateTemplateCache != null ?
+          generateTemplateCache : false {
     if (sdkDirectory == null)
       throw new ArgumentError('sdkDirectory must be provided.');
   }

lib/tools/transformer/static_angular_generator.dart

@@ -39,7 +39,8 @@ class StaticAngularGenerator extends Transformer with ResolverTransformer {
       }
     }
 
-    var dynamicToStatic = new _NgDynamicToStaticVisitor(dynamicApp, transaction);
+    var dynamicToStatic = new _NgDynamicToStaticVisitor(
+        dynamicApp, transaction, options.generateTemplateCache);
     unit.accept(dynamicToStatic);
 
     var generatedFilePrefix = '${path.url.basenameWithoutExtension(id.path)}';
@@ -53,6 +54,11 @@ class StaticAngularGenerator extends Transformer with ResolverTransformer {
     _addImport(transaction, unit,
         '${generatedFilePrefix}_static_type_to_uri_mapper.dart',
         'generated_static_type_to_uri_mapper');
+    if (options.generateTemplateCache) {
+      _addImport(transaction, unit,
+          '${generatedFilePrefix}_generated_template_cache.dart',
+          'generated_template_cache');
+    }
 
     var printer = transaction.commit();
     var url = id.path.startsWith('lib/')
@@ -72,7 +78,9 @@ void _addImport(TextEditTransaction transaction, CompilationUnit unit,
 class _NgDynamicToStaticVisitor extends GeneralizingAstVisitor {
   final Element ngDynamicFn;
   final TextEditTransaction transaction;
-  _NgDynamicToStaticVisitor(this.ngDynamicFn, this.transaction);
+  final bool generateTemplateCache;
+  _NgDynamicToStaticVisitor(this.ngDynamicFn, this.transaction,
+      this.generateTemplateCache);
 
   visitMethodInvocation(MethodInvocation m) {
     if (m.methodName.bestElement == ngDynamicFn) {
@@ -90,6 +98,12 @@ class _NgDynamicToStaticVisitor extends GeneralizingAstVisitor {
            'generated_static_type_to_uri_mapper.typeToUriMapper'
           ].join(', ')
         );
+      if (generateTemplateCache) {
+        transaction.edit(
+            m.end,
+            m.end,
+            '..addModule(generated_template_cache.templateCacheModule)');
+      }
     }
     super.visitMethodInvocation(m);
   }

lib/tools/transformer/template_cache_generator.dart

@@ -0,0 +1,71 @@
+library angular_transformers.template_cache_generator;
+
+import 'dart:async';
+
+import 'package:angular/tools/transformer/options.dart';
+import 'package:angular/tools/transformer/referenced_uris.dart';
+import 'package:barback/barback.dart';
+import 'package:code_transformers/resolver.dart';
+import 'package:path/path.dart' as path;
+
+/// Transformer which gathers all templates from the Angular application and
+/// adds to the Template Cache.
+class TemplateCacheGenerator extends Transformer with ResolverTransformer {
+  static const String generatedFilename = '_generated_template_cache.dart';
+
+  final TransformOptions options;
+
+  TemplateCacheGenerator(this.options, Resolvers resolvers) {
+    this.resolvers = resolvers;
+  }
+
+  Future applyResolver(Transform transform, Resolver resolver) {
+    if (!options.generateTemplateCache) return new Future.value();
+
+    var asset = transform.primaryInput;
+    var id = asset.id;
+    var outputFilename = '${path.url.basenameWithoutExtension(id.path)}'
+        '$generatedFilename';
+    var outputPath = path.url.join(path.url.dirname(id.path), outputFilename);
+    var outputId = new AssetId(id.package, outputPath);
+    var outputBuffer = new StringBuffer();
+
+    return gatherReferencedUris(transform, resolver, options,
+            templatesOnly: false).then((templates) {
+      _writeTemplateCacheHeader(asset.id, outputBuffer);
+      templates.forEach((uri, contents) {
+        contents = contents.replaceAll("'''", r"\'\'\'");
+        outputBuffer.write("  r'$uri' : r'''\n$contents''',\n");
+      });
+      _writeTemplateCacheFooter(outputBuffer);
+      transform.addOutput(
+          new Asset.fromString(outputId, outputBuffer.toString()));
+    });
+  }
+
+  void _writeTemplateCacheHeader(AssetId id, StringSink sink) {
+    var libPath = path.url.withoutExtension(id.path).replaceAll('/', '.');
+    sink.write('''
+library ${id.package}.$libPath.generated_template_cache;
+
+import 'package:angular/angular.dart';
+import 'package:di/di.dart' show Module;
+
+Module get templateCacheModule =>
+    new Module()..bind(TemplateCache, toFactory: () {
+      var templateCache = new TemplateCache();
+      _cache.forEach((key, value) {
+        templateCache.put(key, new HttpResponse(200, value));
+      });
+      return templateCache;
+    });
+
+const Map<String, String> _cache = const <String, String> {
+''');
+  }
+
+  void _writeTemplateCacheFooter(StringSink sink) {
+    sink.write('''};
+''');
+  }
+}

lib/transformer.dart

@@ -6,6 +6,7 @@ import 'package:angular/tools/transformer/expression_generator.dart';
 import 'package:angular/tools/transformer/metadata_generator.dart';
 import 'package:angular/tools/transformer/static_angular_generator.dart';
 import 'package:angular/tools/transformer/html_dart_references_generator.dart';
+import 'package:angular/tools/transformer/template_cache_generator.dart';
 import 'package:angular/tools/transformer/type_relative_uri_generator.dart';
 import 'package:angular/tools/transformer/options.dart';
 import 'package:barback/barback.dart';
@@ -59,7 +60,26 @@ TransformOptions _parseSettings(Map args) {
       htmlFiles: _readStringListValue(args, 'html_files'),
       sdkDirectory: sdkDir,
       templateUriRewrites: _readStringMapValue(args, 'template_uri_rewrites'),
-      diOptions: diOptions);
+      diOptions: diOptions,
+      generateTemplateCache:
+          _readBoolValue(args, 'generate_template_cache', required: false));
+}
+
+_readBoolValue(Map args, String name, {bool required: true}) {
+  var value = args[name];
+  if (value == null) {
+    if (required) {
+      print('Angular transformer parameter "$name" '
+          'has no value in pubspec.yaml.');
+    }
+    return null;
+  }
+  if (value is! bool) {
+    print('Angular transformer parameter "$name" value '
+        'is not a bool in pubspec.yaml.');
+    return null;
+  }
+  return value;
 }
 
 _readStringValue(Map args, String name, {bool required: true}) {
@@ -123,6 +143,7 @@ Transformer _staticGenerator(TransformOptions options) {
       new TypeRelativeUriGenerator(options, resolvers),
       new ExpressionGenerator(options, resolvers),
       new MetadataGenerator(options, resolvers),
+      new TemplateCacheGenerator(options, resolvers),
       new StaticAngularGenerator(options, resolvers)
   ]);
 }

test/tools/transformer/static_angular_generator_spec.dart

@@ -2,25 +2,18 @@ library angular.test.tools.transformer.static_angular_generator_spec;
 
 import 'package:angular/tools/transformer/options.dart';
 import 'package:angular/tools/transformer/static_angular_generator.dart';
+import 'package:barback/barback.dart';
 import 'package:code_transformers/resolver.dart';
 import 'package:code_transformers/tests.dart' as tests;
 
-import 'package:unittest/unittest.dart' hide expect;
 import 'package:guinness/guinness.dart';
 
 main() {
   describe('StaticAngularGenerator', () {
-    var options = new TransformOptions(
-        sdkDirectory: dartSdkDirectory);
-
-    var resolvers = new Resolvers(dartSdkDirectory);
-
-    var phases = [
-      [new StaticAngularGenerator(options, resolvers)]
-    ];
 
     it('should modify applicationFactory', () {
-      return tests.applyTransformers(phases,
+      return tests.applyTransformers(
+          setupPhases(generateTemplateCache:false),
           inputs: {
             'angular|lib/application_factory.dart': libAngularDynamic,
             'di|lib/di.dart': libDI,
@@ -56,8 +49,46 @@ main() {
           });
     });
 
+    it('should modify applicationFactory with template cache', () {
+      return tests.applyTransformers(setupPhases(),
+          inputs: {
+            'angular|lib/application_factory.dart': libAngularDynamic,
+            'di|lib/di.dart': libDI,
+            'a|web/main.dart': '''
+import 'package:angular/application_factory.dart';
+import 'package:di/di.dart' show Module;
+
+class MyModule extends Module {}
+
+main() {
+  var app = applicationFactory()
+    .addModule(new MyModule())
+    .run();
+}
+'''
+          },
+          results: {
+            'a|web/main.dart': '''
+import 'package:angular/application_factory_static.dart';
+import 'package:di/di.dart' show Module;
+import 'main_static_expressions.dart' as generated_static_expressions;
+import 'main_static_metadata.dart' as generated_static_metadata;
+import 'main_static_type_to_uri_mapper.dart' as generated_static_type_to_uri_mapper;
+import 'main_generated_template_cache.dart' as generated_template_cache;
+
+class MyModule extends Module {}
+
+main() {
+  var app = staticApplicationFactory(generated_static_metadata.typeAnnotations, generated_static_expressions.getters, generated_static_expressions.setters, generated_static_expressions.symbols, generated_static_type_to_uri_mapper.typeToUriMapper)..addModule(generated_template_cache.templateCacheModule)
+    .addModule(new MyModule())
+    .run();
+}
+'''
+          });
+    });
+
     it('handles prefixed app imports', () {
-      return tests.applyTransformers(phases,
+      return tests.applyTransformers(setupPhases(),
           inputs: {
             'angular|lib/application_factory.dart': libAngularDynamic,
             'di|lib/di.dart': libDI,
@@ -81,11 +112,12 @@ import 'package:di/di.dart' show Module;
 import 'main_static_expressions.dart' as generated_static_expressions;
 import 'main_static_metadata.dart' as generated_static_metadata;
 import 'main_static_type_to_uri_mapper.dart' as generated_static_type_to_uri_mapper;
+import 'main_generated_template_cache.dart' as generated_template_cache;
 
 class MyModule extends Module {}
 
 main() {
-  var app = ng.staticApplicationFactory(generated_static_metadata.typeAnnotations, generated_static_expressions.getters, generated_static_expressions.setters, generated_static_expressions.symbols, generated_static_type_to_uri_mapper.typeToUriMapper)
+  var app = ng.staticApplicationFactory(generated_static_metadata.typeAnnotations, generated_static_expressions.getters, generated_static_expressions.setters, generated_static_expressions.symbols, generated_static_type_to_uri_mapper.typeToUriMapper)..addModule(generated_template_cache.templateCacheModule)
     .addModule(new MyModule())
     .run();
 }
@@ -95,8 +127,6 @@ main() {
   });
 }
 
-
-
 const String libAngularDynamic = '''
 library angular.app.factory;
 class _NgDynamicApp {}
@@ -107,3 +137,14 @@ applicationFactory() => new _DynamicApplication();
 const String libDI = '''
 class Module {}
 ''';
+
+List<List<Transformer>> setupPhases({bool generateTemplateCache: true}) {
+  var options = new TransformOptions(sdkDirectory: dartSdkDirectory,
+  generateTemplateCache: generateTemplateCache);
+
+  var resolvers = new Resolvers(dartSdkDirectory);
+
+  return [
+      [new StaticAngularGenerator(options, resolvers)]
+  ];
+}