feat(compiler): Backport DirectiveBinder API from #1178 to allow

gradual migration.

Originally authored by @yjbanov

Author: jbdeboer

lib/core/annotation.dart

@@ -11,6 +11,8 @@ export "package:angular/core/annotation_src.dart" show
     ShadowRootAware,
 
     Formatter,
+    DirectiveBinder,
+    DirectiveBinderFn,
     Injectable,
 
     Directive,

lib/core/annotation_src.dart

@@ -2,6 +2,13 @@ library angular.core.annotation_src;
 
 import "package:di/di.dart" show Injector, Visibility;
 
+abstract class DirectiveBinder {
+  bind(key, {Function toFactory, inject,
+      Visibility visibility: Directive.CHILDREN_VISIBILITY});
+}
+
+typedef void DirectiveBinderFn(DirectiveBinder module);
+
 RegExp _ATTR_NAME = new RegExp(r'\[([^\]]+)\]$');
 
 const String SHADOW_DOM_INJECTOR_NAME = 'SHADOW_INJECTOR';

lib/core_dom/element_binder.dart

@@ -33,6 +33,19 @@ class TemplateElementBinder extends ElementBinder {
   }
 }
 
+// TODO: This class exists for forwards API compatibility only.
+//       Remove it after migration to DI 2.0.
+class _DirectiveBinderImpl implements DirectiveBinder {
+  final module = new Module();
+
+  _DirectiveBinderImpl();
+
+  bind(key, {Function toFactory: DEFAULT_VALUE, List inject: null,
+      Visibility visibility: Directive.LOCAL_VISIBILITY}) {
+    module.bind(key, toFactory: toFactory, inject: inject,
+        visibility: visibility);
+  }
+}
 
 /**
  * ElementBinder is created by the Selector and is responsible for instantiating
@@ -297,8 +310,16 @@ class ElementBinder {
 
       _createDirectiveFactories(ref, nodeModule, node, nodesAttrsDirectives, nodeAttrs,
           visibility);
-      if (ref.annotation.module != null) {
-         nodeModule.install(ref.annotation.module());
+      // Choose between old-style Module-based API and new-style DirectiveBinder-base API
+      var moduleFn = ref.annotation.module;
+      if (moduleFn != null) {
+        if (moduleFn is DirectiveBinderFn) {
+          var binder = new _DirectiveBinderImpl();
+          moduleFn(binder);
+          nodeModule.install(binder.module);
+        } else {
+          nodeModule.install(moduleFn());
+        }
       }
     });
 

lib/core_dom/module_internal.dart

@@ -11,7 +11,8 @@ import 'package:perf_api/perf_api.dart';
 import 'package:angular/cache/module.dart';
 
 import 'package:angular/core/annotation.dart';
-import 'package:angular/core/annotation_src.dart' show SHADOW_DOM_INJECTOR_NAME;
+import 'package:angular/core/annotation_src.dart'
+    show SHADOW_DOM_INJECTOR_NAME, DirectiveBinder, DirectiveBinderFn;
 import 'package:angular/core/module_internal.dart';
 import 'package:angular/core/parser/parser.dart';
 import 'package:angular/core_dom/dom_util.dart' as util;

test/angular_spec.dart

@@ -105,6 +105,8 @@ main() {
         "angular.core.annotation_src.DetachAware",
         "angular.core.annotation_src.Directive",
         "angular.core.annotation_src.DirectiveAnnotation",
+        "angular.core.annotation_src.DirectiveBinder",
+        "angular.core.annotation_src.DirectiveBinderFn",
         "angular.core.annotation_src.Formatter",
         "angular.core.annotation_src.Injectable",
         "angular.core.annotation_src.NgAttr",