feat(router): add interfaces for route definitions in RouteConfig

Closes #2261

modules/angular2/src/router/route_config_nomalizer.ts

@@ -0,0 +1,46 @@
+import {AsyncRoute, Route, Redirect, RouteDefinition} from './route_config_decorator';
+import {ComponentDefinition} from './route_definition';
+import {Type, BaseException} from 'angular2/src/facade/lang';
+
+/**
+ * Given a JS Object that represents... returns a corresponding Route, AsyncRoute, or Redirect
+ */
+export function normalizeRouteConfig(config: RouteDefinition): RouteDefinition {
+  if (config instanceof Route || config instanceof Redirect || config instanceof AsyncRoute) {
+    return <RouteDefinition>config;
+  }
+
+  if ((!config.component) == (!config.redirectTo)) {
+    throw new BaseException(
+        `Route config should contain exactly one 'component', or 'redirectTo' property`);
+  }
+  if (config.component) {
+    if (typeof config.component == 'object') {
+      let componentDefinitionObject = <ComponentDefinition>config.component;
+      if (componentDefinitionObject.type == 'constructor') {
+        return new Route({
+          path: config.path,
+          component:<Type>componentDefinitionObject.constructor,
+          as: config.as
+        });
+      } else if (componentDefinitionObject.type == 'loader') {
+        return new AsyncRoute(
+            {path: config.path, loader: componentDefinitionObject.loader, as: config.as});
+      } else {
+        throw new BaseException(
+            `Invalid component type '${componentDefinitionObject.type}'. Valid types are "constructor" and "loader".`);
+      }
+    }
+    return new Route(<{
+      path: string;
+      component: Type;
+      as?: string
+    }>config);
+  }
+
+  if (config.redirectTo) {
+    return new Redirect({path: config.path, redirectTo: config.redirectTo});
+  }
+
+  return config;
+}