feat(rest): allow factory for controller routes

packages/core/src/keys.ts

@@ -5,6 +5,7 @@
 
 import {BindingKey} from '@loopback/context';
 import {Application, ControllerClass} from './application';
+import {ControllerInstance} from '../../rest/src';
 
 /**
  * Namespace for core binding keys
@@ -53,4 +54,12 @@ export namespace CoreBindings {
    * request context
    */
   export const CONTROLLER_METHOD_META = 'controller.method.meta';
+
+  /**
+   * Binding key for the controller instance resolved in the current request
+   * context
+   */
+  export const CONTROLLER_CURRENT = BindingKey.create<ControllerInstance>(
+    'controller.current',
+  );
 }

packages/rest/src/http-handler.ts

@@ -15,6 +15,7 @@ import {
   ResolvedRoute,
   RouteEntry,
   ControllerClass,
+  ControllerFactory,
 } from './router/routing-table';
 import {ParsedRequest} from './internal-types';
 
@@ -33,8 +34,12 @@ export class HttpHandler {
     this.handleRequest = (req, res) => this._handleRequest(req, res);
   }
 
-  registerController(name: ControllerClass, spec: ControllerSpec) {
-    this._routes.registerController(name, spec);
+  registerController(
+    controllerCtor: ControllerClass,
+    spec: ControllerSpec,
+    controllerFactory?: ControllerFactory,
+  ) {
+    this._routes.registerController(controllerCtor, spec, controllerFactory);
   }
 
   registerRoute(route: RouteEntry) {

packages/rest/src/index.ts

@@ -14,6 +14,10 @@ export {
   ResolvedRoute,
   createResolvedRoute,
   parseRequestUrl,
+  ControllerClass,
+  ControllerInstance,
+  ControllerFactory,
+  createControllerFactory,
 } from './router/routing-table';
 
 export * from './providers';

packages/rest/src/rest.application.ts

@@ -10,7 +10,11 @@ import {Binding, Constructor} from '@loopback/context';
 import {format} from 'util';
 import {RestBindings} from './keys';
 import {RestServer, HttpRequestListener, HttpServerLike} from './rest.server';
-import {ControllerClass, RouteEntry} from './router/routing-table';
+import {
+  RouteEntry,
+  ControllerClass,
+  ControllerFactory,
+} from './router/routing-table';
 import {OperationObject, OpenApiSpec} from '@loopback/openapi-v3-types';
 
 export const ERR_NO_MULTI_SERVER = format(
@@ -97,13 +101,15 @@ export class RestApplication extends Application implements HttpServerLike {
    * @param spec The OpenAPI spec describing the endpoint (operation)
    * @param controller Controller constructor
    * @param methodName The name of the controller method
+   * @param factory A factory function to create controller instance
    */
   route(
     verb: string,
     path: string,
     spec: OperationObject,
     controller: ControllerClass,
     methodName: string,
+    factory?: ControllerFactory,
   ): Binding;
 
   /**
@@ -127,12 +133,20 @@ export class RestApplication extends Application implements HttpServerLike {
     spec?: OperationObject,
     controller?: ControllerClass,
     methodName?: string,
+    factory?: ControllerFactory,
   ): Binding {
     const server = this.restServer;
     if (typeof routeOrVerb === 'object') {
       return server.route(routeOrVerb);
     } else {
-      return server.route(routeOrVerb, path!, spec!, controller!, methodName!);
+      return server.route(
+        routeOrVerb,
+        path!,
+        spec!,
+        controller!,
+        methodName!,
+        factory,
+      );
     }
   }
 

packages/rest/src/rest.server.ts

@@ -10,6 +10,8 @@ import {
   Route,
   ControllerRoute,
   RouteEntry,
+  createControllerFactory,
+  ControllerFactory,
   ControllerClass,
 } from './router/routing-table';
 import {ParsedRequest} from './internal-types';
@@ -243,7 +245,8 @@ export class RestServer extends Context implements Server, HttpServerLike {
       if (apiSpec.components && apiSpec.components.schemas) {
         this._httpHandler.registerApiDefinitions(apiSpec.components.schemas);
       }
-      this._httpHandler.registerController(ctor, apiSpec);
+      const controllerFactory = createControllerFactory(b.key);
+      this._httpHandler.registerController(ctor, apiSpec, controllerFactory);
     }
 
     for (const b of this.find('routes.*')) {
@@ -292,7 +295,15 @@ export class RestServer extends Context implements Server, HttpServerLike {
         );
       }
 
-      const route = new ControllerRoute(verb, path, spec, ctor);
+      const controllerFactory = createControllerFactory(b.key);
+      const route = new ControllerRoute(
+        verb,
+        path,
+        spec,
+        ctor,
+        undefined,
+        controllerFactory,
+      );
       this._httpHandler.registerRoute(route);
       return;
     }
@@ -374,13 +385,15 @@ export class RestServer extends Context implements Server, HttpServerLike {
    * @param spec The OpenAPI spec describing the endpoint (operation)
    * @param controller Controller constructor
    * @param methodName The name of the controller method
+   * @param factory A factory function to create controller instance
    */
   route(
     verb: string,
     path: string,
     spec: OperationObject,
     controller: ControllerClass,
     methodName: string,
+    factory?: ControllerFactory,
   ): Binding;
 
   /**
@@ -404,6 +417,7 @@ export class RestServer extends Context implements Server, HttpServerLike {
     spec?: OperationObject,
     controller?: ControllerClass,
     methodName?: string,
+    controllerFactory?: ControllerFactory,
   ): Binding {
     if (typeof routeOrVerb === 'object') {
       const r = routeOrVerb;
@@ -439,7 +453,14 @@ export class RestServer extends Context implements Server, HttpServerLike {
     }
 
     return this.route(
-      new ControllerRoute(routeOrVerb, path, spec, controller, methodName),
+      new ControllerRoute(
+        routeOrVerb,
+        path,
+        spec,
+        controller,
+        methodName,
+        controllerFactory,
+      ),
     );
   }