feat(service-proxy): add service mixin

Implement "ServiceMixin" for applications. This mixin enhances component
registration so that service providers exported by a component are
automatically registered for dependency injection; and adds a new sugar
API for registering service providers manually:

    app.serviceProvider(MyServiceProvicer);

The method name "serviceProvider" was chosen deliberately to make it
clear that we are binding a Provider, not a class constructor. Compare
this to `app.repository(MyRepo)` that accepts a class construct. In the
future, we may add `app.service(MyService)` method if there is enough
user demand.

docs/site/Calling-other-APIs-and-Web-Services.md

@@ -60,19 +60,6 @@ Install the REST connector used by the new datasource:
 $ npm install --save loopback-connector-rest
 ```
 
-### Bind data sources to the context
-
-```ts
-import {Context} from '@loopback/context';
-
-const context = new Context();
-context.bind('dataSources.geoService').to(ds);
-```
-
-**NOTE**: Once we start to support declarative datasources with
-`@loopback/boot`, the datasource configuration files can be dropped into
-`src/datasources` to be discovered and bound automatically.
-
 ### Declare the service interface
 
 To promote type safety, we recommend you to declare data types and service
@@ -162,18 +149,20 @@ export class GeoServiceProvider implements Provider<GeoService> {
 }
 ```
 
-In your application setup, create an explicit binding for the geo service proxy:
+In your application, apply
+[ServiceMixin](http://apidocs.loopback.io/@loopback%2fdocs/service-proxy.html#ServiceMixin)
+and use `app.serviceProvider` API to create binding for the geo service proxy.
 
 ```ts
-app.bind('services.geo').toProvider(GeoServiceProvider);
+app.serviceProvider(GeoServiceProvider);
 ```
 
 Finally, modify the controller to receive our new service proxy in the
 constructor:
 
 ```ts
 export class MyController {
-  @inject('services.geo')
+  @inject('services.GeoService')
   private geoService: GeoService;
 }
 ```

docs/site/soap-calculator-tutorial-register-service.md

@@ -15,52 +15,43 @@ Injection)_.
 
 #### Importing the service and helper classes
 
-Add the following import statement after all the previous imports.
+Add the following import statements after all the previous imports.
 
 ```ts
+import {ServiceMixin} from '@loopback/service-proxy';
 import {CalculatorServiceProvider} from './services/calculator.service';
 ```
 
-Now change the following line to include a Constructor and Provider class from
-_LB4_ core.
+#### Applying `ServiceMixin` on our Application class
 
-```ts
-import {ApplicationConfig} from '@loopback/core';
-```
-
-change it to
+Modify the inheritance chain of our Application class as follows:
 
 ```ts
-import {ApplicationConfig, Constructor, Provider} from '@loopback/core';
+export class SoapCalculatorApplication extends BootMixin(
+  ServiceMixin(RepositoryMixin(RestApplication)),
+) {
+  // (no changes in application constructor or methods)
+}
 ```
 
 #### Registering the Service and bind it to a key
 
-Let's continue by adding the following generic method that we will use in order
-to register our service and any other service that we might work in the future.
-
-Notice that it removes the Provider key from the name of the service, so for our
-service name CalculatorServiceProvider, its key will become
-**services.CalculatorService** which matches the
+Let's continue by creating a method to register services used by our
+application. Notice that we are using `this.serviceProvider` method contributed
+by `ServiceMixin`, this method removes the suffix `Provider` from the class name
+and uses the remaining string as the binding key. For our service provider
+called `CalculatorServiceProvider`, the binding key becomes
+**services.CalculatorService** and matches the
 `@inject('services.CalculatorService')` decorator parameter we used in our
 controller.
 
 **NOTE:** This will be the method for now until we place the autodiscover and
 registration for services in the same way we do now for other artifacts in
 **LB4**.
 
-```ts
-service<T>(provider: Constructor<Provider<T>>) {
-    const key = `services.${provider.name.replace(/Provider$/, '')}`;
-    this.bind(key).toProvider(provider);
-  }
-```
-
-Now let's add a method that will make use of this generic `service<T>` method.
-
 ```ts
   setupServices() {
-    this.service(CalculatorServiceProvider);
+    this.serviceProvider(CalculatorServiceProvider);
   }
 ```
 
@@ -72,10 +63,10 @@ constructor after the `this.sequence(MySequence);` statement.
 this.setupServices();
 ```
 
-**Note:** We could have achieved the above result by just one line inside the
-setupServices() method, replacing the generic method. However, the generic one
-is more efficient when you need to register multiple services, to keep the
-_keys_ standard.
+**Note:** We could have achieved the above result by calling the following line
+inside the setupServices() method, replacing the method provided by the mixin.
+However, the mixin-provided method is more efficient when you need to register
+multiple services, to keep the _keys_ standard.
 
 ```ts
 this.bind('services.CalculatorService').toProvider(CalculatorServiceProvider);

docs/site/todo-tutorial-geocoding-service.md

@@ -149,8 +149,10 @@ to add few code snippets to our Application class to take care of this task.
 #### src/application.ts
 
 ```ts
+import {ServiceMixin} from '@loopback/service-proxy';
+
 export class TodoListApplication extends BootMixin(
-  RepositoryMixin(RestApplication),
+  ServiceMixin(RepositoryMixin(RestApplication)),
 ) {
   constructor(options?: ApplicationConfig) {
     super(options);
@@ -162,12 +164,7 @@ export class TodoListApplication extends BootMixin(
 
   // ADD THE FOLLOWING TWO METHODS
   setupServices() {
-    this.service(GeocoderServiceProvider);
-  }
-
-  service<T>(provider: Constructor<Provider<T>>) {
-    const key = `services.${provider.name.replace(/Provider$/, '')}`;
-    this.bind(key).toProvider(provider);
+    this.serviceProvider(GeocoderServiceProvider);
   }
 }
 ```

examples/soap-calculator/src/application.ts

@@ -1,12 +1,13 @@
 import {BootMixin} from '@loopback/boot';
-import {ApplicationConfig, Constructor, Provider} from '@loopback/core';
+import {ApplicationConfig} from '@loopback/core';
 import {RepositoryMixin} from '@loopback/repository';
 import {RestApplication} from '@loopback/rest';
+import {ServiceMixin} from '@loopback/service-proxy';
 import {MySequence} from './sequence';
 import {CalculatorServiceProvider} from './services/calculator.service';
 
 export class SoapCalculatorApplication extends BootMixin(
-  RepositoryMixin(RestApplication),
+  ServiceMixin(RepositoryMixin(RestApplication)),
 ) {
   constructor(options?: ApplicationConfig) {
     super(options);
@@ -30,11 +31,6 @@ export class SoapCalculatorApplication extends BootMixin(
   }
 
   setupServices() {
-    this.service(CalculatorServiceProvider);
-  }
-
-  service<T>(provider: Constructor<Provider<T>>) {
-    const key = `services.${provider.name.replace(/Provider$/, '')}`;
-    this.bind(key).toProvider(provider);
+    this.serviceProvider(CalculatorServiceProvider);
   }
 }

examples/todo/src/application.ts

@@ -4,14 +4,15 @@
 // License text available at https://opensource.org/licenses/MIT
 
 import {BootMixin} from '@loopback/boot';
-import {ApplicationConfig, Constructor, Provider} from '@loopback/core';
+import {ApplicationConfig} from '@loopback/core';
 import {RepositoryMixin} from '@loopback/repository';
 import {RestApplication} from '@loopback/rest';
+import {ServiceMixin} from '@loopback/service-proxy';
 import {MySequence} from './sequence';
 import {GeocoderServiceProvider} from './services';
 
 export class TodoListApplication extends BootMixin(
-  RepositoryMixin(RestApplication),
+  ServiceMixin(RepositoryMixin(RestApplication)),
 ) {
   constructor(options?: ApplicationConfig) {
     super(options);
@@ -36,14 +37,6 @@ export class TodoListApplication extends BootMixin(
   }
 
   setupServices() {
-    this.service(GeocoderServiceProvider);
-  }
-
-  // TODO(bajtos) app.service should be provided either by core Application
-  // class or a mixin provided by @loopback/service-proxy
-  // See https://github.com/strongloop/loopback-next/issues/1439
-  service<T>(provider: Constructor<Provider<T>>) {
-    const key = `services.${provider.name.replace(/Provider$/, '')}`;
-    this.bind(key).toProvider(provider);
+    this.serviceProvider(GeocoderServiceProvider);
   }
 }

packages/boot/src/booters/datasource.booter.ts

@@ -4,7 +4,11 @@
 // License text available at https://opensource.org/licenses/MIT
 
 import {CoreBindings} from '@loopback/core';
-import {AppWithRepository, juggler, Class} from '@loopback/repository';
+import {
+  ApplicationWithRepositories,
+  juggler,
+  Class,
+} from '@loopback/repository';
 import {inject} from '@loopback/context';
 import {ArtifactOptions} from '../interfaces';
 import {BaseArtifactBooter} from './base-artifact.booter';
@@ -22,7 +26,8 @@ import {BootBindings} from '../keys';
  */
 export class DataSourceBooter extends BaseArtifactBooter {
   constructor(
-    @inject(CoreBindings.APPLICATION_INSTANCE) public app: AppWithRepository,
+    @inject(CoreBindings.APPLICATION_INSTANCE)
+    public app: ApplicationWithRepositories,
     @inject(BootBindings.PROJECT_ROOT) public projectRoot: string,
     @inject(`${BootBindings.BOOT_OPTIONS}#datasources`)
     public datasourceConfig: ArtifactOptions = {},

packages/boot/src/booters/repository.booter.ts

@@ -5,7 +5,7 @@
 
 import {CoreBindings} from '@loopback/core';
 import {inject} from '@loopback/context';
-import {AppWithRepository} from '@loopback/repository';
+import {ApplicationWithRepositories} from '@loopback/repository';
 import {BaseArtifactBooter} from './base-artifact.booter';
 import {BootBindings} from '../keys';
 import {ArtifactOptions} from '../interfaces';
@@ -23,7 +23,8 @@ import {ArtifactOptions} from '../interfaces';
  */
 export class RepositoryBooter extends BaseArtifactBooter {
   constructor(
-    @inject(CoreBindings.APPLICATION_INSTANCE) public app: AppWithRepository,
+    @inject(CoreBindings.APPLICATION_INSTANCE)
+    public app: ApplicationWithRepositories,
     @inject(BootBindings.PROJECT_ROOT) public projectRoot: string,
     @inject(`${BootBindings.BOOT_OPTIONS}#repositories`)
     public repositoryOptions: ArtifactOptions = {},

packages/boot/test/unit/booters/datasource.booter.unit.ts

@@ -5,7 +5,10 @@
 
 import {expect, TestSandbox, sinon} from '@loopback/testlab';
 import {resolve} from 'path';
-import {AppWithRepository, RepositoryMixin} from '@loopback/repository';
+import {
+  ApplicationWithRepositories,
+  RepositoryMixin,
+} from '@loopback/repository';
 import {DataSourceBooter, DataSourceDefaults} from '../../../src';
 import {Application} from '@loopback/core';
 
@@ -33,7 +36,7 @@ describe('datasource booter unit tests', () => {
     );
 
     const booterInst = new DataSourceBooter(
-      normalApp as AppWithRepository,
+      normalApp as ApplicationWithRepositories,
       SANDBOX_PATH,
     );
 

packages/boot/test/unit/booters/repository.booter.unit.ts

@@ -5,7 +5,10 @@
 
 import {expect, TestSandbox, sinon} from '@loopback/testlab';
 import {Application} from '@loopback/core';
-import {RepositoryMixin, AppWithRepository} from '@loopback/repository';
+import {
+  RepositoryMixin,
+  ApplicationWithRepositories,
+} from '@loopback/repository';
 import {RepositoryBooter, RepositoryDefaults} from '../../../index';
 import {resolve} from 'path';
 
@@ -33,7 +36,7 @@ describe('repository booter unit tests', () => {
     );
 
     const booterInst = new RepositoryBooter(
-      normalApp as AppWithRepository,
+      normalApp as ApplicationWithRepositories,
       SANDBOX_PATH,
     );
 

packages/cli/generators/app/index.js

@@ -12,6 +12,7 @@ module.exports = class AppGenerator extends ProjectGenerator {
   constructor(args, opts) {
     super(args, opts);
     this.buildOptions.push('enableRepository');
+    this.buildOptions.push('enableServices');
   }
 
   _setupGenerator() {
@@ -27,6 +28,11 @@ module.exports = class AppGenerator extends ProjectGenerator {
       description: 'Include repository imports and RepositoryMixin',
     });
 
+    this.option('enableServices', {
+      type: Boolean,
+      description: 'Include service-proxy imports and ServiceMixin',
+    });
+
     return super._setupGenerator();
   }
 
@@ -80,6 +86,22 @@ module.exports = class AppGenerator extends ProjectGenerator {
     return super.promptOptions();
   }
 
+  buildAppClassMixins() {
+    if (this.shouldExit()) return false;
+    const {enableRepository, enableServices} = this.projectInfo || {};
+    if (!enableRepository && !enableServices) return;
+
+    let appClassWithMixins = 'RestApplication';
+    if (enableRepository) {
+      appClassWithMixins = `RepositoryMixin(${appClassWithMixins})`;
+    }
+    if (enableServices) {
+      appClassWithMixins = `ServiceMixin(${appClassWithMixins})`;
+    }
+
+    this.projectInfo.appClassWithMixins = appClassWithMixins;
+  }
+
   scaffold() {
     return super.scaffold();
   }

packages/cli/generators/app/templates/src/application.ts.ejs

@@ -4,11 +4,19 @@ import {ApplicationConfig} from '@loopback/core';
 import {RepositoryMixin} from '@loopback/repository';
 <% } -%>
 import {RestApplication} from '@loopback/rest';
+<% if (project.enableServices) { -%>
+import {ServiceMixin} from '@loopback/service-proxy';
+<% } -%>
 import {MySequence} from './sequence';
 
-export class <%= project.applicationName %> <% if (!project.enableRepository) {-%>extends BootMixin(RestApplication) {<% } else { -%>extends BootMixin(
-  RepositoryMixin(RestApplication),
+<% if (project.appClassWithMixins) { -%>
+export class <%= project.applicationName %> extends BootMixin(
+  <%= project.appClassWithMixins %>,
 ) {
+<%
+} else { // no optional mixins
+-%>
+export class <%= project.applicationName %> extends BootMixin(RestApplication) {
 <% } -%>
   constructor(options?: ApplicationConfig) {
     super(options);

packages/cli/generators/project/templates/package.json.ejs

@@ -78,9 +78,16 @@
     "@loopback/core": "<%= project.dependencies['@loopback/core'] -%>",
     "@loopback/dist-util": "<%= project.dependencies['@loopback/dist-util'] -%>",
     "@loopback/openapi-v3": "<%= project.dependencies['@loopback/openapi-v3'] -%>",
+<% if (project.enableRepository) { -%>
     "@loopback/repository": "<%= project.dependencies['@loopback/repository'] -%>",
-    "@loopback/rest": "<%= project.dependencies['@loopback/rest'] -%>"
+<% } -%>
+<% if (project.enableServices) { -%>
+    "@loopback/rest": "<%= project.dependencies['@loopback/rest'] -%>",
+    "@loopback/service-proxy": "<%= project.dependencies['@loopback/service-proxy'] -%>"
 <% } else { -%>
+    "@loopback/rest": "<%= project.dependencies['@loopback/rest'] -%>"
+<% } -%>
+<% } else { /* NOT AN APPLICATION */-%>
     "@loopback/core": "<%= project.dependencies['@loopback/core'] -%>",
     "@loopback/dist-util": "<%= project.dependencies['@loopback/dist-util'] -%>"
 <% } -%>

packages/cli/test/integration/generators/app.integration.js

@@ -35,7 +35,7 @@ describe('app-generator specific files', () => {
     );
     assert.fileContent(
       'src/application.ts',
-      /RepositoryMixin\(RestApplication\)/,
+      /ServiceMixin\(RepositoryMixin\(RestApplication\)\)/,
     );
     assert.fileContent('src/application.ts', /constructor\(/);
     assert.fileContent('src/application.ts', /this.projectRoot = __dirname/);