fix(docs): extract route how-to

docs/site/Customizing-routes.md

@@ -0,0 +1,95 @@
+---
+lang: en
+title: 'Customizing Routes'
+keywords: LoopBack 4.0, LoopBack 4, Node.js, TypeScript, OpenAPI, Express
+sidebar: lb4_sidebar
+permalink: /doc/en/lb4/Customizing-routes.html
+---
+
+In addition to defining routes at the Controller and operation level, you can
+also customize them at the application level.
+
+## Implementing HTTP redirects
+
+Both `RestServer` and `RestApplication` classes provide API for registering
+routes that will redirect clients to a given URL.
+
+Example use:
+
+{% include code-caption.html content="src/application.ts" %}
+
+```ts
+import {RestApplication} from '@loopback/rest';
+
+export class MyApplication extends RestApplication {
+  constructor(options: ApplicationConfig = {}) {
+    super(options);
+
+    // Use the default status code 303 See Other
+    this.redirect('/', '/home');
+
+    // Specify a custom status code 301 Moved Permanently
+    this.redirect('/stats', '/status', 301);
+  }
+}
+```
+
+## Mounting an Express Router
+
+If you have an existing [Express](https://expressjs.com/) application that you
+want to use with LoopBack 4, you can mount the Express application on top of a
+LoopBack 4 application. This way you can mix and match both frameworks, while
+using LoopBack as the host. You can also do the opposite and use Express as the
+host by mounting LoopBack 4 REST API on an Express application. See
+[Creating an Express Application with LoopBack REST API](express-with-lb4-rest-tutorial.md)
+for the tutorial.
+
+Mounting an Express router on a LoopBack 4 application can be done using the
+`mountExpressRouter` function provided by both
+[`RestApplication`](https://loopback.io/doc/en/lb4/apidocs.rest.restapplication.html)
+and [`RestServer`](https://loopback.io/doc/en/lb4/apidocs.rest.restserver.html).
+
+Example use:
+
+{% include note.html content="
+Make sure [express](https://www.npmjs.com/package/express) is installed.
+" %}
+
+{% include code-caption.html content="src/express-app.ts" %}
+
+```ts
+import {Request, Response} from 'express';
+import express from 'express';
+
+const legacyApp = express();
+
+// your existing Express routes
+legacyApp.get('/pug', function (_req: Request, res: Response) {
+  res.send('Pug!');
+});
+
+export {legacyApp};
+```
+
+{% include code-caption.html content="src/application.ts" %}
+
+```ts
+import {RestApplication} from '@loopback/rest';
+
+const {legacyApp} = require('./express-app');
+
+const openApiSpecForLegacyApp: RouterSpec = {
+  // insert your spec here, your 'paths', 'components', and 'tags' will be used
+};
+
+class MyApplication extends RestApplication {
+  constructor(/* ... */) {
+    // ...
+
+    this.mountExpressRouter('/dogs', legacyApp, openApiSpecForLegacyApp);
+  }
+}
+```
+
+Any routes you define in your `legacyApp` will be mounted on top of the `/dogs`
+base path, e.g. if you visit the `/dogs/pug` endpoint, you'll see `Pug!`.

docs/site/Route.md

@@ -201,87 +201,7 @@ class MySequence extends DefaultSequence {
 }
 ```
 
-## Implementing HTTP redirects
+## Related guides
 
-Both `RestServer` and `RestApplication` classes provide API for registering
-routes that will redirect clients to a given URL.
-
-Example use:
-
-{% include code-caption.html content="src/application.ts" %}
-
-```ts
-import {RestApplication} from '@loopback/rest';
-
-export class MyApplication extends RestApplication {
-  constructor(options: ApplicationConfig = {}) {
-    super(options);
-
-    // Use the default status code 303 See Other
-    this.redirect('/', '/home');
-
-    // Specify a custom status code 301 Moved Permanently
-    this.redirect('/stats', '/status', 301);
-  }
-}
-```
-
-## Mounting an Express Router
-
-If you have an existing [Express](https://expressjs.com/) application that you
-want to use with LoopBack 4, you can mount the Express application on top of a
-LoopBack 4 application. This way you can mix and match both frameworks, while
-using LoopBack as the host. You can also do the opposite and use Express as the
-host by mounting LoopBack 4 REST API on an Express application. See
-[Creating an Express Application with LoopBack REST API](express-with-lb4-rest-tutorial.md)
-for the tutorial.
-
-Mounting an Express router on a LoopBack 4 application can be done using the
-`mountExpressRouter` function provided by both
-[`RestApplication`](https://loopback.io/doc/en/lb4/apidocs.rest.restapplication.html)
-and [`RestServer`](https://loopback.io/doc/en/lb4/apidocs.rest.restserver.html).
-
-Example use:
-
-{% include note.html content="
-Make sure [express](https://www.npmjs.com/package/express) is installed.
-" %}
-
-{% include code-caption.html content="src/express-app.ts" %}
-
-```ts
-import {Request, Response} from 'express';
-import express from 'express';
-
-const legacyApp = express();
-
-// your existing Express routes
-legacyApp.get('/pug', function (_req: Request, res: Response) {
-  res.send('Pug!');
-});
-
-export {legacyApp};
-```
-
-{% include code-caption.html content="src/application.ts" %}
-
-```ts
-import {RestApplication} from '@loopback/rest';
-
-const legacyApp = require('./express-app').legacyApp;
-
-const openApiSpecForLegacyApp: RouterSpec = {
-  // insert your spec here, your 'paths', 'components', and 'tags' will be used
-};
-
-class MyApplication extends RestApplication {
-  constructor(/* ... */) {
-    // ...
-
-    this.mountExpressRouter('/dogs', legacyApp, openApiSpecForLegacyApp);
-  }
-}
-```
-
-Any routes you define in your `legacyApp` will be mounted on top of the `/dogs`
-base path, e.g. if you visit the `/dogs/pug` endpoint, you'll see `Pug!`.
+- [Implementing HTTP redirects](Customizing-routes.md#implementing-http-redirects)
+- [Mounting an Express Router](Customizing-routes.md#mounting-an-express-router)

docs/site/sidebars/lb4_sidebar.yml

@@ -196,6 +196,10 @@ children:
       url: Customizing-how-openapi-spec-is-served.html
       output: 'web, pdf'
 
+    - title: 'Customizing routes'
+      url: Customizing-routes.html
+      output: 'web, pdf'
+
     - title: 'Dynamically adding models, repositories, and controllers'
       url: Dynamic-models-repositories-controllers.html
       output: 'web, pdf'