[experimental] add integration with socket.io

CODEOWNERS

@@ -23,6 +23,7 @@ packages/repository/* @raymondfeng
 packages/repository-json-schema/* @bajtos
 packages/rest/* @bajtos @raymondfeng
 packages/service-proxy/* @raymondfeng
+packages/socketio/* @raymondfeng
 packages/testlab/* @bajtos
 examples/todo/* @bajtos @hacksparrow
 examples/express-composition/* @nabdelgadir

docs/apidocs.html

@@ -32,6 +32,7 @@ <h3>List of packages</h3>
         <li><a href="./repository-json-schema.html">@loopback/repository-json-schema</a></li>
         <li><a href="./rest.html">@loopback/rest</a></li>
         <li><a href="./service-proxy.html">@loopback/service-proxy</a></li>
+        <li><a href="./socketio.html">@loopback/socketio</a></li>
         <li><a href="./testlab.html">@loopback/testlab</a></li>
       </ul>
     </div>

docs/site/MONOREPO.md

@@ -33,6 +33,7 @@ The [loopback-next](https://github.com/strongloop/loopback-next) repository uses
 | [repository](https://github.com/strongloop/loopback-next/tree/master/packages/repository)                           | @loopback/repository                  | Define and implement a common set of interfaces for interacting with databases                                                                                                                                                                                                                   |
 | [rest](https://github.com/strongloop/loopback-next/tree/master/packages/rest)                                       | @loopback/rest                        | Expose controllers as REST endpoints and route REST API requests to controller methods                                                                                                                                                                                                           |
 | [service-proxy](https://github.com/strongloop/loopback-next/tree/master/packages/service-proxy)                     | @loopback/service-proxy               | A common set of interfaces for interacting with service oriented backends such as REST APIs, SOAP Web Services, and gRPC microservices                                                                                                                                                           |
+| [socketio](https://github.com/strongloop/loopback-next/tree/master/packages/socketio)                               | @loopback/socketio                    | Expose controllers as Socket.IO endpoints                                                                                                                                                                                                                                                        |
 | [testlab](https://github.com/strongloop/loopback-next/tree/master/packages/testlab)                                 | @loopback/testlab                     | A collection of test utilities we use to write LoopBack tests                                                                                                                                                                                                                                    |
 | [tslint-config](https://github.com/strongloop/loopback-next/tree/master/packages/tslint-config)                     | @loopback/tslint-config               | Shared TSLint config to enforce a consistent code style for LoopBack development                                                                                                                                                                                                                 |
 

experimental/socketio/LICENSE

@@ -0,0 +1,25 @@
+Copyright (c) IBM Corp. 2019. All Rights Reserved.
+Node module: @loopback/socketio
+This project is licensed under the MIT License, full text below.
+
+--------
+
+MIT license
+
+Permission is hereby granted, free of charge, to any person obtaining a copy
+of this software and associated documentation files (the "Software"), to deal
+in the Software without restriction, including without limitation the rights
+to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+copies of the Software, and to permit persons to whom the Software is
+furnished to do so, subject to the following conditions:
+
+The above copyright notice and this permission notice shall be included in
+all copies or substantial portions of the Software.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+THE SOFTWARE.

experimental/socketio/README.md

@@ -0,0 +1,66 @@
+# @loopback/socketio
+
+This module uses [socket.io](http://socket.io) to expose controllers as
+WebSocket friendly endpoints.
+
+## Use Cases
+
+1. A real time application would like to use WebSocket friendly APIs to manage
+   subscriptions, participants (rooms) and message exchanges.
+
+2. Make it easy for API developers to expose WebSocket friendly APIs without
+   learning a lot of low level concepts.
+
+3. Use it as a step stone to explore messaging oriented API paradigms and
+   programming models, such as pub/sub, eventing, streaming, and reactive.
+
+## High Level Design
+
+The package will provide the following key constructs:
+
+- SocketIOServer: A new server type that listens on incoming WebSocket
+  connections and dispatches messages to controllers that subscribe to the
+  namespace. Each server is attached to an http/https endpoint.
+
+- SocketIO controller: A controller class that is decorated with SocketIO
+  related metadata, including:
+
+  - Map to a namespace
+  - Connect/disconnect events
+  - Subscribe/consume messages
+  - Publish/produce messages
+
+- SocketIO middleware or sequence
+  - Allow common logic to intercept/process WebSocket messages
+
+## Basic Use
+
+1. Create a SocketIOServer
+2. Define a controller to handle socket.io events/messages
+3. Register the controller
+4. Discover socket.io controllers and mount them to the SocketIOServer
+   namespaces.
+
+## Installation
+
+```sh
+npm install --save @loopback/socketio
+```
+
+## Contributions
+
+- [Guidelines](https://github.com/strongloop/loopback-next/blob/master/docs/CONTRIBUTING.md)
+- [Join the team](https://github.com/strongloop/loopback-next/issues/110)
+
+## Tests
+
+Run `npm test` from the root folder.
+
+## Contributors
+
+See
+[all contributors](https://github.com/strongloop/loopback-next/graphs/contributors).
+
+## License
+
+MIT

experimental/socketio/docs.json

@@ -0,0 +1,7 @@
+{
+  "content": [
+    "index.ts",
+    "src/**/*.ts"
+  ],
+  "codeSectionDepth": 4
+}

experimental/socketio/index.d.ts

@@ -0,0 +1,6 @@
+// Copyright IBM Corp. 2019. All Rights Reserved.
+// Node module: @loopback/socketio
+// This file is licensed under the MIT License.
+// License text available at https://opensource.org/licenses/MIT
+
+export * from './dist';

experimental/socketio/index.js

@@ -0,0 +1,6 @@
+// Copyright IBM Corp. 2019. All Rights Reserved.
+// Node module: @loopback/socketio
+// This file is licensed under the MIT License.
+// License text available at https://opensource.org/licenses/MIT
+
+module.exports = require('./dist');

experimental/socketio/index.ts

@@ -0,0 +1,8 @@
+// Copyright IBM Corp. 2019. All Rights Reserved.
+// Node module: @loopback/socketio
+// This file is licensed under the MIT License.
+// License text available at https://opensource.org/licenses/MIT
+
+// DO NOT EDIT THIS FILE
+// Add any additional (re)exports to src/index.ts instead.
+export * from './src';