[feat] Add support for dynamic namespaces (#3195)

This follows #3187, with a slightly different API.

A dynamic namespace can be created with:

```js
io.of(/^\/dynamic-\d+$/).on('connect', (socket) => { /* ... */ });
```

Author: darrachequesne

docs/API.md

@@ -20,7 +20,6 @@
     - [server.onconnection(socket)](#serveronconnectionsocket)
     - [server.of(nsp)](#serverofnsp)
     - [server.close([callback])](#serverclosecallback)
-    - [server.useNamespaceValidator(fn)](#serverusenamespacevalidatorfn)
   - [Class: Namespace](#namespace)
     - [namespace.name](#namespacename)
     - [namespace.connected](#namespaceconnected)
@@ -293,7 +292,7 @@ Advanced use only. Creates a new `socket.io` client from the incoming engine.io
 
 #### server.of(nsp)
 
-  - `nsp` _(String)_
+  - `nsp` _(String|RegExp|Function)_
   - **Returns** `Namespace`
 
 Initializes and retrieves the given `Namespace` by its pathname identifier `nsp`. If the namespace was already initialized it returns it immediately.
@@ -302,6 +301,34 @@ Initializes and retrieves the given `Namespace` by its pathname identifier `nsp`
 const adminNamespace = io.of('/admin');
 ```
 
+A regex or a function can also be provided, in order to create namespace in a dynamic way:
+
+```js
+const dynamicNsp = io.of(/^\/dynamic-\d+$/).on('connect', (socket) => {
+  const newNamespace = socket.nsp; // newNamespace.name === '/dynamic-101'
+
+  // broadcast to all clients in the given sub-namespace
+  newNamespace.emit('hello');
+});
+
+// client-side
+const socket = io('/dynamic-101');
+
+// broadcast to all clients in each sub-namespace
+dynamicNsp.emit('hello');
+
+// use a middleware for each sub-namespace
+dynamicNsp.use((socket, next) => { /* ... */ });
+```
+
+With a function:
+
+```js
+io.of((name, query, next) => {
+  next(null, checkToken(query.token));
+}).on('connect', (socket) => { /* ... */ });
+```
+
 #### server.close([callback])
 
   - `callback` _(Function)_
@@ -322,22 +349,6 @@ server.listen(PORT); // PORT is free to use
 io = Server(server);
 ```
 
-#### server.useNamespaceValidator(fn)
-
-  - `fn` _(Function)_
-
-Sets up server middleware to validate whether a new namespace should be created.
-
-```js
-io.useNamespaceValidator((nsp, next) => {
-  if (nsp === 'dynamic') {
-    next(null, true);
-  } else {
-    next(new Error('Invalid namespace'));
-  }
-});
-```
-
 #### server.engine.generateId
 
 Overwrites the default method to generate your custom socket id.

lib/client.js

@@ -56,7 +56,7 @@ Client.prototype.setup = function(){
  * Connects a client to a namespace.
  *
  * @param {String} name namespace
- * @param {String} query the query parameters
+ * @param {Object} query the query parameters
  * @api private
  */
 
@@ -66,9 +66,9 @@ Client.prototype.connect = function(name, query){
     return this.doConnect(name, query);
   }
 
-  this.server.checkNamespace(name, (allow) => {
-    if (allow) {
-      debug('creating namespace %s', name);
+  this.server.checkNamespace(name, query, (dynamicNsp) => {
+    if (dynamicNsp) {
+      debug('dynamic namespace %s was created', dynamicNsp.name);
       this.doConnect(name, query);
     } else {
       debug('creation of namespace %s was denied', name);

lib/index.js

@@ -1,3 +1,4 @@
+'use strict';
 
 /**
  * Module dependencies.
@@ -12,6 +13,7 @@ var clientVersion = require('socket.io-client/package.json').version;
 var Client = require('./client');
 var Emitter = require('events').EventEmitter;
 var Namespace = require('./namespace');
+var ParentNamespace = require('./parent-namespace');
 var Adapter = require('socket.io-adapter');
 var parser = require('socket.io-parser');
 var debug = require('debug')('socket.io:server');
@@ -46,7 +48,7 @@ function Server(srv, opts){
   }
   opts = opts || {};
   this.nsps = {};
-  this.nspValidators = [];
+  this.parentNsps = new Map();
   this.path(opts.path || '/socket.io');
   this.serveClient(false !== opts.serveClient);
   this.parser = opts.parser || parser;
@@ -160,51 +162,35 @@ Server.prototype.set = function(key, val){
   return this;
 };
 
-/**
- * Sets up server middleware to validate incoming namespaces not already created on the server.
- *
- * @return {Server} self
- * @api public
- */
-
-Server.prototype.useNamespaceValidator = function(fn){
-  this.nspValidators.push(fn);
-  return this;
-};
-
 /**
  * Executes the middleware for an incoming namespace not already created on the server.
  *
- * @param name of incomming namespace
- * @param {Function} last fn call in the middleware
+ * @param {String} name name of incoming namespace
+ * @param {Object} query the query parameters
+ * @param {Function} fn callback
  * @api private
  */
 
-Server.prototype.checkNamespace = function(name, fn){
-  var fns = this.nspValidators.slice(0);
-  if (!fns.length) return fn(false);
-
-  var namespaceAllowed = false; // Deny unknown namespaces by default
-
-  function run(i){
-    fns[i](name, function(err, allow){
-      // upon error, short-circuit
-      if (err) return fn(false);
+Server.prototype.checkNamespace = function(name, query, fn){
+  if (this.parentNsps.size === 0) return fn(false);
 
-      // if one piece of middleware explicitly denies namespace, short-circuit
-      if (allow === false) return fn(false);
+  const keysIterator = this.parentNsps.keys();
 
-      namespaceAllowed = namespaceAllowed || allow === true;
-
-      // if no middleware left, summon callback
-      if (!fns[i + 1]) return fn(namespaceAllowed);
-
-      // go on to next
-      run(i + 1);
+  const run = () => {
+    let nextFn = keysIterator.next();
+    if (nextFn.done) {
+      return fn(false);
+    }
+    nextFn.value(name, query, (err, allow) => {
+      if (err || !allow) {
+        run();
+      } else {
+        fn(this.parentNsps.get(nextFn.value).createChild(name));
+      }
     });
-  }
+  };
 
-  run(0);
+  run();
 };
 
 /**
@@ -452,12 +438,24 @@ Server.prototype.onconnection = function(conn){
 /**
  * Looks up a namespace.
  *
- * @param {String} name nsp name
+ * @param {String|RegExp|Function} name nsp name
  * @param {Function} [fn] optional, nsp `connection` ev handler
  * @api public
  */
 
 Server.prototype.of = function(name, fn){
+  if (typeof name === 'function' || name instanceof RegExp) {
+    const parentNsp = new ParentNamespace(this);
+    debug('initializing parent namespace %s', parentNsp.name);
+    if (typeof name === 'function') {
+      this.parentNsps.set(name, parentNsp);
+    } else {
+      this.parentNsps.set((nsp, conn, next) => next(null, name.test(nsp)), parentNsp);
+    }
+    if (fn) parentNsp.on('connect', fn);
+    return parentNsp;
+  }
+
   if (String(name)[0] !== '/') name = '/' + name;
 
   var nsp = this.nsps[name];

lib/parent-namespace.js

@@ -0,0 +1,39 @@
+'use strict';
+
+const Namespace = require('./namespace');
+
+let count = 0;
+
+class ParentNamespace extends Namespace {
+
+  constructor(server) {
+    super(server, '/_' + (count++));
+    this.children = new Set();
+  }
+
+  initAdapter() {}
+
+  emit() {
+    const args = Array.prototype.slice.call(arguments);
+
+    this.children.forEach(nsp => {
+      nsp.rooms = this.rooms;
+      nsp.flags = this.flags;
+      nsp.emit.apply(nsp, args);
+    });
+    this.rooms = [];
+    this.flags = {};
+  }
+
+  createChild(name) {
+    const namespace = new Namespace(this.server, name);
+    namespace.fns = this.fns.slice(0);
+    this.listeners('connect').forEach(listener => namespace.on('connect', listener));
+    this.listeners('connection').forEach(listener => namespace.on('connection', listener));
+    this.children.add(namespace);
+    this.server.nsps[name] = namespace;
+    return namespace;
+  }
+}
+
+module.exports = ParentNamespace;

test/socket.io.js

@@ -1,3 +1,5 @@
+'use strict';
+
 var http = require('http').Server;
 var io = require('../lib');
 var fs = require('fs');
@@ -890,75 +892,55 @@ describe('socket.io', function(){
       });
     });
 
-    describe('dynamic', function () {
-      it('should allow connections to dynamic namespaces', function(done){
-        var srv = http();
-        var sio = io(srv);
+    describe('dynamic namespaces', function () {
+      it('should allow connections to dynamic namespaces with a regex', function(done){
+        const srv = http();
+        const sio = io(srv);
+        let count = 0;
         srv.listen(function(){
-          var namespace = '/dynamic';
-          var dynamic = client(srv, namespace);
-          sio.useNamespaceValidator(function(nsp, next) {
-            expect(nsp).to.be(namespace);
-            next(null, true);
+          const socket = client(srv, '/dynamic-101');
+          let dynamicNsp = sio.of(/^\/dynamic-\d+$/).on('connect', (socket) => {
+            expect(socket.nsp.name).to.be('/dynamic-101');
+            dynamicNsp.emit('hello', 1, '2', { 3: '4'});
+            if (++count === 4) done();
+          }).use((socket, next) => {
+            next();
+            if (++count === 4) done();
           });
-          dynamic.on('error', function(err) {
+          socket.on('error', function(err) {
             expect().fail();
           });
-          dynamic.on('connect', function() {
-            expect(sio.nsps[namespace]).to.be.a(Namespace);
-            expect(Object.keys(sio.nsps[namespace].sockets).length).to.be(1);
-            done();
+          socket.on('connect', () => {
+            if (++count === 4) done();
+          });
+          socket.on('hello', (a, b, c) => {
+            expect(a).to.eql(1);
+            expect(b).to.eql('2');
+            expect(c).to.eql({ 3: '4' });
+            if (++count === 4) done();
           });
         });
       });
 
-      it('should not allow connections to dynamic namespaces if not supported', function(done){
-        var srv = http();
-        var sio = io(srv);
+      it('should allow connections to dynamic namespaces with a function', function(done){
+        const srv = http();
+        const sio = io(srv);
         srv.listen(function(){
-          var namespace = '/dynamic';
-          sio.useNamespaceValidator(function(nsp, next) {
-            expect(nsp).to.be(namespace);
-            next(null, false);
-          });
-          sio.on('connect', function(socket) {
-            if (socket.nsp.name === namespace) {
-              expect().fail();
-            }
-          });
-
-          var dynamic = client(srv,namespace);
-          dynamic.on('connect', function(){
-            expect().fail();
-          });
-          dynamic.on('error', function(err) {
-            expect(err).to.be("Invalid namespace");
-            done();
-          });
+          const socket = client(srv, '/dynamic-101');
+          sio.of((name, query, next) => next(null, '/dynamic-101' === name));
+          socket.on('connect', done);
         });
       });
 
-      it('should not allow connections to dynamic namespaces if there is an error', function(done){
-        var srv = http();
-        var sio = io(srv);
+      it('should disallow connections when no dynamic namespace matches', function(done){
+        const srv = http();
+        const sio = io(srv);
         srv.listen(function(){
-          var namespace = '/dynamic';
-          sio.useNamespaceValidator(function(nsp, next) {
-            expect(nsp).to.be(namespace);
-            next(new Error(), true);
-          });
-          sio.on('connect', function(socket) {
-            if (socket.nsp.name === namespace) {
-              expect().fail();
-            }
-          });
-
-          var dynamic = client(srv,namespace);
-          dynamic.on('connect', function(){
-            expect().fail();
-          });
-          dynamic.on('error', function(err) {
-            expect(err).to.be("Invalid namespace");
+          const socket = client(srv, '/abc');
+          sio.of(/^\/dynamic-\d+$/);
+          sio.of((name, query, next) => next(null, '/dynamic-101' === name));
+          socket.on('error', (err) => {
+            expect(err).to.be('Invalid namespace');
             done();
           });
         });
@@ -1759,7 +1741,7 @@ describe('socket.io', function(){
         var socket = client(srv, { reconnection: false });
         sio.on('connection', function(s){
           s.conn.on('upgrade', function(){
-            console.log('\033[96mNote: warning expected and normal in test.\033[39m');
+            console.log('\u001b[96mNote: warning expected and normal in test.\u001b[39m');
             socket.io.engine.write('5woooot');
             setTimeout(function(){
               done();
@@ -1776,7 +1758,7 @@ describe('socket.io', function(){
         var socket = client(srv, { reconnection: false });
         sio.on('connection', function(s){
           s.conn.on('upgrade', function(){
-            console.log('\033[96mNote: warning expected and normal in test.\033[39m');
+            console.log('\u001b[96mNote: warning expected and normal in test.\u001b[39m');
             socket.io.engine.write('44["handle me please"]');
             setTimeout(function(){
               done();