From 8c0a43195ee52c1e7f1c73a94fffdcd998812dd2 Mon Sep 17 00:00:00 2001
From: Yi Zhang <yzhang@connectedlab.com>
Date: Fri, 25 Nov 2016 11:56:56 -0500
Subject: [PATCH] Add support for custom data when returning a list of all
 socket clients

---
 README.md |  6 ++++++
 index.js  | 53 +++++++++++++++++++++++++++++++++++++++++------------
 2 files changed, 47 insertions(+), 12 deletions(-)

diff --git a/README.md b/README.md
index 42f10a2..e6e1c01 100644
--- a/README.md
+++ b/README.md
@@ -62,6 +62,12 @@ that a regular `Adapter` does not
 
 Returns the list of client IDs connected to `rooms` across all nodes. See [Namespace#clients(fn:Function)](https://github.com/socketio/socket.io#namespaceclientsfnfunction)
 
+### RedisAdapter#setCustomClientHook(fn:Function)
+
+Sets a custom hook on the RedisAdapter#clients call, so that its callback
+provides custom data related to a client in addition to the array of client IDs.
+The input function takes a single argument, clientID.
+
 ## Client error handling
 
 Access the `pubClient` and `subClient` properties of the
diff --git a/index.js b/index.js
index 04df130..7c5d93b 100644
--- a/index.js
+++ b/index.js
@@ -165,10 +165,20 @@ function adapter(uri, opts){
         return;
       }
 
+      // construct client custom data from the custom hook
+      var clientsData = [];
+      for(var i=0; i<clients.length; i++) {
+        clientsData[i] = {
+          clientId: clients[i]
+        };
+        var clientInfo = Redis.customClientHook(clients[i]);
+        if(clientInfo) {
+            clientsData[i].clientInfo = clientInfo;
+        }
+      }
+
       var responseChn = prefix + '-sync#response#' + decoded.transaction;
-      var response = JSON.stringify({
-        clients : clients
-      });
+      var response = JSON.stringify(clientsData);
 
       pub.publish(responseChn, response);
     });
@@ -318,7 +328,7 @@ function adapter(uri, opts){
       numsub = numsub[1];
 
       var msg_count = 0;
-      var clients = {};
+      var clientsData = {};
 
       subJson.subscribe(responseChn, function(err) {
         if (err) {
@@ -334,7 +344,7 @@ function adapter(uri, opts){
 
         /*If there is no response for 1 second, return result;*/
         var timeout = setTimeout(function() {
-          if (fn) process.nextTick(fn.bind(null, null, Object.keys(clients)));
+          if (fn) process.nextTick(fn.bind(null, null, Object.keys(clientsData), clientsData));
         }, self.clientsTimeout);
 
         subJson.on(subEvent, function onEvent(channel, msg) {
@@ -344,12 +354,8 @@ function adapter(uri, opts){
           }
 
           var response = JSON.parse(msg);
-
-          //Ignore if response does not contain 'clients' key
-          if(!response.clients || !Array.isArray(response.clients)) return;
-          
-          for(var i = 0; i < response.clients.length; i++){
-            clients[response.clients[i]] = true;
+          for(var i = 0; i < response.length; i++){
+            clientsData[response[i].clientId] = response[i].clientInfo;
           }
 
           msg_count++;
@@ -358,7 +364,7 @@ function adapter(uri, opts){
             subJson.unsubscribe(responseChn);
             subJson.removeListener(subEvent, onEvent);
 
-            if (fn) process.nextTick(fn.bind(null, null, Object.keys(clients)));
+            if (fn) process.nextTick(fn.bind(null, null, Object.keys(clientsData), clientsData));
           }
         });
 
@@ -370,6 +376,29 @@ function adapter(uri, opts){
 
   };
 
+  /**
+   * Setter for the custom hook function.
+   *
+   * @param {Function} the function to be set as customClientHook
+   * @api public
+   */
+
+  Redis.setCustomClientHook = function(fn) {
+    Redis.customClientHook = fn;
+  }
+
+  /**
+   * A custom hook for redis consumer to overwrite to return custom data
+   * of a socket client.
+   *
+   * @param {String} client id
+   * @api private
+   */
+
+  Redis.customClientHook = function() {
+    return null;
+  }
+
   Redis.uid = uid;
   Redis.pubClient = pub;
   Redis.subClient = sub;