带节点的Redis成员 [英] Redis smembers with node

问题描述

我有一个 Node，Express和Websockets 聊天应用程序.当前在聊天室中的用户的用户名存储在 Redis 中.当我输入 SMEMBERS'onlineUsers'时，从 redis-cli 中，我会返回当前房间中所有用户的列表:

I have a Node, Express, and Websockets chat app. The usernames of the users currently in the chatroom is stored to Redis. From the redis-cli when I type in SMEMBERS 'onlineUsers', I get back a list of all the users currently in the room:

127.0.0.1:6379> smembers 'onlineUsers'
 1) "jackson"
 2) "bubba yump"
 3) "dog"
 4) "rumba"
 5) "buba"

在主应用程序 javascript 文件中，我有一种获取当前用户的方法，因此可以在页面上显示他们:

In my main application javascript file I have a method to get the current users so I can display them on the page:

var showCurrentUsers = function(){
    $('#list_of_users').empty();
    $.getJSON('getUsers', function(data){
        console.log(data)
        for (var i in data){
             $('#list_of_users').append("<li> User: "+data[i]+"</li>")
        }
    });
}

在我的 Node 服务器文件中，我具有匹配的路由，但是 db.smembers 始终返回 true 而不是用户列表.

In my Node server file I have the matching route but db.smembers keeps returning true instead of a list of the users.

app.get('/getUsers', function(req,res){
   res.send(getOnlineUsers());
 });

// REDIS DATA
var getOnlineUsers = function(){
  return db.smembers("onlineUsers")
}

，这是用户名最初发布到数据库的位置:

and here is where the username is originally posted to the database:

  client.on("setUsername", function(user){
            pub.publish("chatting","A new user in connected:" + user);
            db.sadd("onlineUsers",user);
        }
    );

我知道用户名已正确发布到数据库，并且可以从 redis-cli 访问它们，但是我不确定为什么我的JSON调用返回 true 而不是列表.

I know that the usernames are correctly posting to the database, and I can access them from the redis-cli, but I'm not sure why my JSON call is returning true instead of the list.

推荐答案

(我假设您正在使用 https://github.com/mranney/node_redis )

节点redis客户端是异步的.您可以将其视为写入和删除的同步，但是要从数据库读取数据，您需要使用回调.

The node redis client is async. You can treat it as sync for writes and deletes, but to read from the db you need to use a callback.

app.get('/getUsers', function(req, res, next){
   getOnlineUsers(function (err, onlineUsers) {
     if (err) {
       return next(err);
     }
     res.send(onlineUsers);
   });
 });

// REDIS DATA
var getOnlineUsers = function(cb){
  return db.smembers("onlineUsers", cb);
}

这篇关于带节点的Redis成员的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！