node_redis client - Cannot return out values from a query
I'm going crazy with a problem which I can not find solution. I can not return out values from a redis query. I am using node_redis client (http://redis.js.org/) as redis driver for Node.JS.
The problem is: I wrote a function for get the user status connection and return it for take the value from other function.
//CHECK USER STATUS
exports.checkUserStatus = function(uid){
redis.multi()
.sismember('users:online',uid)
.sismember('users:iddle', uid)
.sismember('users:out', uid)
.sismember('users:locked', uid)
.exec(function(err, res){
res.forEach(function(res, index){
if(res != 0){
switch(index){
case 0:
return 'online';
break;
case 1:
return 'iddle';
break;
case 2:
return 'out';
break;
case 3:
return 'locked';
break;
default:
return 'offline';
}
}
});
})
}
But function return nothing!. If I replace the return line with a console.log(), it work! but I don't need a console.log(), I need take the value.
I tried too create a variable outside of the query and set it from inside and then return it but, it doesn't work.
Somebody know how may I do that?
Thank you!
Answers:
I'm not a redis expert but ... maybe you simply missing the return keyword?
var result;
exports.checkUserStatus = function(uid){
redis.multi()
...
.exec(function(err, res){
res.forEach(function(res, index){
if(res != 0){
switch(index){
case 0:
result = 'online';
break;
case 1:
result ='iddle';
break;
case 2:
result = 'out';
break;
case 3:
result = 'locked';
break;
default:
result = 'offline';
}
}
});
})
return result;
}
Based on manual from http://redis.io/commands/MULTI multi returns value, which you doesn't return.
In this site but, in spanish I received the right answer. I post here for help to others:
//CHECK USER STATUS ... Take a look at the new parameter 'callback' in the function!
exports.checkUserStatus = function(uid, callback){
redis.multi()
.sismember('users:online',uid)
.sismember('users:iddle', uid)
.sismember('users:out', uid)
.sismember('users:locked', uid)
.exec(function(err, res){
res.forEach(function(res, index){
if(res != 0){
switch(index){
case 0:
// Here invoke the user's function
// and I pass the info
callback('online');
break;
case 1:
callback('online');
break;
case 2:
callback('online');
break;
case 3:
callback('locked');
break;
default:
callback('offline');
}
}
});
})
}
And then I catch the returned value as you will see below:
// sequence of events
// This happend first - #1
checkUserStatus('uid-12343', function(status, user) {
// This happend at the end - #2
// Here we catch the status in asynchronous way
});
// This happend second - #2
console.log("This happend before the redis info arrive!");
Thank you to everyone! I hope I've helped!