Node.js request method callback [duplicate]

Question

This question already has answers here:

How do I return the response from an asynchronous call? (44 answers)

JavaScript: what's the difference between a function name & function reference? (5 answers)

Closed 9 years ago.

client.get method does not work in redis for node.js

//blog function
module.exports = {
 index: function () {
 var data = new Object();
 data.ip = base.ip();
 var redis = require("redis");
 var client = redis.createClient(6379,'192.168.33.10');
 client.get("foo",function(err,reply,callback)
 {
 var x=reply.toString();
 });
 data.y=x;
 return data;
 }
};

data.y="bar" expects but

x is not defined.

where is the problem?

• Spartan Troy: I can't understand it the link that you gave
• Arif Khan: @dm03514 is right, you need to understand javascript nature that is asynchronous

Answer 1

Your problem is that client.get is an asynchronous method, which you can't return from. You need some sort of asynchronous control flow, such as callbacks.

//blog function
module.exports = {
 index: function (callback) {
 var data = new Object();
 data.ip = base.ip();
 var redis = require("redis");
 var client = redis.createClient(6379, '192.168.33.10');
 client.get("foo",function(err,reply) {
 if(err) return callback(err);
 data.y = reply.toString();
 callback(null, data);
 });
 }
};

You'd then use it like

var obj = require('./whatever');
obj.index(function(err, result) {
 //result will contain your data.
});