how to wait till the response is received from redis in node?

I am new to node and redis.I am using redis in my node application.I want to retreive
data from redis in a synchronous fashion.Here is what I tried.

var redis = require("redis"),
client = redis.createClient();

client.set('key',10,redis.print);

function getfn1(key){
client.get(key,function(err,reply){
if(err){
console.log('Response from getfn1:-');
console.log(err);
return;
}
console.log('Response from getfn1:-');
console.log(reply);
});
}

async function getfn2(key){
let response = await client.get(key);
console.log('Response from getfn2:-');
console.log(response);
}
console.log('1');
getfn1('key');
console.log('2');
getfn2('key');
console.log('3');


The result is as follows:

1
2
3
Response from getfn2:-
false
Response from getfn1:-
10


As you can see I am trying to wait for the result from redis using async and await in getfn2() but I get a response of 'false' instead of the original response of 10.It would be better if you suggested a method of waiting for data from redis.

1 Answer
1

The async/await syntax is meant to be used with Promises, but the redis module does not return Promises by default.

async/await

If you want to use Promises, this is what the documentation says to do:

You can also use node_redis with promises by promisifying node_redis
with bluebird as in:

var redis = require('redis');
bluebird.promisifyAll(redis.RedisClient.prototype);
bluebird.promisifyAll(redis.Multi.prototype);


It'll add a Async to all
node_redis functions (e.g. return client.getAsync().then())

// We expect a value 'foo': 'bar' to be present
// So instead of writing client.get('foo', cb); you have to write:
return client.getAsync('foo').then(function(res) {
console.log(res); // => 'bar'
});


Your getfn2 function would then become:

getfn2

async function getfn2(key){
let response = await client.getAsync(key);
console.log('Response from getfn2:-');
console.log(response);
}


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