Memcached Question posted in
A decent usage manual can be found here.

return result from memcached.get()?

I am using npm memcached package https://www.npmjs.com/package/memcached

It is possible to return data from memcached get method?
Now return data is undefined/

memcached.set('foo', 'bar', 10, function (err) { });

let data1;
memcached.get('foo', function (err, data) {
    console.log(data); // bar
    data1 = data
});
console.log(data1); // undefined

let data2 = memcached.get('foo', function (err, data) {
    console.log(data); // undefined
    return data;
});
console.log(data2); // undefined


let data3 = async () => {
    let result = await memcached.get('foo', function (err, data) {
        console.log(data); // bar
    });
    console.log(result); // undefined
    return result;
}
console.log(data); // {}
Tags:

2

Answers


  1. 0

    You can’t return from get() as it’s an asynchronous callback. What you can do is:

    with callbacks: 

    memcached.get('foo',(err, data) => {
  if(err) {
    console.log('error: ', err);
  } else {
    console.log('data: ', data);
  }
});

    with promises:

    memcached.get('foo')
    .then((data) => {
        console.log('data: ', data);
    })
    .catch((err) => {
        console.log('error: ', err);
    });

    and with async/await:

    const getData = async () => {
    try {
        const data = await memcached.get('foo');
        console.log('data: ', data);
    } catch (err) {
        console.log('error: ', err);
    }
}

    hope this helps 🙂

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  2. 0

    Since memcached is async you can’t really return from it, altho I see OP found a way via a promisify wrapper. What you can do is call another function from inside the callback.
    Working with async socket communication I’ve had to split up a lot of my workflows into request and receives.

    
memcached.get('foo',(err, data) => {
  doStuff(data);
});

function doStuff(data) {
//do some stuff here
}

    Of course you could always do your work with the data inside the handler too. But in some cases that isnt the best approach.

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