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Redis – Array is empty, no data after for loop added

I’m using redis and nodejs for the first time, without success. Trying to loop insert data but got an empty array.

const redis = require("redis");

const client = redis.createClient({
  retry_strategy: function(options) {
    if (options.error && options.error.code === "ECONNREFUSED") {
      // End reconnecting on a specific error and flush all commands with
      // a individual error
      return new Error("The server refused the connection");
    }
    if (options.total_retry_time > 1000 * 60 * 60) {
      // End reconnecting after a specific timeout and flush all commands
      // with a individual error
      return new Error("Retry time exhausted");
    }
    if (options.attempt > 10) {
      // End reconnecting with built in error
      return undefined;
    }
    // reconnect after
    return Math.min(options.attempt * 100, 3000);
  },
});

var data_value = {
        id: '235235',
        totalrv: 'WAIT',
        product: 'productName2',
        url: 'url2',
        process: 'proc',
        task: 'msg'
    };

client.set("key0", JSON.stringify(data_value));
client.set("key1", JSON.stringify(data_value));
client.set("key2", JSON.stringify(data_value));
client.set("key3", JSON.stringify(data_value));
client.set("key4", JSON.stringify(data_value));

//client.get("key2", redis.print);

var logger_data = {
        logger: []
    };

client.keys('*', function (err, keys) {
    if (err) return console.log(err);

    for(var i = 0, len = keys.length; i < len; i++) {
        var values_v = client.get(keys[i].toString(), function(err, val) {
            // console.log(logger_data);
            // data is exist ...
            logger_data.logger.push(JSON.parse(val));
        });
    }
});

// empty data
console.log(logger_data);

I wrote 2 print data result, in the loop it’s working ok, but end of function, there are no data in array.

Tags:

2

Answers


  1. Chosen as BEST ANSWER
    0

    Ok, with help of CertainPerformance, it's now working in asynchronous. Thank you very much ...

    async function getMessage () {
    var logger_data = {
        logger: []
    };

    return new Promise(function(resolve, reject) {
        client.keys('*', function (err, keys) {
            if (err) return console.log(err);

            for(var i = 0, len = keys.length; i < len; i++) {
                var values_v = client.get(keys[i].toString(), function(err, val) {
                    logger_data.logger.push(JSON.parse(val));
                    resolve(logger_data);
                });
            }
        });
    });
}

async function main() {
    let message = await getMessage();
    console.log(message);
}

main();

  2. 0

    you can call a function inside the callback if you want to print the logger_data with values outside the asynchronous callback, like this

    function printLoggerData(){
 console.log(logger_data);
}

client.keys('*', function (err, keys) {
    if (err) return console.log(err);

    for(var i = 0, len = keys.length; i < len; i++) {
        var values_v = client.get(keys[i].toString(), function(err, val) {
            // console.log(logger_data);
            // data is exist ...
            logger_data.logger.push(JSON.parse(val));
            // calling the function here so that it contains the latest values
            printLoggerData(); 
       });
    }
});
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