Push object into local array from asynchronous callback function
12,044
Solution 1
there are different ways,
the easiest way would be creating calling the async function one after another, as follows
var Characters = [];
var objectKeys = Object.keys(Connections);
var ID = 0;
if (ID < objectKeys.length)
doCall(objectKeys[ID]);
else
console.log(Characters);
function doCall(key) {
redis_client.HGETALL(key, function(err, result) {
if (result) {
Characters.push(result);
}
ID++;
if ( ID < objectKeys.length)
doCall(objectKeys[ID]);
else
console.log(Characters);
});
}
Solution 2
Regular for loop doesn't work correctly when you have async call and global variables. Here is a loop version that would work (make sure async is installed. if not do "npm install async"):
var async = require('async');
var Characters = [];
async.each(Connections, function(ID, callback) {
redis_client.HGETALL(ID, function(err, result) {
if (result) {
Characters.push(result);
}
callback(null);
});
}, function(err) { // this function gets called when the loop is done
console.log("finish:");
// print out your array
for (var i = 0, len = Characters.length; i < len; i++) {
console.log(Characters[i]);
}
});
Author by
James07
Updated on June 04, 2022Comments
-
James07 almost 2 years
I use node.js on my server and I use redis key-store for storing data about my characters. Every connection has it own character. I want to get all data about characters(Person, has its name, age, profession, ...) into Characters array, so I can then selectively send it to connected clients.
var Characters = []; for (var ID in Connections) { redis_client.HGETALL(ID, function(err, result) { if (result) { Characters.push(result); } }); } console.log(Characters);
I have read, that this is due to asynchronous vs synchronous problem, so I made global variable character.
//global variables var character; //function code var Characters = []; for (var ID in Connections) { redis_client.HGETALL(ID, function(err, result) { character = result; }); if(character) { console.log(character); // returns correct result // make copy of character Characters.push(JSON.parse(JSON.stringify(character))); character = undefined; } } console.log(Characters); // array of 1 character * number of connection //BUT I expect different character for each connection