I have been developing in PHP for many years and now I´m trying to learn NodeJS, and I´m having problems with asynchronous functions...
I have this function in NodeJS (source is an array of users):
//userformat.js
var age = module.exports.age = function(date){
var diff = new Date - new Date(date);
var diffdays = diff / 1000 / (60 * 60 * 24);
var age = Math.floor(diffdays / 365.25);
return age;
}
...etc.
//index.js
function format(source, me, callback){
var len = source.length
for (var i = 0; i < len; i++){
source[i]['_age'] = userFormat.age(source[i]['birthday']);
source[i]['_rating'] = userFormat.rating(source[i]['votes']);
source[i]['_is_followed'] = userFormat.followed(source[i]['fllws'], me);
}
callback(null, source);
}
I know that function is wrong in Node, because is possible that the function calls the callback before the functions in the for() had finished, and the values in the array could be undefined, for this reason I changed the function using callbacks:
//userformat.js
var age = module.exports.age = function(date, callback){
var diff = new Date - new Date(date);
var diffdays = diff / 1000 / (60 * 60 * 24);
var age = Math.floor(diffdays / 365.25);
callback(age);
}
...etc.
//index.js
function format(source, me, callback){
var len = source.length
for (var i = 0; i < len; i++){
userFormat.age(source[i]['birthday'], function(resul){
source[i]['_age'] = resul;
userFormat.rating(source[i]['votes'], function(resul){
source[i]['_rating'] = resul;
userFormat.followed(source[i]['fllws'], me, function(resul){
source[i]['_is_followed'] = resul;
//Callback
if (i == len-1){
callback(null, source);
}
})
})
})
}
}
That is correct? I have another way to do it more efficient or elegant?
Thank you so much!
