This code isn't working probably, because the connection to mongo isn't established fast enough. So I thought that I have to change it to a asnyc function. But definetly doesn't know where to start. I'm new to Node and Mongo
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It should looks like that, but mongo updates it that every rank is the same digit.
// function for giving rank
function giveRank(arrayArg,resultArg){
// declaring and initilising variables
let rank = 1;
prev_rank = rank;
position = 0;
// displaying the headers in the console
console.log('\n-------OUR RESULTS------\n');
console.log('Name | Mark | Position\n');
// looping through the rank array
for (i = 0; i < arrayArg.length ; i ++) {
/*
If it is the first index, then automatically the position becomes 1.
*/
if(i == 0) {
position = rank;
Ranking.find({name: arrayArg[i]}).then((data) => {
if(data){
updateRank(bla, bla, bla)
}else{
newRank(bla,bla,bla);
}
});
/*
if the value contained in `[i]` is not equal to `[i-1]`, increment the `rank` value and assign it to `position`.
The `prev_rank` is assigned the `rank` value.
*/
} else if(arrayArg[i] != arrayArg[i-1]) {
rank ++;
position = rank;
prev_rank = rank;
Ranking.find({name: arrayArg[i]}).then((data) => {
if(data){
updateRank(bla, bla, bla)
}else{
newRank(bla,bla,bla);
}
});
/*
Otherwise, if the value contained in `[i]` is equal to `[i-1]`,
assign the position the value stored in the `prev_rank` variable then increment the value stored in the `rank` variable.*/
} else {
position = prev_rank;
rank ++;
Ranking.find({name: arrayArg[i]}).then((data) => {
if(data){
updateRank(bla, bla, bla)
}else{
newRank(bla,bla,bla);
}
});
}
}
}
To convert a promise-chain-based asynchronous call into an async/await call, you only need to do a couple things:
Convert the parent function into an async function by using the async keyword, like so: function myFunction (...) {} turns into async function myFunction (...) {}
Use the await keyword in front of your function call, like so: doStuff(...) turns into await doStuff(...)
Convert the parameter to your first .then() callback to the return value of the async call, like so: doStuff().then((data) => {}) turns into let data = await doStuff()
Move the body of the .then() callback below the assignment of the response, like so: doStuff().then((data) => { console.log(data) }) turns into let data = await doStuff(); console.log(data);
So in your example, converting one of the functions would look like so:
async function giveRank(arrayArg,resultArg){
...
...
if(i == 0) {
position = rank;
let data = await Ranking.find({name: arrayArg[i]})
if(data){
updateRank(bla, bla, bla)
}else{
newRank(bla,bla,bla);
}
}
...
...
}