Asynchronous Javascript Issue

I'm trying to make a function details() that looks up the details of certain events (getdetails) based on the available events. In the example below, details are asked for the even

Solution 1:

One way is to use the async library, in particular the async.each or async.eachSeries function. (You could use async.map, but in your case you are actually not mapping, but modifying the underlying array items directly.)

In particular, your code would look like this:

async.each(res.Data, function(val,callback){
    getdetails(val.ID).then(function(data){
        tmp = JSON.parse(data);
        Object.keys(tmp.Data[0]).map(function(v,j){
            val[v] = tmp.Data[0][v];
        });
        callback(null); // Asynchronous code has finished without error
    }, function(error){ //error callbackcallback(error); // Asynchronous code has finished with error
    });
}, function(error) {
    // All asynchronous calls have finishedif(error)
        console.log("Error", error);
    elseconsole.log("Success", res);
});

async.each will run many iterations at the same time, while async.eachSeries will run only one iteration at the same time.

Solution 2:

Well you already use promise - see then in your code and if it's angular then then itself return deferred promise so you can do:

res.Data.map(function (val, i) {
    getdetails(val.ID).then(function (data) {
        tmp = JSON.parse(data);
        Object.keys(tmp.Data[0]).map(function (v, j) {
            val[v] = tmp.Data[0][v];
        });
    }, function (error) { //error callbackconsole.log(error)
    }).then(function () {
        console.log(JSON.stringify(res));
    })
});

EDIT: inject service $q into your controller or service

promises = [];
res.Data.map(function (val) {
    promises.push(getdetails(val.ID).then(function (data) {
        tmp = JSON.parse(data);
        Object.keys(tmp.Data[0]).map(function (v, j) {
            val[v] = tmp.Data[0][v];
        });
    }, function (error) { //error callbackconsole.log(error)
    }));
});
$q.all(promises).then(function () {
    console.log(JSON.stringify(res));
});

now when all the getdetails are resolved you can console.log or do whatever you want with the data