AJAX callback doesn't return data....as expected

Question

I used this example to hopefully return data after an AJAX call. Basically I execute the AJAX calling a callback function that process and returns the desired final data. However, when I execute the code the variable assigned to get the data is undefined and the callback function is correctly executed AFTER....

This is the function that executes the AJAX call:

    function getgraphdata(callback){
    $.ajax({
        type: "GET",
        url: "DiCAST_hourly.csv",
        dataType: "text",
        async: false,
        success: callback,
        error: function(){alert("Error")}
        });
};

This is the callback function:

function processgraphData(allText) {
    var result = [];
    var allTextLines = allText.split(/\r\n|\n/);
    for (var i=1; i<allTextLines.length; i++) {
        if (allTextLines[i].split(",")[0] == 'LETO') {
            var line = allTextLines[i].split(",");
            for (var j = 1; j<line.length - 5; j += 5){
                result.push([line[j],line[j+1],line[j+2]]);
            };
            break;
            };
        };
    console.log("OK");
    console.log(result);
    return result;
    };

These are the lines where I execute this code:

      console.log("OKOK");
      var result = getgraphdata(processgraphData);
      console.log(result);
      console.log("OKOK");

And this is what the browser returns:

 OKOK getinfo.js:135
 OK getinfo.js:86
[Array[3], Array[3], Array[3], Array[3], Array[3], Array[3], Array[3], Array[3], Array[3], Array[3], Array[3], Array[3], Array[3], Array[3], Array[3], Array[3], Array[3], Array[3], Array[3], Array[3], Array[3], Array[3], Array[3], Array[3], Array[3], Array[3], Array[3], Array[3], Array[3], Array[3], Array[3], Array[3], Array[3], Array[3], Array[3], Array[3], Array[3], Array[3], Array[3], Array[3], Array[3], Array[3], Array[3], Array[3], Array[3], Array[3], Array[3], Array[3], Array[3], Array[3], Array[3], Array[3], Array[3], Array[3], Array[3], Array[3], Array[3], Array[3], Array[3], Array[3], Array[3], Array[3], Array[3], Array[3], Array[3], Array[3], Array[3], Array[3], Array[3], Array[3], Array[3], Array[3], Array[3]] getinfo.js:87
undefined getinfo.js:137
OKOK

try using: success: function(response) { callback(response); } — Suchit kumar, Dec 11 '14 at 11:51

score 0 · Accepted Answer · edited Dec 11 '14 at 12:44

0

This would resolve your issues:

function getgraphdata(callback){
    var theresponse;
    $.ajax({
        type: "GET",
        url: "DiCAST_hourly.csv",
        dataType: "text",
        async: false,
        success:function(response){     
        theresponse = processgraphData(response);
        },
        error: function(){alert("Error")}
        });
    return theresponse;

edited Dec 11 '14 at 12:44

Rafa

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answered Dec 11 '14 at 12:00

Suchit kumar

11,809
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Sorry, but this is not resolving the issue. Thanks – Rafa Dec 11 '14 at 12:03
add async:false and try. – Suchit kumar Dec 11 '14 at 12:05
Still not getting the data, but I now think the problem is where I do the assigment: var result = getgraphdata(processgraphData); – Rafa Dec 11 '14 at 12:12
glad you got the reason. – Suchit kumar Dec 11 '14 at 12:13
With async: false, I make sure I execute the callback BEFORE doing the assignment, however, I still don't get the data into the final variable... estrange. – Rafa Dec 11 '14 at 12:17
how you are doing the assignment. can you show that part. – Suchit kumar Dec 11 '14 at 12:20
I edited the post, as you can see I execute the callback function but the array generated is not returned by getgraphdata – Rafa Dec 11 '14 at 12:26
Let us [continue this discussion in chat](http://chat.stackoverflow.com/rooms/66654/discussion-between-rafa-and-suchit). – Rafa Dec 11 '14 at 12:36

AJAX callback doesn't return data....as expected

1 Answers1