Javascript: function in function and return

Question

I have ajax function in custom function and I need to call my custom function and get some variable from the ajax function. Why this is not possible?

1st idea:

<script>
    function getValue(){

        $.nette.ajax({
            url: "http://example.com/request",
            contentType: 'application/json',
            dataType: 'json',
            success: function(payload) {
                console.log(payload.value); // contains RIGHT value
                return payload.value;
            }
        });
    }

    var try = getValue();
    console.log(try); // = undefined
</script>

2nd idea:

<script>
    function getValue(){
        var returning = "";

        $.nette.ajax({
            url: "http://example.com/request",
            contentType: 'application/json',
            dataType: 'json',
            success: function(payload) {
                returning = payload.value;
                console.log(payload.value); // contains RIGHT value
            }
        });
            console.log(returning); // = ""
    }

</script>

`console.log(returning)` is being executed *before* your asynchronous call has finished. — Adam Konieska, May 12 '16 at 14:24

score 2 · Accepted Answer · answered May 12 '16 at 14:37

ajax is a promise. use a callback to do something when the request was successful

function getValue(callback){
    $.nette.ajax({
        url: "http://example.com/request",
        contentType: 'application/json',
        dataType: 'json',
        success: function(payload) {
            callback(playload);
        }
    });
}

Javascript: function in function and return

1 Answers1