Question

I am using a jQuery method $.getJSON to update data in some cascading drop down lists, in particular, a default value if there is nothing returned for the drop down, e.g. “NONE”.

I just want some clarification to how my logic should go.

var hasItems = false; 
$.getJSON('ajax/test.json', function(data) {
hasItems = true;

    //Remove all items
    //Fill drop down with data from JSON


});

if (!hasItems)
{
    //Remove all items
    //Fill drop down with default value
}

But I don’t think this is right. So do I enter into the function whether or not I receive data? I guess I really want to check the data object contains something – to set my boolean hasItems.

Answer 1

You should handle the check right inside the callback function, check the example here.

var hasItems = false; 
$.getJSON('ajax/test.json', function(data) {
hasItems = true;

    //Remove all items
    //Fill drop down with data from JSON
if (!hasItems)
{
    //Remove all items
    //Fill drop down with default value
}

});