Question

This function is called on onkeydown of textbox

function autoComplete(type, select) {
    $('#search_name').autocomplete({
    source: function( request, response ) {
        $.ajax({
        url: "/searches/autoComplete",
        dataType: "json",
        data: {
            term: $.trim(request.term)
        },
        success: function( data ) {
            response( $.map( data, function( item ) {
            return {
                label: item.value,
                value: item.value,
                type : item.type,
                id   : item.id
            }
            }));
        }
        });
    },
    minLength: 2,
    select: function( event, ui ) {
        var url = ui.item.type + '/edit/' + ui.item.id;
        $(location).attr('href', url);
    }
    });

}

When checked in console gets an error as below

a is null

..."resolve"],fail:[b,"reject"],progress:[c,"notify"]},function(a,b){var c=b[0],e=b...

This error will comes only when no response data is returned, otherwise it is working fine.

How to avoid this error?

Answer 1

If you are expecting a request to return data, but it’s returning null, then that should not be treated as a success but as a failure. In your server code you should return 404 or something like that if you can’t return the requested data.

Edit: From comments below, seems this was best solved using header("HTTP/1.0 404 Not Found"); in PHP.

I guess you could also just check in the JavaScript to avoid the error, but that isn’t really a clean solution..

success: function( data ) {
    if(data) {
        response( $.map( data, function( item ) {
            return {
                label: item.value,
                value: item.value,
                type : item.type,
                id   : item.id
            }
        }));
    }
}