Widget instance options not showing correctly

Question

i have a setup like

function form($instance) {
    $defaults = array(
        'title' => 'Recent Products',
        'number_products' => 3
    );
    $instance = wp_parse_args($instance, $defaults);

but my title is ok but number_products always does not show. i debuged in netbeans and found that form() is run 2 times and 1st time, variables look like

$instance = array(0)
// after wp_parse_args, 
$instance = array('title' => 'Recent Products', 'number_products' => 3);

on 2nd run of wp_parse_args, i dont know why it runs the 2nd time,

$instance = array('title' => 'Recent Products', 'number_products' => null);
// after wp_parse_args
$instance = array('title' => 'Recent Products', 'number_products' => null);

i dont really know whats happening ... can some1 enlighten me?

Answer 1

i finally found the answer, its actually not a problem with the code i posted. its in the update() function. i have some validation code

function update($new_instance, $old_instance) {
    $instance['title'] = esc_attr(strip_tags($new_instance['title']));
    if (is_int($new_instance['number_products'])) {
        if ($new_instance['number_products'] > 0)
            $instance['number_products'] = $new_instance['number_products'];
        else
            $instance['number_products'] = 1;
    } else {
        $instance['number_products'] = $old_instance['number_product'];
    }

    return $instance;
}

the problem is at 2 places. i should be using is_numeric over is_int, the reason is

To test if a variable is a number or a numeric string (such as form input, which is always a string), you must use is_numeric().

then, in the else, $old_instance['number_product'] should have be plural $old_instance['number_products']

Answer 2

I am not sure about two runs either. Had you tried just dumping content inside function instead of debug? Something like this:

function form( $instance ) {

    var_dump( $instance );

    $defaults = array(
        'title' => 'Recent Products',
        'number_products' => 3
    );
    $instance = wp_parse_args($instance, $defaults);

    var_dump( $instance );