Already was resolve my problem and the cause is because the component was created dinamically, the solution is use .on(“change”, instead .change(function().
I share the code of Ján Bočínec with the modification to use three dropdownlist or more.
//Parent child con ajax
function parent_child_cat_select() { ?>
<script type="text/javascript">
/* <![CDATA[ */
jQuery(document).ready(function() {
//segundo drop down
jQuery('#sub_cat_div').on('change','#parent_grado',function(){
var parentCat=jQuery('#parent_grado').val();
// call ajax
jQuery.ajax({
url:'/dentrorealdelvalle/wp-admin/admin-ajax.php',
type:'POST',
data:'action=category_select_action&nameid=parent_grupo&parent_cat_ID=' + parentCat,
success:function(results)
{
jQuery("#sub_grupo_div").html(results);
}
})
});
//primer drop down
jQuery('#parent_cat').change(function(){
var parentCat=jQuery('#parent_cat').val();
// call ajax
jQuery.ajax({
url:'/dentrorealdelvalle/wp-admin/admin-ajax.php',
type:'POST',
data:'action=category_select_action&nameid=parent_grado&parent_cat_ID=' + parentCat,
success:function(results)
{
jQuery("#sub_cat_div").html(results);
}
})
});
});
/* ]]> */
</script>
<form action="<?php bloginfo('url'); ?>/" method="get">
<div id="parent_cat_div"><?php
$terms=get_terms('grupos',
array(
'hide_empty' => false,
'parent' => 0,
)
);
$datosparent="";
echo '<select id="parent_cat" name="escuelas">';
// Get categories as array
echo '<option disabled selected value> -- Seleccione Escuela -- </option>';
foreach ( $terms as $term ) :
echo '<option value="' . $term->term_id . '">' . $term->name . '</option>';
$datosparent=$datosparent . ',' . $term->term_id;
endforeach;
echo '</select>';
?></div>
<div id="sub_cat_div"><select class="ramiro" name="sub_cat_disabled" id="parent_grado" disabled="disabled"><option>Seleccione grado!</option></select></div>
<div id="sub_grupo_div"><select class="ramiro" name="sub_grupo_disabled" id="parent_grupo" disabled="disabled"><option>Seleccione grupo!</option></select></div>
<div id="submit_div"><input type="submit" value="View" /></div>
</form>
<?php }
function implement_ajax() {
$parent_cat_ID = $_POST['parent_cat_ID'];
$nameid = $_POST['nameid'];
if ( isset($parent_cat_ID) )
{
$terms=get_terms('grupos',
array(
'hide_empty' => false,
'parent' => $parent_cat_ID,
)
);
if ( $terms ) {
echo '<select id="' . $nameid . '" name="grado">';
// Get categories as array
echo '<option disabled selected value> -- Seleccione Grado -- </option>';
foreach ( $terms as $term ) :
echo '<option value="' . $term->term_id . '">' . $term->name . '</option>';
endforeach;
echo '</select>';
} else {
?><select name="sub_cat_disabled" id="sub_cat_disabled" disabled="disabled"><option>No child categories!</option></select><?php
}
die();
} // end if
}
add_action('wp_ajax_category_select_action', 'implement_ajax');
add_action('wp_ajax_nopriv_category_select_action', 'implement_ajax');//for users that are not logged in.