How to add class on wp_list_pages children - wordpress

Question

I' am using bootstrap 3. I' don't know if its possible in WordPress to add the class on function wp_list_pages on its children ul. I know it possible with jQuery.
This is what I currently have
<ul class="nav navbar-nav dropdown" role="menu" aria-labelledby="dLabel">
<?php
$args = array(
'authors' => '',
'child_of' => 0,
'date_format' => get_option('date_format'),
'depth' => 2,
'echo' => 1,
'exclude' => '5, 141, 143, 145',
'include' => '',
'link_after' => '',
'link_before' => '',
'post_type' => 'page',
'post_status' => 'publish',
'show_date' => '',
'sort_column' => 'menu_order',
'title_li' => '',
'walker' => ''
);
?>
<?php wp_list_pages( $args ); ?>
</ul>
This is a dropdown menu, so WordPress adds a class children into its ul, but can I add bootstrap class dropdown into that children ul.

Answer 1

You need to create a custom walker to change the child <ul> class. There's no filter inside the default page walker to change the classes that are applied.
You don't need to include so many arguments for wp_list_pages by the way. Only the ones you change.
Here's how I'd do it:
Add to functions.php -
class WPSE_Walker_Page extends Walker_Page {
/**
* #see Walker::start_lvl()
* #since 2.1.0
*
* #param string $output Passed by reference. Used to append additional content.
* #param int $depth Depth of page. Used for padding.
* #param array $args
*/
function start_lvl( &$output, $depth = 0, $args = array() ) {
$indent = str_repeat("\t", $depth);
$output .= "\n$indent<ul class='change-me children'>\n"; // MAKE SURE TO CHANGE CLASSES HERE
}
}
Then replace your existing call to wp_list_pages() with:
<?php
$args = array(
'depth' => 2,
'exclude' => '5, 141, 143, 145',
'sort_column' => 'menu_order',
'title_li' => '',
'walker' => new WPSE_Walker_Page(),
);
wp_list_pages( $args ); ?>

Answer 2

Okay, still didn't find what I was looking for but I found a work around without using jQuery only had to paste in the code of class dropdown-menu into my css style, thats it. Works!
CSS
.primary-menu-container > ul > li.page_item_has_children > ul.children{
position: absolute;
top: 100%;
left: 0;
z-index: 1000;
display: none;
float: left;
min-width: 160px;
padding: 5px 0;
margin: 2px 0 0;
list-style: none;
font-size: 14px;
background-color: #fff;
border: 1px solid #ccc;
border: 1px solid rgba(0,0,0,.15);
border-radius: 4px;
-webkit-box-shadow: 0 6px 12px rgba(0,0,0,.175);
box-shadow: 0 6px 12px rgba(0,0,0,.175);
background-clip: padding-box;
}