WordPress get same level post id of current post

取同層級頁面id

/**
	取同層級頁面id
	bool $with_parent = true ; 包含父層id
	return array
	
	https://v123.tw
*/
function v123tw_get_same_level_post_id_of_current_post($with_parent=false){
	if(!$id = get_the_ID())return array();
	if($pid = wp_get_post_parent_id( $id ))$id = $pid;
	if(!$id)return array();
	$args = array(
		'post_parent' => $id,
		'order'       => 'ASC',
		'orderby'     => 'menu_order',
		'post_type'   => 'page', 
		'post_status' => 'publish',
	);
	$children_array = get_children($args);
	$rekeyed_array = array_keys($children_array);
	if(!count($rekeyed_array))return array();
	if($with_parent)array_unshift($rekeyed_array,$id);
	return $rekeyed_array;
}

做成簡碼，方便再主題或文章內使用

/**
	取當前頁面之同層級頁面項目
	https://v123.tw
*/
add_shortcode('v123tw-submenu',function(){
	$submenu = v123tw_get_same_level_post_id_of_current_post();
	if($submenu){
		$output = '';
		$output .= '<div class="v123tw_submenu_div">';
		$output .= '<ul>';
		foreach($submenu as $id){
			$output .= '<li><a href="'.get_post_permalink($id).'"><span>'.get_the_title($id).'</span></a></li>'."\n";
		};
		$output .= '</ul>';
		$output .= '</div>';
		echo $output;
	}
});