Filter posts by multiple checkbox categories

Question

I would like to set up a widget to filter my post by categories. Let's say, I do have two different categories, "Countries" and "length of stay" with sub categories. Here is an example of what I have:

• Countries

  • China
  • Laos
  • Vietnam

• Length of stay

  • 2-4 Days
  • 5-7 Days
  • 8-10 Days

What I want, is to filter posts by multiple categories. So, If the user is checking the country "Laos" and a length of stay of "2-4Days", I would like to retrieve only posts where the category "Laos" AND the category "2-4Days" has been attached.

I tried to use the Query Multiple Taxonomies pluging. However, this plugging is retrieving all posts with the "Laos" category and all posts with the length of stay of "2-4Days".

I know, that I can filter post with this query, but, I need some help to create this widget with the submit button. Also, I would like to customise it to remove parent categories and display them as a title (remove the checkbox of "Countries" and "Length of stay" and add to them a specific class)?

Working query:

<?php
// cat 42=Laos      cat 57=2-4Days
$my_query_1 = new WP_Query(
    array(
        'category__and' => array(42,57)
    )
);
while ($my_query_1->have_posts()) {
    $my_query_1->the_post();
    ?>
    <a href="<?php the_permalink() ?>" rel="bookmark" title="Permanent Link to <?php the_title(); ?>">
        <?php the_title(); ?><?php the_excerpt(); ?>
    </a>
    <?php
}

Thanks for helping

Answer 1

I thing, you should use this code for filter the check box category

<?php // cat 42=Laos      cat 57=2-4Days
    <?php $my_query_1 = new WP_query(array('category__and' => array(42,57))); ?>
    <?php while ($my_query_1->have_posts()) : $my_query_1->the_post(); ?>
    <a href="<?php the_permalink() ?>" rel="bookmark" title="Permanent Link to
    <?php the_title(); ?>"><?php the_title(); ?><?php the_excerpt(); ?></a>
    <?php endwhile; ?>