Can't figure out how to make query checkbox filter

• 

  • ROIBjorn

  • June 11, 2020 at 8:10 pm

  Hello,

  I’m stuck on the following: I’d like to create a filter with the checkbox which I’m using as “category”. I named it ‘trainingscategory’. With this I’d like to filter the posts from my CPT ‘training’. I don’t suppose I’m the first one trying this but I have a hard time finding answers or perhaps I just don’t understand them. I’ve read the query and filter by custom field posts a dozen times but I can’string them together.

  In my functions.php I’ve set:

  <?php
  function my_pre_get_posts( $query ) {
  	// do not modify queries in the admin
  	if( is_admin() ) {	
  		return $query;
  	}
  	
  	// only modify queries for 'training' post type
  	if( isset($query->query_vars['post_type']) && $query->query_vars['post_type'] == 'training' ) {
  		// allow the url to alter the query
  		if( isset($_GET['trainingscategory']) ) {
      		$query->set('meta_key', 'trainingscategory');
  			$query->set('meta_value', $_GET['trainingscategory']);
      	} 
  	}
  	// return
  	return $query;
  }
  add_action('pre_get_posts', 'my_pre_get_posts');

  For now on my page I’m only showing a table with the posts in CPT ‘training’ without the filtering.

  For my sidebar I’d like to show the values set in ‘trainingscategory’.

  <?php
  
  // Load field settings and values.
  $field = get_field_object('trainingscategory');
  $cats = $field['value'];
  
  // Display labels.
  if( $cats ): ?>
  <ul>
      <?php foreach( $cats as $cat ): ?>
          <li><?php echo $field['choices'][ $cat ]; ?></li>
      <?php endforeach; ?>
  </ul>
  <?php endif; ?>

  This doesn’t show anything since this only shows what is set on the current page if I understood correctly. However I couldn’t figure out how to show all values in a list.

  For the filtering I think I’d need to set the above values in a add_query in the URL?
  But then how do I make the table show only the posts with that value?

  I think it should be something like below but I can’t figur out how to make this work as filter result. (I’m using a ul here instead of my table to save space)

  // Query
  		$the_query = new WP_Query(array(
  			'post_type'			=> 'training',
  			'posts_per_page'	=> -1,
  			'meta_key'			=> 'trainingscategory',
  			'orderby'			=> 'meta_value',
  			'order'				=> 'DESC'
  		));
  
  		?>
  		<?php if( $the_query->have_posts() ): ?>
  			<ul>
  			<?php while( $the_query->have_posts() ) : $the_query->the_post();?>
  				<li>
  					<a href="<?php the_permalink(); ?>"><?php the_title(); ?></a>
  				</li>
  			<?php endwhile; ?>
  			</ul>
  		<?php endif; ?>
  
  		<?php wp_reset_query();	 // Restore global post data stomped by the_post(). ?>

  I have a feeling I’ve read the answer a dozen times in the posts but I simply can’t figure it out. If someone could help me in the right direction I’d appreciate that alot.

  Kind regards,