Pfthb

In WordPress I have a right menu with the code:

 <?php wp_list_categories( array(
 'orderby' => 'name',
 'show_count' => false,
 'exclude' => array( 1,2,3,4 )
) ); ?> 

and the query to show posts:

 <?php
 // the query
 $wpb_all_query = new WP_Query(array('post_type'=>'documentos', 'order' => 'ASC', 'post_status'=>'publish'));
 ?>

 <?php if ( $wpb_all_query->have_posts() ) : ?> 
 <h4 class="titDocCat" ><?php single_cat_title(); ?></h4>
 <ul class="doc"> 

 <!-- the loop -->
 <?php while ( $wpb_all_query->have_posts() ) : $wpb_all_query->the_post(); ?>


 <li class="gobierno">
 <div class="kc_col-sm-9 kc_column kc_col-sm-9 noPad">
 <h3 class="titleDoc"><?php the_field('titular_del_documento'); ?></h3>
 <p class="smallDoc"><?php the_field('descripcion_del_documento'); ?></p>
 </div>

 <div class="kc_col-sm-3 kc_column kc_col-sm-3 noPad">
 <a class="btnDownload" href="<?php the_field('archivo'); ?>" download><?php _e( 'Descarga PDF', 'modrox' ); ?></a>
 </div>

 </li>
 <div class="sepGob"></div>
 <?php endwhile; ?>
 <!-- end of the loop -->
</ul>

 <?php wp_reset_postdata(); ?>

 <?php else : ?>
 <p><?php _e( 'Sorry, no posts matched your criteria.', 'modrox' ); ?></p>
 <?php endif; ?>

But when I click a category from the menu, always shows me all posts, from custom post type. How can I do to show only the category selected from the menu

<?php $wpb_all_query = new WP_Query(array('post_type' => 'documentos', 'order' => 'ASC', 'post_status' => 'publish', 'cat_name' => 'category_slug')); ?>

You should have to add "cat_name" parameter in your query and have to pass category slug into it.

You need to modify your query as:

 $pargs = array(
 'post_per_page' => '-1',
 'post_type' => 'documentos',
 'tax_query' => array(
 array(
 'taxonomy' => 'category',
 'field' => 'slug',
 'terms' => $term_slugs
 ),
 'post_status'=>'publish'
 );

$wpb_all_query = new WP_Query($pargs);

Note: $term_slugs is a category slug name.

This is the working code:

<?php
// find last word from URL ( this will basically give you "rings" )
$cat = basename( parse_url( $_SERVER['REQUEST_URI'], PHP_URL_PATH ) );

// the query
$args = array(
 'post_type' => 'documentos',
 'posts_per_page' => -1,
 'orderby' => 'DATE',
 'order' => 'ASC',
 'tax_query' => array(
 array(
 'taxonomy' => 'category',
 'field' => 'slug',
 'terms' => esc_attr( $cat ),
 ),
 ),
);

// query results
$the_query = new WP_Query( $args );

// display results
if ( $the_query->have_posts() ) 
 while ( $the_query->have_posts() ) 
 $the_query->the_post();
 echo '<h2>' . get_the_title() . '</h2>';
 
 // reset post
 wp_reset_postdata();

?>

Reference link