How to get all posts in selected taxonimies custom post type?

Question

I have a post type called 'faq' and taxonomy called 'type' within my template and a few taxonomy terms created "Design", "Print", "Display" etc.

The idea I am trying to implement is to display only the posts that belong to assigned taxonomies (types) without duplication. Each post may be assigned to multiple taxonomies (types).

My current code works fine as long as the post have got only one taxonomy assigned to it. As soon as I assign more then one taxonomy it shows duplicate posts like this:

• Question 6
• Question 5
• Question 1
• Question 1

Here is my current code:

                        <?php

                        $post_type = 'faq';
                        $tax = 'type';
                        $faq_types = get_field('types');

                        $filtered = array();

                        $termargs = array( 'include' => $faq_types );
                        $tax_terms = get_terms($tax, $termargs);

                        if ($tax_terms) {
                          $i = 1;
                          foreach ($tax_terms as $tax_term) {

                            $args=array(
                              'post_type' => $post_type,
                              $tax => $tax_term->slug,
                              'post_status' => 'publish',
                              'posts_per_page' => -1,
                              'caller_get_posts'=> 1
                            );

                            $my_query = null;
                            $my_query = new WP_Query($args);

                            if( $my_query->have_posts() ) {

                              while ($my_query->have_posts()) : $my_query->the_post(); ?>

                                <div class="accordion-section">
                                    <a class="accordion-section-title" href="#accordion-<?php echo $i; ?>"><i class="fa fa-chevron-right"></i> <?php the_title(); ?></a>

                                    <div id="accordion-<?php echo $i; ?>" class="accordion-section-content">
                                        <?php the_content(); ?>
                                    </div>
                                </div>

                                <?php
                              $i++;    
                              endwhile;
                            }
                            wp_reset_query();

                          }
                        }

                        ?>

I'd really appreciate any help with getting this working the way I need.

Answer 1

Your current loop is saying "For each taxonomy term, show all posts associated with that term", so of course it will duplicate if there is one post associated with multiple terms. Take your query out of the foreach loop and use a single tax query with an array of terms:

$args = array(
    'post_type' => $post_type,
    'tax_query' => array(
        array(
            'taxonomy' => $tax,
            'field'    => 'slug',
            'terms'    => $term_slugs,
        ),
    ),
    'post_status' => 'publish',
    'posts_per_page' => -1,
    'caller_get_posts'=> 1
);

EDIT

By the way, you'll need to convert your array of term objects to an array of term slugs for this to work properly:

$term_slugs = array();
foreach( $tax_terms as $term ) {
    $terms_slugs[] = $term->slug; 
}