Shortcode display CPT Query only showing 1 post?

Question

Ive seen similar questions on here but I am already using WP_Query and wp_reset_postdata.

In short I wrote a shortcode that queries our Custom Post Type to display posts specific to a category. Everything works except the shortcode is only displaying one post when I know there is more.

I know it is something super simple I missed :)

The Query:

function get_gallery_query( $category ){

    $gallery_query = new WP_Query(
        array(
            'post_type'=>'custom_gallery', 
            'posts_per_page'=> '100', 
            'tax_query' => array(
                array(
                    'taxonomy' => 'gallery_category',
                    'field' => 'slug',
                    'terms' => $category
                    )
                )
            )
        );

    if ( $gallery_query->have_posts() ) :

        //the loop
        while($gallery_query->have_posts() ) : $gallery_query->the_post();

        $output = '<article class="masonry-entry" id="post-' . get_the_ID() .'" ' . get_post_class() .' >
                <div class="masonry-thumbnail border">
                    <a href="' . get_post_permalink() . '" title="' . get_the_title() . '" class="inner-shadow">' . get_the_post_thumbnail(get_the_ID(), 'masonry-thumb') .'</a>
                </div><!--.masonry-thumbnail-->

            <div class="masonry-details">
                <h5><a href="' . get_post_permalink() . '" title="' . get_the_title() . '"><span class="masonry-post-title"> ' . get_the_title() .'</span></a></h5>
                <div class="masonry-post-excerpt">
                    ' . getPostLikeLink(get_the_ID()) .'  <p class="post-comment"><a href="' .get_post_permalink() . '"><i class="fa fa-comments qcomment" title="Comments"></i></a> ' . comments_number( ' ', '<sup>1</sup>', '<sup>%</sup>' ) . '</p>' . getBookmarkLink(get_the_ID()) . '
                </div><!--.masonry-post-excerpt-->
            </div><!--/.masonry-entry-details -->  
        </article><!--/.masonry-entry-->';

        endwhile; 

        wp_reset_postdata();

        else :
            $output = 'Sorry, but there are no galleries matching your request';

        endif;

        return $output;


}

Answer 1

As @Milo said in his comment above, you need to use concatenation as this is a loop your in. So you need to add a value each iteration not replace it. Your $output = '' needs to become $output .= ''. Notice the point/dot before declaring the value, in PHP this is used for concatenation.

//the loop
        while($gallery_query->have_posts() ) : $gallery_query->the_post();

        $output .= '<article class="masonry-entry" id="post-' . get_the_ID() .'" ' . get_post_class() .' >
                <div class="masonry-thumbnail border">
                    <a href="' . get_post_permalink() . '" title="' . get_the_title() . '" class="inner-shadow">' . get_the_post_thumbnail(get_the_ID(), 'masonry-thumb') .'</a>
                </div><!--.masonry-thumbnail-->

            <div class="masonry-details">
                <h5><a href="' . get_post_permalink() . '" title="' . get_the_title() . '"><span class="masonry-post-title"> ' . get_the_title() .'</span></a></h5>
                <div class="masonry-post-excerpt">
                    ' . getPostLikeLink(get_the_ID()) .'  <p class="post-comment"><a href="' .get_post_permalink() . '"><i class="fa fa-comments qcomment" title="Comments"></i></a> ' . comments_number( ' ', '<sup>1</sup>', '<sup>%</sup>' ) . '</p>' . getBookmarkLink(get_the_ID()) . '
                </div><!--.masonry-post-excerpt-->
            </div><!--/.masonry-entry-details -->  
        </article><!--/.masonry-entry-->';

        endwhile;