Show all posts from the tags without having to set all of them

Question

I created the tag.php page and when I click on a tag on the page of a post it takes me to the tag.php page with the URL of the tag, for example: / tag / wordpress-1 /.

I want to show all the posts of a the tags without having to set all of them.

'tag' => 'post_tag' did not work, it shows nothing on the page.

But when I set the tag. For example 'tag' => 'wordpress-1' it shows all posts with this tag, but I do not want to have to set all tags, I want it to be automatic.

<?php $paged = (get_query_var('paged')) ? get_query_var('paged') : 1;
    $args = array( 'post_type' => 'post', 'posts_per_page' => 9, 'paged' => $paged, 'tag' => 'post_tag' );
    $wp_query = new WP_Query($args);
    while ( have_posts() ) : the_post(); ?>
       <div class="noticia-index">
          <a href="<?php the_permalink(); ?>">
          <?php $backgroundImg = wp_get_attachment_image_src( get_post_thumbnail_id($post->ID), 'full' );?>
          <div class="post-thumbnail" style="background: url('<?php echo $backgroundImg[0]; ?>'); background-size: cover; background-position: center;">
          </div></a>
          <div class="noticia-index-conteudo"><a href="<?php the_permalink(); ?>"><h2 class="noticia-titulo"><?php the_title(); ?></h2></a>
          <div class="subtitulo-noticia"><?php the_excerpt(); ?></div>
          <span><img src="<?php echo get_stylesheet_directory_uri(); ?>/img/icones/calendar1.svg" class="calendar"></span>
          <span class="date"><?php echo get_the_date(); ?></span>
          <span><img src="<?php echo get_stylesheet_directory_uri(); ?>/img/icones/clock1.svg" class="clock"></span>
          <span class="time"><?php the_time(); ?></span>
          <span><img src="<?php echo get_stylesheet_directory_uri(); ?>/img/icones/bubble2.png" class="bubble"></span>
          <span class="disqus-comment-count comments" data-disqus-url="<?php the_permalink(); ?>#disqus_thread"></span>
          <a class="leia-mais" href="<?php the_permalink(); ?> ">Leia mais...</a>
         </div>
       </div>

        <?php endwhile; ?>

        <!-- Links de paginação -->
        <?php echo paginate_links( array(

            'prev_text' => '<span>Anterior</span>',
            'next_text' => '<span>Próxima</span>'

        ));
?>

Answer 1

WP default loop will automatically show the posts with in current tag on tag.php page. you dont need to set custom WP_Query for that but make sure that you are not modifying the loop from any other method.

if( have_posts() ) : while( have_posts() ) : the_post();

   the_title();
  //Rest of code.

endwhile;
endif;

Answer 2

But I want it to show a specific number of posts and have pagination. How I do without the custom WP_Query?

if you want to have a different number of posts per page, other than set under 'settings - reading - blog pages show at most [] posts', try working with a 'pre_get_posts' action (remove your custom query);

example code:

function wpse_254946_tag_query( $query ) {
    if ( is_admin() || ! $query->is_main_query() )
        return;

    if ( is_tag() ) {
        // Display certain number of posts per page for tag archives
        $query->set( 'posts_per_page', 9 );
        return;
    }
}
add_action( 'pre_get_posts', 'wpse_254946_tag_query', 1 );

your existing pagination function should work with that.