functions.php

<?php require_once('wp-bootstrap-navwalker.php');
    
function theme_setup(){
    add_theme_support('post-thumbnails');
  
    //Nav Menus
    register_nav_menus(array(
    'primary' => __('Primary Menu')
    ));
    register_nav_menus(array(
    'footer' => __('Footer Menu')
    ));
}

add_action('after_setup_theme', 'theme_setup');

  // Filter the except length
  function wpdocs_custom_excerpt_length() {
    return 50;
  }
  add_filter( 'excerpt_length', 'wpdocs_custom_excerpt_length');
  
  // Filter the excerpt "read more" string.
  function wpdocs_excerpt_more( $more ) {
      return ' [...]';
  }
  add_filter( 'excerpt_more', 'wpdocs_excerpt_more' );

  // Filter the excerpt "read more" link.
  function new_excerpt_more($output) {
      return $output . '<p><a href="'. get_permalink() . '">' . 'weiter lesen...' . '</a></p>';
  }
  add_filter('get_the_excerpt', 'new_excerpt_more');

  // Tags and Category for pages
  // add tag and category support to pages
function tags_categories_support_all() {
  register_taxonomy_for_object_type('post_tag', 'page');
  register_taxonomy_for_object_type('category', 'page');  
}

// ensure all tags and categories are included in queries
function tags_categories_support_query($wp_query) {
  if ($wp_query->get('tag')) $wp_query->set('post_type', 'any');
  if ($wp_query->get('category_name')) $wp_query->set('post_type', 'any');
}

// tag and category hooks
add_action('init', 'tags_categories_support_all');
add_action('pre_get_posts', 'tags_categories_support_query');


class Excerpt {

  // Default length (by WordPress)
  public static $length = 55;

  // So you can call: my_excerpt('short');
  public static $types = array(
      'short' => 25,
      'regular' => 55,
      'long' => 100
    );

  /**
   * Sets the length for the excerpt,
   * then it adds the WP filter
   * And automatically calls the_excerpt();
   *
   * @param string $new_length 
   * @return void
   * @author Baylor Rae'
   */
  public static function length($new_length = 55) {
    Excerpt::$length = $new_length;

    add_filter('excerpt_length', 'Excerpt::new_length');

    Excerpt::output();
  }

  // Tells WP the new length
  public static function new_length() {
    if( isset(Excerpt::$types[Excerpt::$length]) )
      return Excerpt::$types[Excerpt::$length];
    else
      return Excerpt::$length;
  }

  // Echoes out the excerpt
  public static function output() {
    the_excerpt();
  }

}

// An alias to the class
function my_excerpt($length = 55) {
  Excerpt::length($length);
}
  
?>