functions.php

<?php
/*------------------------------------
 * Theme: Template by studio.bio 
 * File: Main functions file
 * Author: Joshua Michaels
 * URI: https://studio.bio/template
 *------------------------------------
 *
 * We've moved all of the theme functions to this single
 * file to keep things tidy. 
 *
 * Extra development and debugging functions can be found
 * in template.php. Uncomment the below require_once below.
 *
 */


// LOAD TEMPLATE DEVELOPMENT FUNCTIONS (not required but helper stuff for debugging and development)
// require_once( 'library/template.php' );

// CUSTOMIZE THE WORDPRESS ADMIN 
require_once( 'library/admin.php' );

/*********************
LAUNCH TEMPLATE
Let's get everything up and running.
*********************/

function template_launch() {

  //Allow editor style.
  add_editor_style( get_stylesheet_directory_uri() . '/library/css/editor-style.css' );

  // let's get language support going, if you need it
  //load_theme_textdomain( 'templatetheme', get_template_directory() . '/library/translation' );

  // launching operation cleanup
  add_action( 'init', 'template_head_cleanup' );
  // A better title
  add_filter( 'wp_title', 'rw_title', 10, 3 );
  // remove WP version from RSS
  add_filter( 'the_generator', 'template_rss_version' );
  // remove pesky injected css for recent comments widget
  add_filter( 'wp_head', 'template_remove_wp_widget_recent_comments_style', 1 );
  // clean up comment styles in the head
  add_action( 'wp_head', 'template_remove_recent_comments_style', 1 );
  // clean up gallery output in wp
  add_filter( 'gallery_style', 'template_gallery_style' );

  // enqueue base scripts and styles
  add_action( 'wp_enqueue_scripts', 'template_scripts_and_styles', 999 );
  // ie conditional wrapper

  // launching this stuff after theme setup
  template_theme_support();

  // adding sidebars to Wordpress (these are created in functions.php)
  add_action( 'widgets_init', 'template_register_sidebars' );

  // cleaning up random code around images
  add_filter( 'the_content', 'template_filter_ptags_on_images' );
  // cleaning up excerpt
  add_filter( 'excerpt_more', 'template_excerpt_more' );

} /* end template ahoy */

// let's get this party started
add_action( 'after_setup_theme', 'template_launch' );



/************* THUMBNAIL SIZE OPTIONS *************/

// Thumbnail sizes
add_image_size( 'template-image-600', 600, 600, true );
add_image_size( 'template-image-300', 300, 300, true );
add_image_size( 'template-image-300', 150, 150, true );

/*
to add more sizes, simply copy a line from above
and change the dimensions & name. As long as you
upload a "featured image" as large as the biggest
set width or height, all the other sizes will be
auto-cropped.

To call a different size, simply change the text
inside the thumbnail function.

For example, to call the 300 x 100 sized image,
we would use the function:
<?php the_post_thumbnail( 'template-image-300' ); ?>
for the 600 x 150 image:
<?php the_post_thumbnail( 'template-image-600' ); ?>

You can change the names and dimensions to whatever
you like. Enjoy!
*/

add_filter( 'image_size_names_choose', 'template_custom_image_sizes' );

function template_custom_image_sizes( $sizes ) {
    return array_merge( $sizes, array(
        'template-image-600' => __('600px by 600px', 'templatetheme'),
        'template-image-300' => __('300px by 300px', 'templatetheme'),
        'template-image-150' => __('150px by 150px', 'templatetheme'),
    ) );
}

/*
The function above adds the ability to use the dropdown menu to select
the new images sizes you have just created from within the media manager
when you add media to your content blocks. If you add more image sizes,
duplicate one of the lines in the array and name it according to your
new image size.
*/


/************* ACTIVE SIDEBARS ********************/

// Sidebars & Widgetizes Areas
function template_register_sidebars() {
	register_sidebar(array(
		'id' => 'sidebar1',
		'name' => __( 'Sidebar 1', 'templatetheme' ),
		'description' => __( 'The first (primary) sidebar.', 'templatetheme' ),
		'before_widget' => '<div id="%1$s" class="widget %2$s">',
		'after_widget' => '</div>',
		'before_title' => '<h4 class="widgettitle">',
		'after_title' => '</h4>',
	));

	/*
	to add more sidebars or widgetized areas, just copy
	and edit the above sidebar code. In order to call
	your new sidebar just use the following code:

	Just change the name to whatever your new
	sidebar's id is, for example:

	register_sidebar(array(
		'id' => 'sidebar2',
		'name' => __( 'Sidebar 2', 'templatetheme' ),
		'description' => __( 'The second (secondary) sidebar.', 'templatetheme' ),
		'before_widget' => '<div id="%1$s" class="widget %2$s">',
		'after_widget' => '</div>',
		'before_title' => '<h4 class="widgettitle">',
		'after_title' => '</h4>',
	));

	To call the sidebar in your template, you can just copy
	the sidebar.php file and rename it to your sidebar's name.
	So using the above example, it would be:
	sidebar-sidebar2.php

	*/
} // don't remove this bracket!


/*********************
COMMENTS
Blah blah blah.
*********************/

// Adding a custom gravatar. Customize this to add your own. Or delete it. It's totally up to you.
add_filter( 'avatar_defaults', 'new_default_avatar' );

function new_default_avatar ( $avatar_defaults ) {
    //Set the URL where the image file for your avatar is located
    $new_avatar_url = get_stylesheet_directory_uri() . '/library/images/custom-gravatar.jpg';
    // var_dump($new_avatar_url);
    //Set the text that will appear to the right of your avatar in Settings>>Discussion
    $avatar_defaults[$new_avatar_url] = 'Custom Avatar';
    return $avatar_defaults;
}


// Comment Layout
function template_comments( $comment, $args, $depth ) {
   $GLOBALS['comment'] = $comment; ?>
  <div id="comment-<?php comment_ID(); ?>" <?php comment_class('cf'); ?>>
    <article  class="cf">
      <header class="comment-author vcard">
        <?php
        /*
          this is the new responsive optimized comment image. It used the new HTML5 data-attribute to display comment gravatars on larger screens only. What this means is that on larger posts, mobile sites don't have a ton of requests for comment images. This makes load time incredibly fast! If you'd like to change it back, just replace it with the regular wordpress gravatar call:
          echo get_avatar($comment,$size='32',$default='<path_to_url>' );
        */
        ?>
        <?php // custom gravatar call ?>
        <?php
          // create variable
          $bgauthemail = get_comment_author_email();
        ?>
        <img data-gravatar="//www.gravatar.com/avatar/<?php echo md5( $bgauthemail ); ?>?s=40" class="load-gravatar avatar avatar-48 photo" height="40" width="40" src="<?php echo get_template_directory_uri(); ?>/library/images/nothing.gif" />
        <?php // end custom gravatar call ?>
        <?php printf(__( '<cite class="fn">%1$s</cite> %2$s', 'templatetheme' ), get_comment_author_link(), edit_comment_link(__( '(Edit)', 'templatetheme' ),'  ','') ) ?>
        <time datetime="<?php echo comment_time('Y-m-j'); ?>"><a href="<?php echo htmlspecialchars( get_comment_link( $comment->comment_ID ) ) ?>"><?php comment_time(__( 'F jS, Y', 'templatetheme' )); ?> </a></time>

      </header>
      <?php if ($comment->comment_approved == '0') : ?>
        <div class="alert alert-info">
          <p><?php _e( 'Your comment is awaiting moderation.', 'templatetheme' ) ?></p>
        </div>
      <?php endif; ?>
      <section class="comment_content cf">
        <?php comment_text() ?>
      </section>
      <?php comment_reply_link(array_merge( $args, array('depth' => $depth, 'max_depth' => $args['max_depth']))) ?>
    </article>
  <?php // </li> is added by WordPress automatically ?>
<?php
} // don't remove this bracket!


/*
Use this to add Google or other web fonts.
*/
// function template_fonts() {
//   wp_enqueue_style('templateFonts', 'http://fonts.googleapis.com/css?family=Open+Sans:400,600,400italic,');
// }

// add_action('wp_enqueue_scripts', 'template_fonts');


/****************************************
* SCHEMA *
http://www.longren.io/add-schema-org-markup-to-any-wordpress-theme/
****************************************/

function html_schema() {

    $schema = 'http://schema.org/';
 
    // Is single post
    if( is_single()) {
        $type = "Article";
    }
    // Is blog home, archive or category
    else if( is_home() || is_archive() || is_category() ) {
        $type = "Blog";
    }
    // Is static front page
    else if( is_front_page()) {
        $type = "Website";
    }
    // Is a general page
     else {
        $type = 'WebPage';
    }
 
    echo 'itemscope="itemscope" itemtype="' . $schema . $type . '"';
}



/*********************
WP_HEAD GOODNESS
The default wordpress head is
a mess. Let's clean it up by
removing all the junk we don't
need.
*********************/

function template_head_cleanup() {
  // category feeds
  remove_action( 'wp_head', 'feed_links_extra', 3 );
  // post and comment feeds
  remove_action( 'wp_head', 'feed_links', 2 );
  // EditURI link
  remove_action( 'wp_head', 'rsd_link' );
  // windows live writer
  remove_action( 'wp_head', 'wlwmanifest_link' );
  // previous link
  remove_action( 'wp_head', 'parent_post_rel_link', 10, 0 );
  // start link
  remove_action( 'wp_head', 'start_post_rel_link', 10, 0 );
  // links for adjacent posts
  remove_action( 'wp_head', 'adjacent_posts_rel_link_wp_head', 10, 0 );
  // WP version
  remove_action( 'wp_head', 'wp_generator' );
  // remove WP version from css
  add_filter( 'style_loader_src', 'template_remove_wp_ver_css_js', 9999 );
  // remove WP version from scripts
  add_filter( 'script_loader_src', 'template_remove_wp_ver_css_js', 9999 );

} /* end template head cleanup */


// remove WP version from RSS
function template_rss_version() { return ''; }

// remove WP version from scripts
function template_remove_wp_ver_css_js( $src ) {
  if ( strpos( $src, 'ver=' ) )
    $src = remove_query_arg( 'ver', $src );
  return $src;
}

// remove injected CSS for recent comments widget
function template_remove_wp_widget_recent_comments_style() {
  if ( has_filter( 'wp_head', 'wp_widget_recent_comments_style' ) ) {
    remove_filter( 'wp_head', 'wp_widget_recent_comments_style' );
  }
}

// remove injected CSS from recent comments widget
function template_remove_recent_comments_style() {
  global $wp_widget_factory;
  if (isset($wp_widget_factory->widgets['WP_Widget_Recent_Comments'])) {
    remove_action( 'wp_head', array($wp_widget_factory->widgets['WP_Widget_Recent_Comments'], 'recent_comments_style') );
  }
}

// remove injected CSS from gallery
function template_gallery_style($css) {
  return preg_replace( "!<style type='text/css'>(.*?)</style>!s", '', $css );
}


/*********************
SCRIPTS & ENQUEUEING
*********************/

// loading modernizr and jquery, and reply script
function template_scripts_and_styles() {

  global $wp_styles; // call global $wp_styles variable to add conditional wrapper around ie stylesheet the WordPress way

  if (!is_admin()) {

    // modernizr (without media query polyfill)
    wp_register_script( 'template-modernizr', get_stylesheet_directory_uri() . '/library/js/libs/modernizr-custom.js', array(), '3.5.0', false );

    // register main stylesheet
    wp_register_style( 'template-stylesheet', get_stylesheet_directory_uri() . '/library/css/style.css', array(), '', 'all' );

    // ie-only style sheet
    wp_register_style( 'template-ie-only', get_stylesheet_directory_uri() . '/library/css/ie.css', array(), '' );

    // comment reply script for threaded comments
    if ( is_singular() AND comments_open() AND (get_option('thread_comments') == 1)) {
      wp_enqueue_script( 'comment-reply' );
    }

    //adding scripts file in the footer
    wp_register_script( 'template-js', get_stylesheet_directory_uri() . '/library/js/scripts.js', array( 'jquery' ), '', true );

    // Template extra scripts. Uncomment to use. Or better yet, copy what you need to the main scripts folder or on the page(s) you need it
    // wp_register_script( 'template-extra-js', get_stylesheet_directory_uri() . '/library/js/extras/extra-scripts.js', array( 'jquery' ), '', true );

    // enqueue styles and scripts
    wp_enqueue_script( 'template-modernizr' );
    wp_enqueue_style( 'template-stylesheet' );
    wp_enqueue_style( 'template-ie-only' );

    $wp_styles->add_data( 'template-ie-only', 'conditional', 'lt IE 9' ); // add conditional wrapper around ie stylesheet

    wp_enqueue_script( 'jquery' );
    wp_enqueue_script( 'template-js' );
    // wp_enqueue_script( 'template-extra-js' );

  }
}

/****************************************
* REMOVE WP EXTRAS *
****************************************/

// Remove emojis: because WordPress is serious business.
// But, if you want emojis, don't let me stop you from having a good time. 
// To enable emojis, comment these functions out or just delete them.

add_action( 'init', 'disable_wp_emojicons' );

function disable_wp_emojicons() {

  // all actions related to emojis
  remove_action( 'admin_print_styles', 'print_emoji_styles' );
  remove_action( 'wp_head', 'print_emoji_detection_script', 7 );
  remove_action( 'admin_print_scripts', 'print_emoji_detection_script' );
  remove_action( 'wp_print_styles', 'print_emoji_styles' );
  remove_filter( 'wp_mail', 'wp_staticize_emoji_for_email' );
  remove_filter( 'the_content_feed', 'wp_staticize_emoji' );
  remove_filter( 'comment_text_rss', 'wp_staticize_emoji' );

  // filter to remove TinyMCE emojis
  add_filter( 'tiny_mce_plugins', 'disable_emojicons_tinymce' );
}

function disable_emojicons_tinymce( $plugins ) {
  if ( is_array( $plugins ) ) {
    return array_diff( $plugins, array( 'wpemoji' ) );
  } else {
    return array();
  }
}


// Dequeue jQuery Migrate
add_action( 'wp_default_scripts', 'template_dequeue_jquery_migrate' );
function template_dequeue_jquery_migrate( $scripts ) {
  if (! empty( $scripts->registered['jquery'] ) ) {
    $jquery_dependencies = $scripts->registered['jquery']->deps;
    $scripts->registered['jquery']->deps = array_diff( $jquery_dependencies, array( 'jquery-migrate' ) );
  }
}


/*********************
THEME SUPPORT
*********************/

// Adding WP 3+ Functions & Theme Support
function template_theme_support() {

  // wp thumbnails (sizes handled in functions.php)
  add_theme_support( 'post-thumbnails' );

  // default thumb size
  set_post_thumbnail_size(125, 125, true);

  // wp custom background (thx to @bransonwerner for update)
  add_theme_support( 'custom-background',
      array(
      'default-image' => '',    // background image default
      'default-color' => '',    // background color default (dont add the #)
      'wp-head-callback' => '_custom_background_cb',
      'admin-head-callback' => '',
      'admin-preview-callback' => ''
      )
  );

  // Custom Header Image
  add_theme_support( 'custom-header', array( 
    'default-image'          => get_template_directory_uri() . '/library/images/header-image.png',
      'default-text-color'     => 'ffffff',
      'header-text'            => true,
      'uploads'                => true,
      'wp-head-callback'       => 'template_style_header'
  ) );

  // Custom Logo
  add_theme_support( 'custom-logo', array(
    'height'      => 100,
    'width'       => 400,
    'flex-height' => true,
    'flex-width'  => true,
    'header-text' => array( 'site-title', 'site-description' ),
  ) );

  // rss thingy
  add_theme_support('automatic-feed-links');

  // wp menus
  add_theme_support( 'menus' );

  // registering wp3+ menus
  // To add another menu, uncomment the second line and change it to whatever you want. You can have even more menus.
  register_nav_menus(
    array(
      'main-nav' => __( 'The Main Menu', 'templatetheme' ),   // main nav in header
      // 'footer-links' => __( 'Footer Links', 'templatetheme' ) // secondary nav in footer. Uncomment to use
    )
  );

  // Title tag
  add_theme_support( 'title-tag' );

  // Enable support for HTML5 markup.
  add_theme_support( 'html5', array( 
    'comment-list', 
    'comment-form', 
    'search-form', 
    'gallery', 
    'caption' ) 
  );

  /* Post Formats
  Ahhhh yes, the wild and wonderful world of Post Formats. 
  I've never really gotten into them but I could see some
  situations where they would come in handy. Here's a few
  examples: https://www.competethemes.com/blog/wordpress-post-format-examples/

  This theme doesn't use post formats per se but we need this 
  to pass the theme check.

  We may add better support for post formats in the future.

  If you want to use them in your project, do so by all means. 
  We won't judge you.
  */

  add_theme_support( 'post-formats',
   array(
     'aside',             // title less blurb
     'gallery',           // gallery of images
     'link',              // quick link to other site
     'image',             // an image
     'quote',             // a quick quote
     'status',            // a Facebook like status update
     'video',             // video
     'audio',             // audio
     'chat'               // chat transcript
   )
  );

} /* end template theme support */


/* Add WooCommerce support. This function only removes the warning 
in the WP admin when WooCommerce is installed. To fully support
WooCommerce you will need to add some stuff to your product loops.
See here: https://docs.woocommerce.com/document/third-party-custom-theme-compatibility/
*/
add_action( 'after_setup_theme', 'woocommerce_support' );
function woocommerce_support() {
    add_theme_support( 'woocommerce' );
}


/****************************************
* CUSTOMIZER *
****************************************/

add_action( 'customize_register', 'template_register_theme_customizer' );

function template_register_theme_customizer( $wp_customize ) {

  // Uncomment this to see what's going on if you make a lot of changes
  // echo '<pre>';
  // var_dump( $wp_customize );  
  // echo '</pre>';

  // Customize title and tagline sections and labels
  $wp_customize->get_section('title_tagline')->title = __('Site Name and Description', 'templatetheme');  
  $wp_customize->get_control('blogname')->label = __('Site Name', 'templatetheme');  
  $wp_customize->get_control('blogdescription')->label = __('Site Description', 'templatetheme');  
  $wp_customize->get_setting( 'blogname' )->transport = 'postMessage';
  $wp_customize->get_setting( 'blogdescription' )->transport  = 'postMessage';

  // Customize the Front Page Settings
  $wp_customize->get_section('static_front_page')->title = __('Homepage Preferences', 'templatetheme');
  $wp_customize->get_section('static_front_page')->priority = 20;
  $wp_customize->get_control('show_on_front')->label = __('Choose Homepage Preference:', 'templatetheme');  
  $wp_customize->get_control('page_on_front')->label = __('Select Homepage:', 'templatetheme');  
  $wp_customize->get_control('page_for_posts')->label = __('Select Blog Homepage:', 'templatetheme');  

  // Customize Background Settings
  $wp_customize->get_section('background_image')->title = __('Background Styles', 'templatetheme');  
  $wp_customize->get_control('background_color')->section = 'background_image'; 

  // Customize Header Image Settings  
  $wp_customize->add_section( 'header_text_styles' , array(
    'title'      => __('Header Text Styles','templatetheme'), 
    'priority'   => 30    
  ) );
  $wp_customize->get_control('display_header_text')->section = 'header_text_styles';  
  $wp_customize->get_control('header_textcolor')->section = 'header_text_styles'; 
  $wp_customize->get_setting( 'header_textcolor' )->transport = 'postMessage'; 

}


// Custom scripts + styles for theme customizer
add_action( 'customize_preview_init', 'template_customizer_scripts' );

function template_customizer_scripts() {
  wp_enqueue_script(
    'template_theme_customizer',
    get_template_directory_uri() . '/library/js/theme-customizer.js',
    array( 'jquery', 'customize-preview' ),
    '',
    true
  );

  // register customizer stylesheet
  wp_register_style( 'template-customizer', get_stylesheet_directory_uri() . '/library/css/customizer.css', array(), '', 'all' );
  wp_enqueue_style( 'template-customizer' );

}


// Callback function for updating header styles
function template_style_header() {

  $text_color = get_header_textcolor();
  
  ?>
  
  <style type="text/css">

    header.header .site-title a {
      color: #<?php echo esc_attr( $text_color ); ?>;
    }
  
    <?php if(display_header_text() != true): ?>
    .site-title, .site-description {
      display: none;
    } 
    <?php endif; ?>

    #banner .header-image {
      max-width: 100%;
      height: auto;
    }

    .customize-control-description {
      font-style: normal;
    }

  </style>
  <?php 

}

/*********************
RELATED POSTS FUNCTION
*********************/

// Related Posts Function (call using template_related_posts(); )
function template_related_posts() {
  echo '<ul id="template-related-posts">';
  global $post;
  $tags = wp_get_post_tags( $post->ID );
  if($tags) {
    foreach( $tags as $tag ) {
      $tag_arr .= $tag->slug . ',';
    }
    $args = array(
      'tag' => $tag_arr,
      'numberposts' => 5, /* you can change this to show more */
      'post__not_in' => array($post->ID)
    );
    $related_posts = get_posts( $args );
    if($related_posts) {
      foreach ( $related_posts as $post ) : setup_postdata( $post ); ?>
        <li class="related_post"><a class="entry-unrelated" href="<?php the_permalink() ?>" title="<?php the_title_attribute(); ?>"><?php the_title(); ?></a></li>
      <?php endforeach; }
    else { ?>
      <?php echo '<li class="no_related_post">' . __( 'No Related Posts Yet!', 'templatetheme' ) . '</li>'; ?>
    <?php }
  }
  wp_reset_postdata();
  echo '</ul>';
} /* end template related posts function */

/*********************
PAGE NAVI
*********************/

// Numeric Page Navi (built into the theme by default)
function template_page_navi() {
  global $wp_query;
  $bignum = 999999999;
  if ( $wp_query->max_num_pages <= 1 )
    return;
  echo '<nav class="pagination">';
  echo paginate_links( array(
    'base'         => str_replace( $bignum, '%#%', esc_url( get_pagenum_link($bignum) ) ),
    'format'       => '',
    'current'      => max( 1, get_query_var('paged') ),
    'total'        => $wp_query->max_num_pages,
    'prev_text'    => '&larr;',
    'next_text'    => '&rarr;',
    'type'         => 'list',
    'end_size'     => 3,
    'mid_size'     => 3
  ) );
  echo '</nav>';
} /* end page navi */

/*********************
RANDOM CLEANUP ITEMS
*********************/

// remove the p from around imgs (http://css-tricks.com/snippets/wordpress/remove-paragraph-tags-from-around-images/)
function template_filter_ptags_on_images($content){
  return preg_replace('/<p>\s*(<a .*>)?\s*(<img .* \/>)\s*(<\/a>)?\s*<\/p>/iU', '\1\2\3', $content);
}

// This removes the annoying […] to a Read More link
function template_excerpt_more($more) {
  global $post;
  // edit here if you like
  return '...  <a class="excerpt-read-more" href="'. get_permalink( $post->ID ) . '" title="'. __( 'Read ', 'templatetheme' ) . esc_attr( get_the_title( $post->ID ) ).'">'. __( 'Read more &raquo;', 'templatetheme' ) .'</a>';
}


/*
****************************************
*      TEMPLATE SPECIAL FUNCTIONS      *
****************************************
*/

// Body Class functions
// Adds more slugs to body class so we can style individual pages + posts.
// Page Slug Body Class
add_filter( 'body_class', 'template_body_class' );

function template_body_class( $classes ) {
global $post;
  if ( isset( $post ) ) {
  /* $classes[] = $post->post_type . '-' . $post->post_name; *//*Un comment this if you want the post_type-post_name body class */
  $pagetemplate = get_post_meta( $post->ID, '_wp_page_template', true);
  $classes[] = sanitize_html_class( str_replace( '.', '-', $pagetemplate ), '' );
  $classes[] = $post->post_name;
  }

if (is_page()) {
        global $post;
        if ( $post->post_parent ) {
            # Parent post name/slug
            $parent = get_post( $post->post_parent );
            $classes[] = $parent->post_name;

            # Parent template name
            $parent_template = get_post_meta( $parent->ID, '_wp_page_template', true);
            
            if ( !empty($parent_template) )
                $classes[] = 'template-'.sanitize_html_class( str_replace( '.', '-', $parent_template ), '' );
        }
        
        // If we *do* have an ancestors list, process it
        // http://codex.wordpress.org/Function_Reference/get_post_ancestors
        if ($parents = get_post_ancestors($post->ID)) {
            foreach ((array)$parents as $parent) {
                // As the array contains IDs only, we need to get each page
                if ($page = get_page($parent)) {
                    // Add the current ancestor to the body class array
                    $classes[] = "{$page->post_type}-{$page->post_name}";
                }
            }
        }
 
        // Add the current page to our body class array
        $classes[] = "{$post->post_type}-{$post->post_name}";
    }

return $classes;

}


// Let's add some extra Quicktags
// These come in handy especially for clients who aren't HTML masters
// Hook into the 'admin_print_footer_scripts' action
add_action( 'admin_print_footer_scripts', 'template_custom_quicktags' );

function template_custom_quicktags() {

  if ( wp_script_is( 'quicktags' ) ) {
  ?>
  <script type="text/javascript">
  QTags.addButton( 'qt-p', 'p', '<p>', '</p>', '', '', 1 );
  QTags.addButton( 'qt-br', 'br', '<br>', '', '', '', 9 );
  QTags.addButton( 'qt-span', 'span', '<span>', '</span>', '', '', 11 );
  QTags.addButton( 'qt-h2', 'h2', '<h2>', '</h2>', '', '', 12 );
  QTags.addButton( 'qt-h3', 'h3', '<h3>', '</h3>', '', '', 13 );
  QTags.addButton( 'qt-h4', 'h4', '<h4>', '</h4>', '', '', 14 );
  QTags.addButton( 'qt-h5', 'h5', '<h5>', '</h5>', '', '', 15 );
  </script>
  <?php
  }

}

// Load dashicons on the front end
// To use, go here and copy the css/html for the dashicon you want: https://developer.wordpress.org/resource/dashicons/
// Example: <span class="dashicons dashicons-wordpress"></span>
add_action( 'wp_enqueue_scripts', 'template_load_dashicons' );
function template_load_dashicons() {
    wp_enqueue_style( 'dashicons' );
}


// Post Author function (from WP Twenty Seventeen theme)
// We use this in the byline template part but included here in case you want to use it elsewhere.
if ( ! function_exists( 'template_posted_on' ) ) :
/**
 * Prints HTML with meta information for the current post-date/time and author.
 */
function template_posted_on() {

  // Get the author name; wrap it in a link.
  $byline = sprintf(
    /* translators: %s: post author */
    __( 'by %s', 'templatetheme' ),
    '<span class="author vcard"><a class="url fn n" href="' . esc_url( get_author_posts_url( get_the_author_meta( 'ID' ) ) ) . '">' . get_the_author() . '</a></span>'
  );

  // Finally, let's write all of this to the page.
  echo '<span class="posted-on">' . template_time_link() . '</span><span class="byline"> ' . $byline . '</span>';
}
endif;

// Post Time function (from WP Twenty Seventeen theme)
if ( ! function_exists( 'template_time_link' ) ) :
/**
 * Gets a nicely formatted string for the published date.
 */
function template_time_link() {
  $time_string = '<time class="entry-date published updated" datetime="%1$s">%2$s</time>';
  // if ( get_the_time( 'U' ) !== get_the_modified_time( 'U' ) ) {
  //   $time_string = '<time class="entry-date published" datetime="%1$s">%2$s</time><time class="updated" datetime="%3$s">%4$s</time>';
  // }

  $time_string = sprintf( $time_string,
    get_the_date( DATE_W3C ),
    get_the_date(),
    get_the_modified_date( DATE_W3C ),
    get_the_modified_date()
  );

  // Wrap the time string in a link, and preface it with 'Posted on'.
  return sprintf(
    /* translators: %s: post date */
    __( '<span class="screen-reader-text">Posted on</span> %s', 'templatetheme' ),
    '<a href="' . esc_url( get_permalink() ) . '" rel="bookmark">' . $time_string . '</a>'
  );
}
endif;

?>