wp_head() Clean & Optimize & Secure WordPress

//code from wp.org/plugins/enable-classic-editor/ and another

if( !function_exists('classic_widgets')){

	function classic_widgets(){

		remove_theme_support( 'widgets-block-editor' );	

	}

	add_action( 'after_setup_theme', 'classic_widgets' );

}

add_filter('use_block_editor_for_post','__return_false');

add_filter( 'gutenberg_use_widgets_block_editor', '__return_false' );

add_filter( 'use_widgets_block_editor', '__return_false' );

// disable post revisions

define('WP_POST_REVISIONS', 0);



add_action( 'admin_enqueue_scripts', 'txz_admin_enqueue_scripts' );

function wps_cpt_admin_enqueue_scripts() {

    if ( 'post' == get_post_type() )

        wp_dequeue_script( 'autosave' );

    if ( 'txz' == get_post_type() )

        wp_dequeue_script( 'autosave' );

}



// removes the link to the Really Simple Discovery service endpoint, EditURI link

remove_action( 'wp_head', 'rsd_link' );



// removes the link to the Windows Live Writer manifest file.

remove_action( 'wp_head', 'wlwmanifest_link' );



// remove WP version on the XHTML generator that is generated on the wp_head hook

remove_action( 'wp_head', 'wp_generator' ); //only web

add_filter( 'the_generator', '__return_false' ); //all switch($type){ (wp-includes/general-template.php)



//Remove All Meta Generators https://stackoverflow.com/questions/16335347/wordpress-how-do-i-remove-meta-generator-tags

ini_set('output_buffering', 'on'); // turns on output_buffering

function remove_meta_generators($html) {

    $pattern = '/<meta name(.*)=(.*)"generator"(.*)>/i';

    $html = preg_replace($pattern, '', $html);

    return $html;

}

function clean_meta_generators($html) {

    ob_start('remove_meta_generators');

}

add_action('get_header', 'clean_meta_generators', 100);

add_action('wp_footer', function(){ ob_end_flush(); }, 100);



// remove admin bar

add_filter( 'show_admin_bar', '__return_false' );



// removes all extra rss comment feed links(%postname%/comment/feed/)

add_filter( 'feed_links_show_comments_feed', '__return_false' );



// removes the links to the general feeds: Post and Comment Feed

remove_action( 'wp_head', 'feed_links', 2 );



// removes all extra rss feed links(%postname%/feed/)

remove_action( 'wp_head', 'feed_links_extra', 3 );



// remove emoji js & css

remove_action( 'wp_head', 'print_emoji_detection_script', 7 );

remove_action( 'wp_print_styles', 'print_emoji_styles' );



// remove link 

remove_action( 'wp_head', 'wp_shortlink_wp_head' ); //short link (domain.ltd/?p=$post-id)

remove_action( 'wp_head', 'index_rel_link' ); // index link

remove_action( 'wp_head', 'parent_post_rel_link', 10, 0 ); // prev link

remove_action( 'wp_head', 'start_post_rel_link', 10, 0 ); // start link

remove_action( 'wp_head', 'adjacent_posts_rel_link' ); // Display relational links for the posts adjacent to the current post.



/*remove_action('wp_head','feed_links_extra', 3);

remove_action('wp_head','rsd_link');

remove_action('wp_head','feed_links', 2);

remove_action('wp_head','wlwmanifest_link');

remove_action('wp_head','index_rel_link');

remove_action('wp_head','parent_post_rel_link', 10, 0);

remove_action('wp_head','start_post_rel_link', 10, 0);

remove_action('wp_head','adjacent_posts_rel_link', 10, 0);

remove_action('wp_head','noindex');

remove_action('wp_head','wp_generator');

remove_action('wp_head','rel_canonical');

remove_action('wp_head', 'wp_shortlink_wp_head');*/



// Remove WP Version From Styles

add_filter( 'style_loader_src', 'sdt_remove_ver_css_js', 9999 );

// Remove WP Version From Scripts

add_filter( 'script_loader_src', 'sdt_remove_ver_css_js', 9999 );

// Function to remove version numbers

function sdt_remove_ver_css_js( $src ) {

//	if ( strpos( $src, 'ver='. get_bloginfo( 'version' ) ) ) // Remove only the "ver" parameter which have WordPress version

	if ( strpos( $src, 'ver=' ) ) // Remove the "ver" parameter from all enqueued CSS and JS files

		$src = remove_query_arg( 'ver', $src );

	return $src;

}



// move script form wp_head() to wp_footer()

remove_action('wp_head', 'wp_enqueue_scripts', 1);  // remove all .css & .js from wp_head()

add_action('wp_footer', 'wp_enqueue_scripts', 5);  // add all .css & .js to wp_footer()



// Disable REST API link tag

remove_action('wp_head', 'rest_output_link_wp_head', 10);



// Disable oEmbed Discovery Links

remove_action('wp_head', 'wp_oembed_add_discovery_links', 10);



// Disable REST API link in HTTP headers

remove_action('template_redirect', 'rest_output_link_header', 11, 0);

define('WP_POST_REVISIONS', 0);

remove_action('wp_head', 'wp_enqueue_scripts', 1);

add_action('wp_footer', 'wp_enqueue_scripts', 5);

remove_action('wp_head', 'rest_output_link_wp_head', 10);

remove_action('wp_head', 'wp_oembed_add_discovery_links', 10);

remove_action('template_redirect', 'rest_output_link_header', 11, 0);

remove_action('wp_head', 'rsd_link');

remove_action('wp_head', 'wlwmanifest_link');

remove_action('wp_head', 'wp_generator');

add_filter('the_generator', '__return_false');

add_filter('show_admin_bar', '__return_false');

add_filter('feed_links_show_comments_feed', '__return_false');

remove_action('wp_head', 'feed_links_extra', 3);

remove_action('wp_head', 'print_emoji_detection_script', 7);

remove_action('wp_print_styles', 'print_emoji_styles');

add_filter('style_loader_src', 'sdt_remove_ver_css_js', 9999);

add_filter('script_loader_src', 'sdt_remove_ver_css_js', 9999);

function sdt_remove_ver_css_js( $src ) {

	if (strpos($src, 'ver=')) // Remove the "ver" parameter from all enqueued CSS and JS files

		$src = remove_query_arg('ver', $src);

	return $src;

}

//https://developer.yoast.com/features/schema/api/#to-add-or-remove-graph-pieces

add_filter( 'wpseo_schema_graph_pieces', 'remove_breadcrumbs_from_schema', 11, 2 );

add_filter( 'wpseo_schema_webpage', 'remove_breadcrumbs_property_from_webpage', 11, 1 );

function remove_breadcrumbs_from_schema( $pieces, $context ) {

    return \array_filter( $pieces, function( $piece ) {

        return ! $piece instanceof \Yoast\WP\SEO\Generators\Schema\Breadcrumb;

    } );

}

function remove_breadcrumbs_property_from_webpage( $data ) {

    if (array_key_exists('breadcrumb', $data)) {

        unset($data['breadcrumb']);

    }

    return $data;

}

//remove inputbox url

add_filter('comment_form_default_fields', 'unset_url_field');

function unset_url_field($fields){

    if(isset($fields['url']))

       unset($fields['url']);

       return $fields;

}



/* https://www.wpbeginner.com/beginners-guide/vital-tips-and-tools-to-combat-comment-spam-in-wordpress/ */

function wpb_comment_post( $incoming_comment ) {

    $incoming_comment['comment_content'] = htmlspecialchars($incoming_comment['comment_content']);

    //$incoming_comment['comment_content'] = str_replace( "'", ''', $incoming_comment['comment_content']);

    return( $incoming_comment );

    }

    function wpb_comment_display( $comment_to_display ) {

     //$comment_to_display = str_replace( ''', "'", $comment_to_display );

     return $comment_to_display;

}

add_filter( 'preprocess_comment', 'wpb_comment_post', '', 1);

add_filter( 'comment_text', 'wpb_comment_display', '', 1);

add_filter( 'comment_text_rss', 'wpb_comment_display', '', 1);

add_filter( 'comment_excerpt', 'wpb_comment_display', '', 1);

remove_filter( 'comment_text', 'make_clickable', 9 );

/* https://wordpress.stackexchange.com/questions/52840/filter-all-html-output */

add_action('wp_loaded', 'buffer_start');    function buffer_start() { ob_start("myy_callback"); }

add_action('shutdown', 'buffer_end');       function buffer_end()   { ob_end_flush(); }

function myy_callback($buffer) {

  // modify buffer here, and then return the updated code

  $buffer = str_replace('findword','replaceword',$buffer);

  return $buffer;

}



/*only header https://wordpress.stackexchange.com/questions/226696/is-there-a-way-to-read-or-list-wp-head-contents */

function start_wp_head_buffer() {

    ob_start();

}

add_action('wp_head','start_wp_head_buffer',0);



function end_wp_head_buffer() {

    $in = ob_get_clean();



    // here do whatever you want with the header code

    echo $in; // output the result unless you want to remove it

}

add_action('wp_head','end_wp_head_buffer', PHP_INT_MAX); //PHP_INT_MAX will ensure this action is called after all other actions that can modify head



//https://stackoverflow.com/questions/30512084/wordpress-replace-meta-description

function remove_meta_descriptions($html) {

    $pattern = '//i';

    $html = preg_replace($pattern, '', $html);

    return $html;

}

function clean_meta_descriptions($html) {

    ob_start('remove_meta_descriptions');

}

add_action('get_header', 'clean_meta_descriptions', 100);

add_action('wp_footer', function(){ ob_end_flush(); }, 100);