Wordpress performance snippets for functions.php

functions-performance-php

################# performance snippets ###########################################

/**
 * decrease jpeg quality to 80
 */
add_filter( 'jpeg_quality', create_function( '', 'return 80;' ) );

/**
 * Disable the emoji's
 */
function disable_emojis() {
	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_action( 'admin_print_styles', 'print_emoji_styles' );	
	remove_filter( 'the_content_feed', 'wp_staticize_emoji' );
	remove_filter( 'comment_text_rss', 'wp_staticize_emoji' );	
	remove_filter( 'wp_mail', 'wp_staticize_emoji_for_email' );
	add_filter( 'tiny_mce_plugins', 'disable_emojis_tinymce' );
}
add_action( 'init', 'disable_emojis' );

/**
 * Filter function used to remove the tinymce emoji plugin.
 * 
 * @param    array  $plugins  
 * @return   array             Difference betwen the two arrays
 */
function disable_emojis_tinymce( $plugins ) {
	if ( is_array( $plugins ) ) {
		return array_diff( $plugins, array( 'wpemoji' ) );
	} else {
		return array();
	}
}

// Remove WP embed script
function speed_stop_loading_wp_embed() {
	if (!is_admin()) {
		wp_deregister_script('wp-embed');
	}
}
add_action('init', 'speed_stop_loading_wp_embed');

// Remove Query Strings
function _remove_script_version( $src ){
	$parts = explode( '?ver', $src );
	return $parts[0];
}
add_filter( 'script_loader_src', '_remove_script_version', 15, 1 );
add_filter( 'style_loader_src', '_remove_script_version', 15, 1 );

// defer parsing solution.
// add at the bottom of your child theme functions.php
add_filter('clean_url','async_js',11);
function async_js($url) {
      if ( false !== strpos( $url, 'jquery.js' ) || false === strpos( $url, '.js' )) {
          return $url;
      }
      return "$url' defer='defer";        
} 

clean_url filter geplaatst voor het defer parser solution die GT matrix geeft.