Update functions.php

functions.php

@@ -77,6 +77,90 @@ function barebones_enqueue_scripts() {
 add_action( 'wp_enqueue_scripts', 'barebones_enqueue_scripts' );
 
 
+/**
+ * Add async and defer attributes to enqueued scripts
+ *
+ * @param string $tag
+ * @param string $handle
+ * @param string $src
+ * @return void
+ */
+
+function defer_scripts( $tag, $handle, $src ) {
+
+	// The handles of the enqueued scripts we want to defer
+	$defer_scripts = [
+        'SCRIPT_ID'
+    ];
+
+    // Find scripts in array and defer
+    if ( in_array( $handle, $defer_scripts ) ) {
+        return '<script type="text/javascript" src="' . $src . '" defer="defer"></script>' . "\n";
+    }
+    
+    return $tag;
+} 
+
+add_filter( 'script_loader_tag', 'defer_scripts', 10, 3 );
+
+
+/**
+ * Add custom scripts to head
+ *
+ * @return string
+ */
+
+function add_gtag_to_head() {
+
+    // Check is staging environment
+    if ( strpos( get_bloginfo( 'url' ), '.test' ) !== false ) return
+
+    // Google Analytics
+    $tracking_code = 'UA-*********-1';
+    
+    ?>
+        <!-- Global site tag (gtag.js) - Google Analytics -->
+        <script async src="https://www.googletagmanager.com/gtag/js?id=<?php echo $tracking_code; ?>"></script>
+        <script>
+            window.dataLayer = window.dataLayer || [];
+            function gtag(){dataLayer.push(arguments);}
+            gtag('js', new Date());
+
+            gtag('config', '<?php echo $tracking_code; ?>');
+        </script>
+    <?php
+}
+
+add_action( 'wp_head', 'add_gtag_to_head' );
+
+
+
+/**
+ * Remove unnecessary scripts
+ *
+ * @return void
+ */
+
+function deregister_scripts() {
+    wp_deregister_script( 'wp-embed' );
+}
+
+add_action( 'wp_footer', 'deregister_scripts' );
+
+
+/**
+ * Remove unnecessary styles
+ *
+ * @return void
+ */
+
+function deregister_styles() {
+    wp_dequeue_style( 'wp-block-library' );
+}
+
+add_action( 'wp_print_styles', 'deregister_styles', 100 );
+
+
 /**
  * Register nav menus
  *