Merge pull request #125 from pluginkollektiv/issue/112-refine-user-ag…

…ent-check

Ticket #112 - Enhanced bot detection.

inc/class-statify-frontend.php

@@ -165,7 +165,7 @@ private static function _skip_tracking() {
 		);
 		if ( is_null( $user_agent )
 			|| false === $user_agent
-			|| ! preg_match( '/(?:Windows|Macintosh|Linux|iPhone|iPad)/', $user_agent ) ) {
+			|| self::is_bot( $user_agent ) ) {
 			return true;
 		}
 
@@ -188,6 +188,37 @@ private static function _skip_tracking() {
 		return self::_is_internal();
 	}
 
+	/**
+	 * Checks if user agent is a bot.
+	 *
+	 * @since 1.7.0
+	 *
+	 * @param  string $user_agent Server user agent string.
+	 *
+	 * @return boolean $is_bot     TRUE if user agent is a bot, FALSE if not.
+	 */
+	private static function is_bot( $user_agent ) {
+		$user_agent = strtolower( $user_agent );
+
+		$identifiers = array(
+			'bot',
+			'slurp',
+			'crawler',
+			'spider',
+			'curl',
+			'facebook',
+			'fetch',
+		);
+
+		foreach ( $identifiers as $identifier ) {
+			if ( strpos( $user_agent, $identifier ) !== true ) {
+				return true;
+			}
+		}
+
+		return false;
+	}
+
 	/**
 	 * Rules to detect internal calls to skip tracking and not print code snippet.
 	 *