Add wrappers for sanitizing URLs and mail addresses

MD_STD_IN.php

@@ -136,4 +136,44 @@ final public static function get_http_post_text(string $var_name, string $defaul
 
     }
 
+    /**
+     * Sanitizes and validates a URL. An empty string passes.
+     *
+     * @param mixed $input Input string.
+     *
+     * @return string
+     */
+    final public static function sanitize_url($input):string {
+
+        if ($input === "") return $input;
+
+        $output = \filter_var($input, FILTER_SANITIZE_URL);
+        if (\filter_var($input, FILTER_VALIDATE_URL) === false) {
+            throw new MDInvalidUrl("Invalid input URL");
+        }
+
+        return $output;
+
+    }
+
+    /**
+     * Sanitizes and validates an e-mail address. An empty string passes.
+     *
+     * @param mixed $input Input string.
+     *
+     * @return string
+     */
+    final public static function sanitize_email($input):string {
+
+        if ($input === "") return $input;
+
+        $output = \filter_var($input, FILTER_SANITIZE_EMAIL);
+        if (\filter_var($input, FILTER_VALIDATE_EMAIL) === false) {
+            throw new MDInvalidEmail("Invalid input email address");
+        }
+
+        return $output;
+
+    }
+
 }