Add CSRF token and store/return it in token() method

Wikimate.php

@@ -121,6 +121,15 @@ class Wikimate
 	 */
 	protected $maxretries = -1;
 
+	/**
+	 * Stored CSRF token for API requests
+	 *
+	 * @var string|null
+	 * @link https://www.mediawiki.org/wiki/Special:MyLanguage/API:Tokens
+	 * @link https://www.mediawiki.org/wiki/Special:MyLanguage/API:Edit#Additional_notes
+	 */
+	private $csrf_token = null;
+
 	/**
 	 * Creates a new Wikimate object.
 	 *
@@ -229,6 +238,9 @@ private function request($data, $headers = array(), $post = false)
 
 	/**
 	 * Obtains a wiki token for logging in or data-modifying actions.
+	 *
+	 * If a CSRF (default) token is requested, it is stored and returned
+	 * upon further such requests, instead of making another API call.
 	 * For now this method, in Wikimate tradition, is kept simple and supports
 	 * only the two token types needed elsewhere in the library.  It also
 	 * doesn't support the option to request multiple tokens at once.
@@ -247,6 +259,11 @@ protected function token($type = self::TOKEN_DEFAULT)
 			return false;
 		}
 
+		// Check for existing CSRF token for this login session
+		if ($type == self::TOKEN_DEFAULT && $this->csrf_token !== null) {
+			return $this->csrf_token;
+		}
+
 		$details = array(
 			'action' => 'query',
 			'meta' => 'tokens',
@@ -281,7 +298,9 @@ protected function token($type = self::TOKEN_DEFAULT)
 		if ($type == self::TOKEN_LOGIN) {
 			return $tokenResult['query']['tokens']['logintoken'];
 		} else {
-			return $tokenResult['query']['tokens']['csrftoken'];
+			// Store CSRF token for this login session
+			$this->csrf_token = $tokenResult['query']['tokens']['csrftoken'];
+			return $this->csrf_token;
 		}
 	}