Improve performance by performing fewer API calls and storing issuers…

… and methods in transient cache

MPM/mpm_gateway.php

@@ -27,11 +27,24 @@
 
 class MPM_Gateway extends WC_Payment_Gateway
 {
+	/**
+	 * Does this payment method have any extra fields? Only iDEAL has extra fields.
+	 *
+	 * @var bool
+	 */
+	public $has_fields = FALSE;
+
 	protected $_data = null;
 
+	/**
+	 * @var Mollie_API_Object_Issuer[]
+	 */
+	protected $issuers = array();
+
 	public function __construct()
 	{
 		// Register this method with MPM_Settings
+		/** @var MPM_Settings $mpm */
 		global $mpm;
 		$methods = $mpm->get_methods();
 		if ($mpm->count >= count($methods))
@@ -48,15 +61,11 @@ public function __construct()
 		$this->title = __($this->_data->description, 'MPM'); // translate visual title
 
 		// Define issuers (if any)
-		$issuers = $mpm->get_api()->issuers->all();
-		$this->has_fields = FALSE;
-		$this->issuers = array();
-		foreach ($issuers as $issuer)
-		{
-			if ($issuer->method === $this->id) {
-				$this->has_fields = TRUE;
-				$this->issuers[] = $issuer;
-			}
+		$this->issuers = $mpm->get_issuers($this->id);
+
+		if (!empty($this->issuers))
+		{
+			$this->has_fields = TRUE;
 		}
 
 		// Assign image

MPM/mpm_settings.php

@@ -29,7 +29,6 @@ class MPM_Settings extends WC_Settings_API
 {
 	// Keep track of payment methods
 	public $count = 0;
-	protected $methods = array();
 
 	/** @var $api Mollie_API_Client|null */
 	protected $api = null;
@@ -410,27 +409,93 @@ public function get_api()
 	}
 
 	/**
-	 * Retrieve the Mollie methods
+	 * @var NULL|Mollie_API_Object_Method[]
+	 */
+	private static $_methods;
+
+	/**
+	 * Retrieve the enabled payment methods from the Mollie API. Caches these for about a minute.
+	 *
 	 * @return array|Mollie_API_Object_List|Mollie_API_Object_Method[]
 	 */
 	public function get_methods()
 	{
-		// If we have them, give them
-		if (!empty($this->methods))
+		// Retrieve the methods or fail with error
+		try
 		{
-			return $this->methods;
+			if (empty(self::$_methods))
+			{
+				$cached = @unserialize(get_transient('mpm_api_methods'));
+
+				if ($cached instanceof Mollie_API_Object_List)
+				{
+					self::$_methods = $cached;
+				}
+				else
+				{
+					self::$_methods = $this->get_api()->methods->all();
+					set_transient('mpm_api_methods', self::$_methods, MINUTE_IN_SECONDS);
+				}
+			}
+
+			return self::$_methods;
 		}
-		// If we don't even have the api yet, get it
-		if (is_null($this->api))
+		catch (Mollie_API_Exception $e)
 		{
-			$this->api = $this->get_api();
+			$this->errors[] = __('Payment error:', 'MPM') . $e->getMessage();
+			$this->display_errors();
+			return array();
 		}
+	}
 
-		// Retrieve the methods or fail with error
+	/**
+	 * @var NULL|Mollie_API_Object_Issuer[]
+	 */
+	private static $_issuers;
+
+	/**
+	 * Get the issuers from the Mollie API. Caches these in Wordpress cache for about a day.
+	 *
+	 * @param string|NULL $method Filter issuers by method
+	 * @return Mollie_API_Object_Issuer[]
+	 */
+	public function get_issuers ($method = NULL)
+	{
+		// Retrieve the issuers or fail with error
 		try
 		{
-			$this->methods = $this->api->methods->all();
-			return $this->methods;
+			if (empty(self::$_issuers))
+			{
+				$cached = @unserialize(get_transient('mpm_api_issuers'));
+
+				if ($cached instanceof Mollie_API_Object_List)
+				{
+					self::$_issuers = $cached;
+				}
+				else
+				{
+					self::$_issuers = $this->get_api()->issuers->all();
+					set_transient('mpm_api_issuers', self::$_issuers, DAY_IN_SECONDS);
+				}
+			}
+
+			// Filter issuers by method
+			if ($method !== NULL)
+			{
+				$issuers = array();
+
+				foreach(self::$_issuers AS $issuer)
+				{
+					if ($issuer->method === $method)
+					{
+						$issuers[] = $issuer;
+					}
+				}
+
+				return $issuers;
+			}
+
+			return self::$_issuers;
 		}
 		catch (Mollie_API_Exception $e)
 		{