Enabled EC Parameters support

- Updated Api to enabled EC Parameters
- Updated Tests
- Updated Logging Manager
- Added a feature to do validation on accessors.

lib/PayPal/Validation/ArgumentValidator.php

@@ -0,0 +1,37 @@
+<?php
+
+namespace PayPal\Validation;
+
+/**
+ * Class ArgumentValidator
+ *
+ * @package PayPal\Validation
+ */
+class ArgumentValidator
+{
+
+    /**
+     * Helper method for validating an argument that will be used by this API in any requests.
+     *
+     * @param $argument     mixed The object to be validated
+     * @param $argumentName string|null The name of the argument.
+     *                      This will be placed in the exception message for easy reference
+     */
+    public static function validate($argument, $argumentName = null)
+    {
+        if (
+            $argument != null &&
+            (
+                (gettype($argument) == 'string' && $argument == '')
+                ||
+                is_array($argument) && empty($argument)
+            )
+        ) {
+            //Throw an Exception for string or array
+            throw new \InvalidArgumentException("$argumentName cannot be null or empty");
+        } elseif ($argument == null) {
+            //Generic Exception
+            throw new \InvalidArgumentException("$argumentName cannot be null");
+        }
+    }
+} 

lib/PayPal/Validation/ModelAccessorValidator.php

@@ -0,0 +1,44 @@
+<?php
+
+namespace PayPal\Validation;
+
+use PayPal\Common\PPModel;
+use PayPal\Core\PPConfigManager;
+use PayPal\Core\PPLoggingManager;
+
+/**
+ * Class ModelAccessorValidator
+ *
+ * @package PayPal\Validation
+ */
+class ModelAccessorValidator
+{
+    /**
+     * Helper method for validating if the class contains accessor methods (getter and setter) for a given attribute
+     *
+     * @param PPModel $class An object of PPModel
+     * @param string $attributeName Attribute name
+     * @return bool
+     */
+    public static function validate(PPModel $class, $attributeName)
+    {
+        $mode = PPConfigManager::getInstance()->get('validation.level');
+        if ($mode != 'disabled') {
+            //If the mode is disabled, bypass the validation
+            foreach (array('set' . $attributeName, 'get' . $attributeName) as $methodName) {
+                //Check if both getter and setter exists for given attribute
+                if (!method_exists($class, $methodName)) {
+                    //Delegate the error based on the choice
+                    $className = is_object($class) ? get_class($class) : (string)$class;
+                    $errorMessage = "Missing Accessor: $className:$methodName. Please let us know by creating an issue at https://github.com/paypal/rest-api-sdk-php/issues";
+                    PPLoggingManager::getInstance(__CLASS__)->warning($errorMessage);
+                    if ($mode == 'strict') {
+                        trigger_error($errorMessage, E_USER_NOTICE);
+                    }
+                    return false;
+                }
+            }
+        }
+        return true;
+    }
+}

lib/PayPal/Validation/UrlValidator.php

@@ -0,0 +1,26 @@
+<?php
+
+namespace PayPal\Validation;
+
+/**
+ * Class UrlValidator
+ *
+ * @package PayPal\Validation
+ */
+class UrlValidator
+{
+
+    /**
+     * Helper method for validating URLs that will be used by this API in any requests.
+     *
+     * @param      $url
+     * @param string|null $urlName
+     * @throws \InvalidArgumentException
+     */
+    public static function validate($url, $urlName = null)
+    {
+        if (filter_var($url, FILTER_VALIDATE_URL) === false) {
+            throw new \InvalidArgumentException("$urlName is not a fully qualified URL");
+        }
+    }
+}