Add function to get configured currency for contributionpage/event registration page

CRM/Core/Payment/MJWTrait.php

@@ -9,7 +9,7 @@
 
 trait CRM_Core_Payment_MJWTrait {
   /**********************
-   * MJW_Core_Payment_MJWTrait: 20190901
+   * MJW_Core_Payment_MJWTrait: 20190905
    *********************/
 
   /**
@@ -166,6 +166,29 @@ trait CRM_Core_Payment_MJWTrait {
     }
   }
 
+  /**
+   * Get the currency configured for the form when it is loaded
+   *
+   * @param \CRM_Core_Form $form
+   *
+   * @return string
+   */
+  public function getDefaultCurrencyForForm($form) {
+    // For contribution pages it is in $form->_values
+    $currency = CRM_Utils_Array::value('currency', $form->_values);
+    if (!$currency) {
+      // For event pages it is in $form->_values['event']
+      if (isset($form->_values['event'])) {
+        $currency = CRM_Utils_Array::value('currency', $form->_values['event']);
+      }
+    }
+    if (!$currency) {
+      // If we can't find it we'll use the default from the configuration
+      $currency = CRM_Core_Config::singleton()->defaultCurrency;
+    }
+    return $currency;
+  }
+
   /**
    *
    * @param array $params ['name' => payment instrument name]