[com_fields] Add Joomla loading overlay when form submit is triggered…

… by category selector change (joomla#13320)

* Added overlay box and message box for submit and reload form after category change

* Removed commented testing code

* Added language strings

* CS fix, added missing spaces

* Used Joomla logo spinner instead of fixed message

* Reverted changes in admin lang file

* CS

* Revert frontend lang changes

* Added Joomla loading overlay to new field form when changing field type

* Added Joomla.loadingLayer show to typeHasChanged JS method too

administrator/components/com_fields/helpers/fields.php

@@ -320,15 +320,19 @@ public static function prepareForm($context, JForm $form, $data)
 			 * has changed
 			*/
 			$form->setFieldAttribute('catid', 'onchange', 'categoryHasChanged(this);');
-			JFactory::getDocument()->addScriptDeclaration(
-					"function categoryHasChanged(element){
+
+			// Preload spindle-wheel when we need to submit form due to category selector changed
+			JFactory::getDocument()->addScriptDeclaration("
+			function categoryHasChanged(element) {
+				Joomla.loadingLayer('show');
 				var cat = jQuery(element);
 				if (cat.val() == '" . $assignedCatids . "')return;
 				jQuery('input[name=task]').val('field.storeform');
 				element.form.action='" . $uri . "';
 				element.form.submit();
 			}
 			jQuery( document ).ready(function() {
+				Joomla.loadingLayer('load');
 				var formControl = '#" . $form->getFormControl() . "_catid';
 				if (!jQuery(formControl).val() != '" . $assignedCatids . "'){jQuery(formControl).val('" . $assignedCatids . "');}
 			});");

administrator/components/com_fields/models/fields/type.php

@@ -86,13 +86,19 @@ function ($a, $b)
 		$uri->setVar('view', null);
 		$uri->setVar('layout', null);
 
-		JFactory::getDocument()->addScriptDeclaration(
-				"function typeHasChanged(element){
+
+		JFactory::getDocument()->addScriptDeclaration("
+			jQuery( document ).ready(function() {
+				Joomla.loadingLayer('load');
+			});
+			function typeHasChanged(element){
+				Joomla.loadingLayer('show');
 				var cat = jQuery(element);
 				jQuery('input[name=task]').val('field.storeform');
 				element.form.action='" . $uri . "';
 				element.form.submit();
-			}");
+			}
+		");
 
 		return $options;
 	}