Make it works with Translatable module

code/ModelAdmin/SEOEditorAdmin.php

@@ -45,6 +45,8 @@ public function init()
         parent::init();
         Requirements::css('silverstripe-seo-editor/css/seo-editor.css');
         Requirements::javascript('silverstripe-seo-editor/javascript/seo-editor.js');
+
+        if(class_exists('Translatable')) Requirements::javascript('silverstripe-seo-editor/javascript/SEOEditor.Translatable.js');
     }
 
     /**
@@ -62,6 +64,25 @@ public function getSearchContext()
             CheckboxField::create('RemoveEmptyMetaTitles', 'Remove Empty MetaTitles'),
             CheckboxField::create('RemoveEmptyMetaDescriptions', 'Remove Empty MetaDescriptions')
         );
+
+        if(class_exists('Translatable')) {
+            $member = Member::currentUser(); //check to see if the current user can switch langs or not
+    		if(Permission::checkMember($member, 'VIEW_LANGS')) {
+                $field = new LanguageDropdownField(
+    				'locale',
+                    _t('CMSMain.LANGUAGEDROPDOWNLABEL', 'Language')
+    			);
+    			$field->setValue(Translatable::get_current_locale());
+            } else {
+    			// user doesn't have permission to switch langs
+    			// so just show a string displaying current language
+    			$field = new LiteralField(
+    				'locale',
+    				i18n::get_locale_name( Translatable::get_current_locale())
+    			);
+    		}
+            $fields->insertBefore($field, 'Title');
+        }
 
         $context->setFields($fields);
         $filters = array(
@@ -73,7 +94,8 @@ public function getSearchContext()
         $context->setFilters($filters);
 
         // Namespace fields, for easier detection if a search is present
-        foreach ($context->getFields() as $field) $field->setName(sprintf('q[%s]', $field->getName()));
+        foreach ($context->getFields() as $field)
+            if($field->getName() != 'locale') $field->setName(sprintf('q[%s]', $field->getName()));
         foreach ($context->getFilters() as $filter) $filter->setFullName(sprintf('q[%s]', $filter->getFullName()));
 
         return $context;
@@ -256,4 +278,4 @@ private function removeEmptyAttributes(SS_List $list, $type)
     }
 
 
-}
+}

javascript/SEOEditor.Translatable.js

@@ -0,0 +1,30 @@
+/**
+ * File: SEOEditor.Translatable.js
+ */
+(function($) {
+	$.entwine('ss', function($){
+        /**
+		 * whenever a new value is selected, reload the whole CMS in the new locale
+		 */
+		$('.SEOEditorAdmin #Form_SearchForm_locale').entwine({
+			onchange: function(e) {
+				// Get new locale code
+				locale = {locale: $(e.target).val()};
+
+				// Check existing url
+				search = /locale=[^&]*/;
+				url = document.location.href;
+				if(url.match(search)) {
+					// Replace locale code
+					url = url.replace(search, $.param(locale));
+				} else {
+					// Add locale code
+					url = $.path.addSearchParams(url, locale);
+				}
+				$('.cms-container').loadPanel(url);
+				return false;
+			}
+		});
+
+	});
+}(jQuery));

javascript/seo-editor.js

@@ -11,7 +11,14 @@
 
                 var $this = $(this);
                 var id = $this.closest('tr').attr('data-id');
-                var url = $this.closest('.ss-gridfield').attr('data-url') + "/update/" + id;
+                var preURL = $this.closest('.ss-gridfield').attr('data-url');
+                var url;
+
+                if(preURL.indexOf('?') != -1)
+                    url = preURL.substr(0, preURL.indexOf('?')) + "/update/" + id + preURL.substr(preURL.indexOf('?'));
+                else
+                    url = preURL + "/update/" + id;
+
                 var data = $this.attr('name') + '=' + $(this).val();
 
                 statusMessage('Saving changes', 'good');
@@ -40,4 +47,4 @@
 
     });
 
-}(jQuery));
+}(jQuery));