FIX Update API changes in ErrorPage and typo in extension config class name

_config/extensions.yml

@@ -28,7 +28,7 @@ SilverStripe\Assets\File:
   extensions:
     - SilverStripe\Subsites\Extensions\FileSubsites
 
-SilverStripe\CMS\Model\ErrorPage:
+SilverStripe\ErrorPage\ErrorPage:
   extensions:
     - SilverStripe\Subsites\Extensions\ErrorPageSubsite
 

code/extensions/ErrorPageSubsite.php

@@ -11,17 +11,19 @@ use SilverStripe\Subsites\Model\Subsite;
 class ErrorPageSubsite extends DataExtension
 {
     /**
-     * Alter file path to generated a static (static) error page file to handle error page template on different sub-sites
+     * Alter file path to generated a static (static) error page file to handle error page template
+     * on different sub-sites
      *
-     * @see Error::get_filepath_for_errorcode()
+     * @see ErrorPage::get_error_filename()
      *
-     * FIXME since {@link Subsite::currentSubsite()} partly relies on Session, viewing other sub-site (including main site) between
-     * opening ErrorPage in the CMS and publish ErrorPage causes static error page to get generated incorrectly.
-     * @param $statusCode
-     * @param null $locale
-     * @return string
+     * FIXME since {@link Subsite::currentSubsite()} partly relies on Session, viewing other sub-site (including
+     * main site) between opening ErrorPage in the CMS and publish ErrorPage causes static error page to get
+     * generated incorrectly.
+     *
+     * @param string $name
+     * @param int $statusCode
      */
-    public function alternateFilepathForErrorcode($statusCode, $locale = null)
+    public function updateErrorFilename(&$name, &$statusCode)
     {
         $static_filepath = Config::inst()->get($this->owner->ClassName, 'static_filepath');
         $subdomainPart = '';
@@ -29,7 +31,8 @@ class ErrorPageSubsite extends DataExtension
         // Try to get current subsite from session
         $subsite = Subsite::currentSubsite();
 
-        // since this function is called from Page class before the controller is created, we have to get subsite from domain instead
+        // since this function is called from Page class before the controller is created, we have
+        // to get subsite from domain instead
         if (!$subsite) {
             $subsiteID = Subsite::getSubsiteIDForDomain();
             if ($subsiteID != 0) {
@@ -44,12 +47,16 @@ class ErrorPageSubsite extends DataExtension
             $subdomainPart = "-{$subdomain}";
         }
 
-        if (singleton(SiteTree::class)->hasExtension('Translatable') && $locale && $locale != Translatable::default_locale()) {
+        // @todo implement Translatable namespace
+        if (singleton(SiteTree::class)->hasExtension('Translatable')
+            && $locale
+            && $locale != Translatable::default_locale()
+        ) {
             $filepath = $static_filepath . "/error-{$statusCode}-{$locale}{$subdomainPart}.html";
         } else {
             $filepath = $static_filepath . "/error-{$statusCode}{$subdomainPart}.html";
         }
 
-        return $filepath;
+        $name = $filepath;
     }
 }

code/extensions/SiteTreeSubsites.php

@@ -469,7 +469,7 @@ class SiteTreeSubsites extends DataExtension
         if ($subsite && $subsite->exists() && $subsite->PageTypeBlacklist) {
             $blacklisted = explode(',', $subsite->PageTypeBlacklist);
             // All subclasses need to be listed explicitly
-            if (in_array($this->owner->class, $blacklisted)) {
+            if (in_array(get_class($this->owner), $blacklisted)) {
                 return false;
             }
         }

tests/php/SiteTreeSubsitesTest.php

@@ -82,12 +82,10 @@ class SiteTreeSubsitesTest extends BaseSubsiteTest
 
     public function testErrorPageLocations()
     {
-        $this->markTestSkipped('needs refactoring');
-
         $subsite1 = $this->objFromFixture(Subsite::class, 'domaintest1');
 
         Subsite::changeSubsite($subsite1->ID);
-        $path = ErrorPage::get_filepath_for_errorcode(500);
+        $path = TestErrorPage::get_error_filename_spy(500);
 
         $static_path = Config::inst()->get(ErrorPage::class, 'static_filepath');
         $expected_path = $static_path . '/error-500-' . $subsite1->domain() . '.html';