ENH add config for allowed_error_codes

README.md

@@ -49,6 +49,19 @@ SilverStripe\ErrorPage\ErrorPage:
   dev_append_error_message: false
 ```
 
+### Limiting optios in the CMS
+By default, all available error codes are present in the dropdown in the CMS. This can be overwhelming and there are a few (looking at you, 418) that can
+be confusing. To that end, you can limit the codes in the dropdown with the config value `allowed_error_codes` like so:
+
+```yml
+SilverStripe\ErrorPage\ErrorPage:
+  allowed_error_codes:
+    - 400
+    - 403
+    - 404
+    - 500
+```
+
 ## Reporting Issues
 
 Please [create an issue](http://github.com/silverstripe/silverstripe-errorpage/issues) for any bugs you've found, or features you're missing.

src/ErrorPage.php

@@ -38,19 +38,19 @@
  */
 class ErrorPage extends Page
 {
-    private static $db = array(
+    private static $db = [
         "ErrorCode" => "Int",
-    );
+    ];
 
-    private static $defaults = array(
+    private static $defaults = [
         "ShowInMenus" => 0,
         "ShowInSearch" => 0,
         "ErrorCode" => 400
-    );
+    ];
 
     private static $table_name = 'ErrorPage';
 
-    private static $allowed_children = array();
+    private static $allowed_children = [];
 
     private static $description = 'Custom content for different error cases (e.g. "Page not found")';
 
@@ -80,6 +80,15 @@ class ErrorPage extends Page
      */
     private static $store_filepath = null;
 
+    /**
+     * An array of error codes to allow in the CMS
+     * If unset, defaults to all available codes (see self::getCodes())
+     *
+     * @config
+     * @var ?array
+     */
+    private static $allowed_error_codes = null;
+
     /**
      * @param $member
      *
@@ -106,9 +115,9 @@ public static function response_for($statusCode, $errorMessage = null)
         // first attempt to dynamically generate the error page
         /** @var ErrorPage $errorPage */
         $errorPage = ErrorPage::get()
-            ->filter(array(
+            ->filter([
                 "ErrorCode" => $statusCode
-            ))->first();
+            ])->first();
 
         if ($errorPage) {
             Requirements::clear();
@@ -226,25 +235,25 @@ protected function requireDefaultRecordFixture($defaultData)
      */
     protected function getDefaultRecords()
     {
-        $data = array(
-            array(
+        $data = [
+            [
                 'ErrorCode' => 404,
                 'Title' => _t('SilverStripe\\ErrorPage\\ErrorPage.DEFAULTERRORPAGETITLE', 'Page not found'),
                 'Content' => _t(
                     'SilverStripe\\ErrorPage\\ErrorPage.DEFAULTERRORPAGECONTENT',
                     '<p>Sorry, it seems you were trying to access a page that doesn\'t exist.</p>'
                     . '<p>Please check the spelling of the URL you were trying to access and try again.</p>'
                 )
-            ),
-            array(
+            ],
+            [
                 'ErrorCode' => 500,
                 'Title' => _t('SilverStripe\\ErrorPage\\ErrorPage.DEFAULTSERVERERRORPAGETITLE', 'Server error'),
                 'Content' => _t(
                     'SilverStripe\\ErrorPage\\ErrorPage.DEFAULTSERVERERRORPAGECONTENT',
                     '<p>Sorry, there was a problem with handling your request.</p>'
                 )
-            )
-        );
+            ]
+        ];
 
         $this->extend('getDefaultRecords', $data);
 
@@ -384,7 +393,7 @@ public static function get_content_for_errorcode($statusCode)
 
     protected function getCodes()
     {
-        return [
+        $allCodes = [
             400 => _t('SilverStripe\\ErrorPage\\ErrorPage.CODE_400', '400 - Bad Request'),
             401 => _t('SilverStripe\\ErrorPage\\ErrorPage.CODE_401', '401 - Unauthorized'),
             402 => _t('SilverStripe\\ErrorPage\\ErrorPage.CODE_402', '402 - Payment Required'),
@@ -426,6 +435,13 @@ protected function getCodes()
             510 => _t('SilverStripe\\ErrorPage\\ErrorPage.CODE_510', '510 - Not Extended'),
             511 => _t('SilverStripe\\ErrorPage\\ErrorPage.CODE_511', '511 - Network Authentication Required'),
         ];
+
+        $allowedCodes = self::config()->get('allowed_error_codes');
+        if ($allowedCodes === null) {
+            return $allCodes;
+        }
+
+        return array_intersect_key($allCodes, array_flip($allowedCodes));
     }
 
     /**

tests/ErrorPageTest.php

@@ -14,6 +14,7 @@
 use SilverStripe\Core\Config\Config;
 use SilverStripe\Dev\FunctionalTest;
 use SilverStripe\ErrorPage\ErrorPage;
+use SilverStripe\ErrorPage\Tests\Fake\FakeErrorPage;
 use SilverStripe\ORM\DB;
 use SilverStripe\ORM\ValidationException;
 use SilverStripe\Versioned\Versioned;
@@ -40,6 +41,7 @@ protected function setUp(): void
         // Set temporary asset backend store
         TestAssetStore::activate('ErrorPageTest');
         Config::modify()->set(ErrorPage::class, 'enable_static_file', true);
+        Config::modify()->set(ErrorPage::class, 'allowed_error_codes', null);
         $this->logInWithPermission('ADMIN');
     }
 
@@ -283,4 +285,21 @@ public function testRequiredRecords()
         $this->expectOutputRegex('/.*500 error page refreshed.*/');
         ErrorPage::singleton()->requireDefaultRecords();
     }
+
+    public function testAllowedAllErrorCodes()
+    {
+        $page = $this->objFromFixture(FakeErrorPage::class, '418');
+        $allCodes = $page->codesForDropdown();
+        $this->assertCount(40, $allCodes);
+    }
+
+    public function testAllowedErrorCodes()
+    {
+        Config::modify()->set(ErrorPage::class, 'allowed_error_codes', [400, 500]);
+        $page = $this->objFromFixture(FakeErrorPage::class, '418');
+        $codes = $page->codesForDropdown();
+        $this->assertCount(2, $codes);
+        $this->assertArrayHasKey(400, $codes);
+        $this->assertArrayHasKey(500, $codes);
+    }
 }

tests/ErrorPageTest.yml

@@ -10,6 +10,13 @@ SilverStripe\ErrorPage\ErrorPage:
     Content: You do not have permission to view this page
     ErrorCode: 403
 
+SilverStripe\ErrorPage\Tests\Fake\FakeErrorPage:
+  418:
+    Title: "I'm a teapot"
+    URLSegment: im-a-teapot
+    Content: "I'm a teapot"
+    ErrorCode: 418
+
 SilverStripe\CMS\Model\SiteTree:
   home:
     Title: Home

tests/Fake/FakeErrorPage.php

@@ -0,0 +1,14 @@
+<?php
+
+namespace SilverStripe\ErrorPage\Tests\Fake;
+
+use SilverStripe\Dev\TestOnly;
+use SilverStripe\ErrorPage\ErrorPage;
+
+class FakeErrorPage extends ErrorPage implements TestOnly
+{
+    public function codesForDropdown()
+    {
+        return $this->getCodes();
+    }
+}