[!!!][TASK] Remove "sys_template.nextLevel"

The special handling "nextLevel" in TypoScript templates
to only load a specific sys_template on the next level (subpages and
further down the rootline) but not on the current level,
is removed.

It is recommended to use proper inclusions and TypoScript
conditions instead.

This reduces complexity within the TemplateService parser,
and for newcomers a very confusing option after gathering
some feedback on this topic.

The database field "sys_template.nextLevel" is therefore
removed.

Resolves: #88640
Releases: master
Change-Id: I06e14d6dfbde82eb36f2ffc30b61bd9870906246
Reviewed-on: https://review.typo3.org/c/Packages/TYPO3.CMS/+/61158
Tested-by: TYPO3com <noreply@typo3.com>
Tested-by: Andreas Fernandez <a.fernandez@scripting-base.de>
Tested-by: Daniel Goerz <daniel.goerz@posteo.de>
Reviewed-by: Benjamin Kott <benjamin.kott@outlook.com>
Reviewed-by: Andreas Fernandez <a.fernandez@scripting-base.de>
Reviewed-by: Daniel Goerz <daniel.goerz@posteo.de>

typo3/sysext/core/Classes/TypoScript/ExtendedTemplateService.php

@@ -679,7 +679,6 @@ public function ext_getTemplateHierarchyArr($arr, $depthData, $keyArray, $first
 							<td align="center">' . ($row['clConst'] ? $statusCheckedIcon : '') . '</td>
 							<td align="center">' . ($row['pid'] ?: '') . '</td>
 							<td align="center">' . ($RL >= 0 ? $RL : '') . '</td>
-							<td>' . ($row['next'] ? $row['next'] : '') . '</td>
 						</tr>';
             if ($deeper) {
                 $keyArray = $this->ext_getTemplateHierarchyArr($arr[$key . '.'], $depthData . ($first ? '' : '<span class="treeline-icon treeline-icon-' . $LN . '"></span>'), $keyArray);

typo3/sysext/core/Classes/TypoScript/TemplateService.php

@@ -159,13 +159,6 @@ class TemplateService
      */
     protected $hierarchyInfoToRoot = [];
 
-    /**
-     * Next-level flag (see runThroughTemplates())
-     *
-     * @var int
-     */
-    protected $nextLevel = 0;
-
     /**
      * The Page UID of the root page
      *
@@ -535,28 +528,6 @@ public function runThroughTemplates($theRootLine, $start_template_uid = 0)
         $c = count($this->absoluteRootLine);
         $queryBuilder = GeneralUtility::makeInstance(ConnectionPool::class)->getQueryBuilderForTable('sys_template');
         for ($a = 0; $a < $c; $a++) {
-            // If some template loaded before has set a template-id for the next level, then load this template first!
-            if ($this->nextLevel) {
-                $queryBuilder->setRestrictions($this->queryBuilderRestrictions);
-                $queryResult = $queryBuilder
-                    ->select('*')
-                    ->from('sys_template')
-                    ->where(
-                        $queryBuilder->expr()->eq(
-                            'uid',
-                            $queryBuilder->createNamedParameter($this->nextLevel, \PDO::PARAM_INT)
-                        )
-                    )
-                    ->execute();
-                $this->nextLevel = 0;
-                if ($row = $queryResult->fetch()) {
-                    $this->versionOL($row);
-                    if (is_array($row)) {
-                        $this->processTemplate($row, 'sys_' . $row['uid'], $this->absoluteRootLine[$a]['uid'], 'sys_' . $row['uid']);
-                    }
-                }
-            }
-
             $where = [
                 $queryBuilder->expr()->eq(
                     'pid',
@@ -702,7 +673,6 @@ public function processTemplate($row, $idList, $pid, $templateID = '', $template
         // Creating hierarchy information; Used by backend analysis tools
         $this->hierarchyInfo[] = ($this->hierarchyInfoToRoot[] = [
             'root' => trim($row['root'] ?? ''),
-            'next' => $row['nextLevel'] ?? null,
             'clConst' => $clConst,
             'clConf' => $clConf,
             'templateID' => $templateID,
@@ -727,12 +697,6 @@ public function processTemplate($row, $idList, $pid, $templateID = '', $template
             $this->rootId = $pid;
             $this->rootLine = [];
         }
-        // If a template is set to be active on the next level set this internal value to point to this UID. (See runThroughTemplates())
-        if ($row['nextLevel'] ?? null) {
-            $this->nextLevel = $row['nextLevel'];
-        } else {
-            $this->nextLevel = 0;
-        }
     }
 
     /**
@@ -1240,7 +1204,6 @@ protected function addDefaultTypoScript()
             $rootTemplateId = $this->hierarchyInfo[count($this->hierarchyInfo) - 1]['templateID'] ?? null;
             $defaultTemplateInfo = [
                 'root' => '',
-                'next' => '',
                 'clConst' => '',
                 'clConf' => '',
                 'templateID' => '_defaultTypoScript_',

typo3/sysext/core/Documentation/Changelog/master/Breaking-88640-DatabaseFieldSys_templatenextLevelAndTypoScriptSublevel-InheritanceRemoved.rst

@@ -0,0 +1,49 @@
+.. include:: ../../Includes.txt
+
+========================================================================================================
+Breaking: #88640 - Database field "sys_template.nextLevel" and TypoScript sublevel - inheritance removed
+========================================================================================================
+
+See :issue:`88640`
+
+Description
+===========
+
+The database field `nextLevel` of the database table `sys_template` where TypoScript configuration
+is stored, has been removed.
+
+The field `nextLevel` was introduced in TYPO3 v3.x before TypoScript could be imported from
+external files.
+
+Nowadays, TypoScript conditions should be used much more instead of this `nextLevel` feature,
+which is kind of a pseudo-condition.
+
+
+Impact
+======
+
+The database field is removed, and not evaluated anymore in TypoScript compilation.
+
+Requesting the database field in custom database queries will result in an SQL error.
+
+
+Affected Installations
+======================
+
+TYPO3 installations that have `sys_template` records with this flag activated,
+or querying this database field in third-party extensions.
+
+
+Migration
+=========
+
+Check for existing `sys_template` records having this flag activated by executing
+this SQL command:
+
+:sql:`SELECT * FROM sys_template WHERE nextLevel>0 AND deleted=0;`
+
+before updating TYPO3 Core.
+
+Replace the sys_template record (the uid of the record is stored in the "nextLevel" field) with a condition e.g. :ts:`[tree.level > 1]` to add TypoScript for subpages.
+
+.. index:: Database, NotScanned

typo3/sysext/frontend/Configuration/TCA/sys_template.php

@@ -27,7 +27,7 @@
         'searchFields' => 'title,constants,config'
     ],
     'interface' => [
-        'showRecordFieldList' => 'title,clear,root,basedOn,nextLevel,sitetitle,description,hidden,starttime,endtime'
+        'showRecordFieldList' => 'title,clear,root,basedOn,sitetitle,description,hidden,starttime,endtime'
     ],
     'columns' => [
         'title' => [
@@ -123,18 +123,6 @@
                 'softref' => 'email[subst],url[subst]'
             ],
         ],
-        'nextLevel' => [
-            'label' => 'LLL:EXT:frontend/Resources/Private/Language/locallang_tca.xlf:sys_template.nextLevel',
-            'config' => [
-                'type' => 'group',
-                'internal_type' => 'db',
-                'allowed' => 'sys_template',
-                'size' => 1,
-                'maxitems' => 1,
-                'minitems' => 0,
-                'default' => '',
-            ]
-        ],
         'include_static_file' => [
             'label' => 'LLL:EXT:frontend/Resources/Private/Language/locallang_tca.xlf:sys_template.include_static_file',
             'config' => [
@@ -229,7 +217,7 @@
             --div--;LLL:EXT:core/Resources/Private/Language/Form/locallang_tabs.xlf:general,
                 title, sitetitle, constants, config,
             --div--;LLL:EXT:frontend/Resources/Private/Language/locallang_tca.xlf:sys_template.tabs.options,
-                clear, root, nextLevel,
+                clear, root,
             --div--;LLL:EXT:frontend/Resources/Private/Language/locallang_tca.xlf:sys_template.tabs.include,
                 includeStaticAfterBasedOn, include_static_file, basedOn, static_file_mode,
             --div--;LLL:EXT:core/Resources/Private/Language/Form/locallang_tabs.xlf:access,

typo3/sysext/frontend/Resources/Private/Language/locallang_tca.xlf

@@ -489,9 +489,6 @@
 			<trans-unit id="sys_template.resources">
 				<source>Resources</source>
 			</trans-unit>
-			<trans-unit id="sys_template.nextLevel">
-				<source>Template on Next Level</source>
-			</trans-unit>
 			<trans-unit id="sys_template.include_static_file">
 				<source>Include static (from extensions)</source>
 			</trans-unit>

typo3/sysext/frontend/Tests/Functional/Tca/TemplateVisibleFieldsTest.php

@@ -29,7 +29,6 @@ class TemplateVisibleFieldsTest extends \TYPO3\TestingFramework\Core\Functional\
         'description',
         'clear',
         'root',
-        'nextLevel',
         'includeStaticAfterBasedOn',
         'include_static_file',
         'basedOn',

typo3/sysext/frontend/ext_tables.sql

@@ -82,7 +82,6 @@ CREATE TABLE sys_template (
 	include_static_file text,
 	constants text,
 	config text,
-	nextLevel varchar(5) DEFAULT '' NOT NULL,
 	basedOn tinytext,
 	includeStaticAfterBasedOn tinyint(4) unsigned DEFAULT '0' NOT NULL,
 	static_file_mode tinyint(4) unsigned DEFAULT '0' NOT NULL,

typo3/sysext/tstemplate/Resources/Private/Language/locallang_analyzer.xlf

@@ -24,9 +24,6 @@
 			<trans-unit id="rootline">
 				<source>Rootline</source>
 			</trans-unit>
-			<trans-unit id="nextLevel">
-				<source>Next Level</source>
-			</trans-unit>
 			<trans-unit id="templateHierarchy">
 				<source>Template hierarchy</source>
 			</trans-unit>

typo3/sysext/tstemplate/Resources/Private/Templates/TemplateAnalyzerModuleFunction.html

@@ -23,7 +23,6 @@ <h2><f:translate key="{LLPrefix}templateHierarchy"/></h2>
                 <th><f:translate key="{LLPrefix}clearConstants"/></th>
                 <th><f:translate key="{LLPrefix}pid"/></th>
                 <th><f:translate key="{LLPrefix}rootline"/></th>
-                <th><f:translate key="{LLPrefix}nextLevel"/></th>
             </tr>
         </thead>
         <f:format.raw>{hierarchy}</f:format.raw>