[!!!][TASK] Remove language related JavaScript files

The "language" extension has two JavaScript files left:

- Typo3Lang.js, was required for ExtJS, which has been removed
some time ago.
- Lang.js, is a RequireJS module that mimics the behavior of Typo3Lang.

As the desired functionality may be achieved with plain PHP, the module
is rendered obsolete and gets removed.

Resolves: #84148
Releases: master
Change-Id: Ice3df96195bb435da8df1004d1e9304ec7601d26
Reviewed-on: https://review.typo3.org/56023
Tested-by: TYPO3com <no-reply@typo3.com>
Reviewed-by: Mathias Schreiber <mathias.schreiber@typo3.com>
Tested-by: Mathias Schreiber <mathias.schreiber@typo3.com>
Reviewed-by: Benni Mack <benni@typo3.org>
Tested-by: Benni Mack <benni@typo3.org>

Build/tsconfig.json

@@ -50,10 +50,6 @@
                 "../typo3/sysext/install/Resources/Public/JavaScript/*",
                 "../typo3/sysext/install/Resources/Private/TypeScript/*"
             ],
-            "TYPO3/CMS/Lang/*": [
-                "../typo3/sysext/lang/Resources/Public/JavaScript/*",
-                "../typo3/sysext/lang/Resources/Private/TypeScript/*"
-            ],
             "TYPO3/CMS/Linkvalidator/*": [
                 "../typo3/sysext/linkvalidator/Resources/Public/JavaScript/*",
                 "../typo3/sysext/linkvalidator/Resources/Private/TypeScript/*"

typo3/sysext/backend/Resources/Public/JavaScript/PageTree/PageTreeToolbar.js

@@ -19,8 +19,7 @@ define(['jquery',
     'd3',
     'TYPO3/CMS/Backend/PageTree/PageTreeDragDrop',
     'TYPO3/CMS/Backend/Tooltip',
-    'TYPO3/CMS/Backend/SvgTree',
-    'TYPO3/CMS/Lang/Lang'
+    'TYPO3/CMS/Backend/SvgTree'
   ],
   function($, Icons, d3, PageTreeDragDrop) {
     'use strict';

typo3/sysext/backend/Resources/Public/JavaScript/SvgTree.js

@@ -22,8 +22,7 @@ define(
     'TYPO3/CMS/Backend/Modal',
     'TYPO3/CMS/Backend/Severity',
     'TYPO3/CMS/Backend/Notification',
-    'TYPO3/CMS/Backend/Icons',
-    'TYPO3/CMS/Lang/Lang'
+    'TYPO3/CMS/Backend/Icons'
   ],
   function($, d3, ContextMenu, Modal, Severity, Notification, Icons) {
     'use strict';

typo3/sysext/core/Classes/Page/PageRenderer.php

@@ -1887,22 +1887,46 @@ protected function renderMainJavaScriptLibraries()
         if (TYPO3_MODE === 'BE') {
             $this->addAjaxUrlsToInlineSettings();
         }
-        $inlineSettings = $this->inlineLanguageLabels ? 'TYPO3.lang = ' . json_encode($this->inlineLanguageLabels) . ';' : '';
+        $inlineSettings = '';
+        $languageLabels = $this->parseLanguageLabelsForJavaScript();
+        if (!empty($languageLabels)) {
+            $inlineSettings .= 'TYPO3.lang = ' . json_encode($languageLabels) . ';';
+        }
         $inlineSettings .= $this->inlineSettings ? 'TYPO3.settings = ' . json_encode($this->inlineSettings) . ';' : '';
 
         if ($inlineSettings !== '') {
             // make sure the global TYPO3 is available
             $inlineSettings = 'var TYPO3 = TYPO3 || {};' . CRLF . $inlineSettings;
             $out .= $this->inlineJavascriptWrap[0] . $inlineSettings . $this->inlineJavascriptWrap[1];
-            // Add language module only if also jquery is guaranteed to be there
-            if (TYPO3_MODE === 'BE' && !empty($this->jQueryVersions)) {
-                $this->loadRequireJsModule('TYPO3/CMS/Lang/Lang');
-            }
         }
 
         return $out;
     }
 
+    /**
+     * Converts the language labels for usage in JavaScript
+     *
+     * @return array
+     */
+    protected function parseLanguageLabelsForJavaScript(): array
+    {
+        if (empty($this->inlineLanguageLabels)) {
+            return [];
+        }
+
+        $labels = [];
+        foreach ($this->inlineLanguageLabels as $key => $translationUnit) {
+            if (is_array($translationUnit)) {
+                $translationUnit = current($translationUnit);
+                $labels[$key] = $translationUnit['target'] ?? $translationUnit['source'];
+            } else {
+                $labels[$key] = $translationUnit;
+            }
+        }
+
+        return $labels;
+    }
+
     /**
      * Load the language strings into JavaScript
      */

typo3/sysext/core/Documentation/Changelog/master/Breaking-84148-RequireJSModuleForLanguageHandlingRemoved.rst

@@ -0,0 +1,33 @@
+.. include:: ../../Includes.txt
+
+=================================================================
+Breaking: #84148 - RequireJS module for language handling removed
+=================================================================
+
+See :issue:`84148`
+
+Description
+===========
+
+Since the removal of ExtJS, the JavaScript files that handle the localization of labels in backend modules became obsolete and are removed.
+
+
+Impact
+======
+
+Depending on the RequireJS module :js:`TYPO3/CMS/Lang/Lang` will result in `404` errors, as the module has been removed.
+
+
+Affected Installations
+======================
+
+Every 3rd party extension depending on :js:`TYPO3/CMS/Lang/Lang` is affected.
+
+
+Migration
+=========
+
+Remove the module from the affected RequireJS modules. The labels are now prepared by the PageRenderer and passed
+to :js:`TYPO3.lang` without the need of additional JavaScript.
+
+.. index:: Backend, JavaScript, NotScanned

typo3/sysext/core/Tests/Unit/Page/PageRendererTest.php

@@ -311,4 +311,48 @@ public function unsetAddedMetaTag()
         $expectedResult = [];
         $this->assertSame($expectedResult, $actualResult);
     }
+
+    /**
+     * @test
+     */
+    public function parseLanguageLabelsForJavaScriptReturnsEmptyStringIfEmpty()
+    {
+        $subject = $this->getAccessibleMock(\TYPO3\CMS\Core\Page\PageRenderer::class, ['dummy'], [], '', false);
+        $inlineLanguageLabels = [];
+        $subject->_set('inlineLanguageLabels', $inlineLanguageLabels);
+        $actual = $subject->_call('parseLanguageLabelsForJavaScript');
+        $this->assertEmpty($actual);
+    }
+
+    /**
+     * @test
+     */
+    public function parseLanguageLabelsForJavaScriptReturnsFlatArray()
+    {
+        $subject = $this->getAccessibleMock(\TYPO3\CMS\Core\Page\PageRenderer::class, ['dummy'], [], '', false);
+        $inlineLanguageLabels = [
+            'key' => 'label',
+            'foo' => 'bar',
+            'husel' => [
+                [
+                    'source' => 'pusel',
+                ]
+            ],
+            'hello' => [
+                [
+                    'source' => 'world',
+                    'target' => 'welt',
+                ]
+            ],
+        ];
+        $subject->_set('inlineLanguageLabels', $inlineLanguageLabels);
+        $expected = [
+            'key' => 'label',
+            'foo' => 'bar',
+            'husel' => 'pusel',
+            'hello' => 'welt',
+        ];
+        $actual = $subject->_call('parseLanguageLabelsForJavaScript');
+        $this->assertSame($expected, $actual);
+    }
 }