[FEATURE] CaseViewHelper for StandaloneFluid (#841)

CaseViewHelper doesn't have any dependencies to TYPO3,
it can be moved to Fluid Standalone.

src/ViewHelpers/Format/CaseViewHelper.php

@@ -0,0 +1,151 @@
+<?php
+
+declare(strict_types=1);
+
+/*
+ * This file belongs to the package "TYPO3 Fluid".
+ * See LICENSE.txt that was shipped with this package.
+ */
+
+namespace TYPO3Fluid\Fluid\ViewHelpers\Format;
+
+use TYPO3Fluid\Fluid\Core\Rendering\RenderingContextInterface;
+use TYPO3Fluid\Fluid\Core\ViewHelper\AbstractViewHelper;
+use TYPO3Fluid\Fluid\Core\ViewHelper\Exception;
+use TYPO3Fluid\Fluid\Core\ViewHelper\Traits\CompileWithRenderStatic;
+
+/**
+ * Modifies the case of an input string to upper- or lowercase or capitalization.
+ * The default transformation will be uppercase as in `mb_convert_case`_.
+ *
+ * Possible modes are:
+ *
+ * ``lower``
+ *   Transforms the input string to its lowercase representation
+ *
+ * ``upper``
+ *   Transforms the input string to its uppercase representation
+ *
+ * ``capital``
+ *   Transforms the input string to its first letter upper-cased, i.e. capitalization
+ *
+ * ``uncapital``
+ *   Transforms the input string to its first letter lower-cased, i.e. uncapitalization
+ *
+ * ``capitalWords``
+ *   Not supported yet: Transforms the input string to each containing word being capitalized
+ *
+ * Note that the behavior will be the same as in the appropriate PHP function `mb_convert_case`_;
+ * especially regarding locale and multibyte behavior.
+ *
+ * .. _mb_convert_case: https://www.php.net/manual/function.mb-convert-case.php
+ *
+ * Examples
+ * ========
+ *
+ * Default
+ * -------
+ *
+ * ::
+ *
+ *    <f:format.case>Some Text with miXed case</f:format.case>
+ *
+ * Output::
+ *
+ *    SOME TEXT WITH MIXED CASE
+ *
+ * Example with given mode
+ * -----------------------
+ *
+ * ::
+ *
+ *    <f:format.case mode="capital">someString</f:format.case>
+ *
+ * Output::
+ *
+ *    SomeString
+ */
+final class CaseViewHelper extends AbstractViewHelper
+{
+    use CompileWithRenderStatic;
+
+    /**
+     * Directs the input string being converted to "lowercase"
+     */
+    private const CASE_LOWER = 'lower';
+
+    /**
+     * Directs the input string being converted to "UPPERCASE"
+     */
+    private const CASE_UPPER = 'upper';
+
+    /**
+     * Directs the input string being converted to "Capital case"
+     */
+    private const CASE_CAPITAL = 'capital';
+
+    /**
+     * Directs the input string being converted to "unCapital case"
+     */
+    private const CASE_UNCAPITAL = 'uncapital';
+
+    /**
+     * Directs the input string being converted to "Capital Case For Each Word"
+     */
+    private const CASE_CAPITAL_WORDS = 'capitalWords';
+
+    /**
+     * Output is escaped already. We must not escape children, to avoid double encoding.
+     *
+     * @var bool
+     */
+    protected $escapeChildren = false;
+
+    public function initializeArguments(): void
+    {
+        $this->registerArgument('value', 'string', 'The input value. If not given, the evaluated child nodes will be used.', false);
+        $this->registerArgument('mode', 'string', 'The case to apply, must be one of this\' CASE_* constants. Defaults to uppercase application.', false, self::CASE_UPPER);
+    }
+
+    /**
+     * Changes the case of the input string
+     * @throws Exception
+     */
+    public static function renderStatic(array $arguments, \Closure $renderChildrenClosure, RenderingContextInterface $renderingContext): string
+    {
+        $value = $arguments['value'];
+        $mode = $arguments['mode'];
+
+        if ($value === null) {
+            $value = (string)$renderChildrenClosure();
+        }
+
+        switch ($mode) {
+            case self::CASE_LOWER:
+                $output = mb_strtolower($value, 'utf-8');
+                break;
+            case self::CASE_UPPER:
+                $output = mb_strtoupper($value, 'utf-8');
+                break;
+            case self::CASE_CAPITAL:
+                $firstChar = mb_substr($value, 0, 1, 'utf-8');
+                $firstChar = mb_strtoupper($firstChar, 'utf-8');
+                $remainder = mb_substr($value, 1, null, 'utf-8');
+                $output = $firstChar . $remainder;
+                break;
+            case self::CASE_UNCAPITAL:
+                $firstChar = mb_substr($value, 0, 1, 'utf-8');
+                $firstChar = mb_strtolower($firstChar, 'utf-8');
+                $remainder = mb_substr($value, 1, null, 'utf-8');
+                $output = $firstChar . $remainder;
+                break;
+            case self::CASE_CAPITAL_WORDS:
+                $output = mb_convert_case($value, MB_CASE_TITLE, 'utf-8');
+                break;
+            default:
+                throw new Exception('The case mode "' . $mode . '" supplied to Fluid\'s format.case ViewHelper is not supported.', 1358349150);
+        }
+
+        return $output;
+    }
+}

tests/Functional/ViewHelpers/Format/CaseViewHelperTest.php

@@ -0,0 +1,96 @@
+<?php
+
+declare(strict_types=1);
+
+/*
+ * This file belongs to the package "TYPO3 Fluid".
+ * See LICENSE.txt that was shipped with this package.
+ */
+
+namespace TYPO3Fluid\Fluid\Tests\Functional\ViewHelpers\Format;
+
+use TYPO3Fluid\Fluid\Core\ViewHelper\Exception;
+use TYPO3Fluid\Fluid\Tests\Functional\AbstractFunctionalTestCase;
+use TYPO3Fluid\Fluid\View\TemplateView;
+
+final class CaseViewHelperTest extends AbstractFunctionalTestCase
+{
+    public static function renderConvertsAValueDataProvider(): array
+    {
+        return [
+            'empty value' => [
+                '<f:format.case value="" />',
+                '',
+            ],
+            'value from child, uppercase default' => [
+                '<f:format.case>foob4r</f:format.case>',
+                'FOOB4R',
+            ],
+            'simple value' => [
+                '<f:format.case value="foo" />',
+                'FOO',
+            ],
+            'mode lower' => [
+                '<f:format.case value="FooB4r" mode="lower" />',
+                'foob4r',
+            ],
+            'mode upper' => [
+                '<f:format.case value="FooB4r" mode="upper" />',
+                'FOOB4R',
+            ],
+            'mode capital' => [
+                '<f:format.case value="foo bar" mode="capital" />',
+                'Foo bar',
+            ],
+            'mode uncapital' => [
+                '<f:format.case value="FOO Bar" mode="uncapital" />',
+                'fOO Bar',
+            ],
+            'special chars 1' => [
+                '<f:format.case value="smørrebrød" mode="upper" />',
+                'SMØRREBRØD',
+            ],
+            'special chars 2' => [
+                '<f:format.case value="smørrebrød" mode="capital" />',
+                'Smørrebrød',
+            ],
+            'special chars 3' => [
+                '<f:format.case value="römtömtömtöm" mode="upper" />',
+                'RÖMTÖMTÖMTÖM',
+            ],
+            'special chars 4' => [
+                '<f:format.case value="Ἕλλάς α ω" mode="upper" />',
+                'ἝΛΛΆΣ Α Ω',
+            ],
+        ];
+    }
+
+    /**
+     * @test
+     * @dataProvider renderConvertsAValueDataProvider
+     */
+    public function renderConvertsAValue(string $template, string $expected): void
+    {
+        $view = new TemplateView();
+        $view->getRenderingContext()->setCache(self::$cache);
+        $view->getRenderingContext()->getTemplatePaths()->setTemplateSource($template);
+        self::assertSame($expected, $view->render());
+
+        $view = new TemplateView();
+        $view->getRenderingContext()->setCache(self::$cache);
+        $view->getRenderingContext()->getTemplatePaths()->setTemplateSource($template);
+        self::assertSame($expected, $view->render());
+    }
+
+    /**
+     * @test
+     */
+    public function viewHelperThrowsExceptionIfIncorrectModeIsGiven(): void
+    {
+        $this->expectException(Exception::class);
+        $this->expectExceptionCode(1358349150);
+        $view = new TemplateView();
+        $view->getRenderingContext()->getTemplatePaths()->setTemplateSource('<f:format.case value="foo" mode="invalid" />');
+        $view->render();
+    }
+}