feature symfony#60355 [Serializer] Add CDATA_WRAPPING_NAME_PATTERN support to XmlEncoder (Maximilian Ruta)

This PR was merged into the 7.4 branch.

Discussion
----------

[Serializer] Add `CDATA_WRAPPING_NAME_PATTERN` support to `XmlEncoder`

| Q             | A
| ------------- | ---
| Branch?       | 7.3
| Bug fix?      | no
| New feature?  | yes
| Deprecations? | no
| Issues        |
| License       | MIT

### Add `CDATA_WRAPPING_NAME_PATTERN` support to XmlEncoder

This PR introduces a new option for the Symfony Serializer component's `XmlEncoder`: `CDATA_WRAPPING_NAME_PATTERN`.

While Symfony already provides `CDATA_WRAPPING_PATTERN` to wrap field *content* in CDATA based on a regex match, this new feature enables CDATA wrapping based on the **field name**—regardless of the field's content.

**Example use case:**

```php
$this->encoder->encode($data, 'xml', [
    XmlEncoder::CDATA_WRAPPING_NAME_PATTERN => '(firstname|lastname)'
]);
```

This ensures that fields named `firstname` or `lastname` are always wrapped in CDATA tags, even if their content doesn't match the typical pattern used by `CDATA_WRAPPING_PATTERN`.

### Motivation:

* **Consistent Output**: In many integration scenarios (e.g., with legacy systems, XML consumers, or strict XSD schemas), consumers expect certain fields to **always** use CDATA sections—even when their content doesn't require escaping. This option allows for deterministic XML output by name.

* **Better Control**: It separates concerns: one can now configure CDATA-wrapping for *content-based* needs and *field-based* policies independently.

* **Backward Compatible**: The feature is fully optional and does not interfere with existing behavior unless the option is explicitly set.

Commits
-------

c4f363c [Serializer] Add CDATA_WRAPPING_NAME_PATTERN support to XmlEncoder

Author: fabpot

src/Symfony/Component/Serializer/Encoder/XmlEncoder.php

@@ -59,6 +59,7 @@ class XmlEncoder implements EncoderInterface, DecoderInterface, NormalizationAwa
     public const TYPE_CAST_ATTRIBUTES = 'xml_type_cast_attributes';
     public const VERSION = 'xml_version';
     public const CDATA_WRAPPING = 'cdata_wrapping';
+    public const CDATA_WRAPPING_NAME_PATTERN = 'cdata_wrapping_name_pattern';
     public const CDATA_WRAPPING_PATTERN = 'cdata_wrapping_pattern';
     public const IGNORE_EMPTY_ATTRIBUTES = 'ignore_empty_attributes';
 
@@ -72,6 +73,7 @@ class XmlEncoder implements EncoderInterface, DecoderInterface, NormalizationAwa
         self::ROOT_NODE_NAME => 'response',
         self::TYPE_CAST_ATTRIBUTES => true,
         self::CDATA_WRAPPING => true,
+        self::CDATA_WRAPPING_NAME_PATTERN => false,
         self::CDATA_WRAPPING_PATTERN => '/[<>&]/',
         self::IGNORE_EMPTY_ATTRIBUTES => false,
     ];
@@ -440,10 +442,15 @@ private function appendNode(\DOMNode $parentNode, mixed $data, string $format, a
 
     /**
      * Checks if a value contains any characters which would require CDATA wrapping.
+     *
+     * @param array<string, mixed> $context
      */
-    private function needsCdataWrapping(string $val, array $context): bool
+    private function needsCdataWrapping(string $name, string $val, array $context): bool
     {
-        return ($context[self::CDATA_WRAPPING] ?? $this->defaultContext[self::CDATA_WRAPPING]) && preg_match($context[self::CDATA_WRAPPING_PATTERN] ?? $this->defaultContext[self::CDATA_WRAPPING_PATTERN], $val);
+        return ($context[self::CDATA_WRAPPING] ?? $this->defaultContext[self::CDATA_WRAPPING])
+                && (preg_match($context[self::CDATA_WRAPPING_PATTERN] ?? $this->defaultContext[self::CDATA_WRAPPING_PATTERN], $val)
+                || (($context[self::CDATA_WRAPPING_NAME_PATTERN] ?? $this->defaultContext[self::CDATA_WRAPPING_NAME_PATTERN]) && preg_match($context[self::CDATA_WRAPPING_NAME_PATTERN] ?? $this->defaultContext[self::CDATA_WRAPPING_NAME_PATTERN], $name))
+                );
     }
 
     /**
@@ -471,7 +478,7 @@ private function selectNodeType(\DOMNode $node, mixed $val, string $format, arra
             return $this->selectNodeType($node, $this->serializer->normalize($val, $format, $context), $format, $context);
         } elseif (is_numeric($val)) {
             return $this->appendText($node, (string) $val);
-        } elseif (\is_string($val) && $this->needsCdataWrapping($val, $context)) {
+        } elseif (\is_string($val) && $this->needsCdataWrapping($node->nodeName, $val, $context)) {
             return $this->appendCData($node, $val);
         } elseif (\is_string($val)) {
             return $this->appendText($node, $val);

src/Symfony/Component/Serializer/Tests/Encoder/XmlEncoderTest.php

@@ -568,6 +568,23 @@ public function testDecodeXMLWithProcessInstruction()
         $this->assertEquals(get_object_vars($obj), $this->encoder->decode($source, 'xml'));
     }
 
+    public function testCDataNamePattern()
+    {
+        $expected = <<<'XML'
+<?xml version="1.0"?>
+<response><person><firstname><![CDATA[Benjamin]]></firstname><lastname><![CDATA[Alexandre]]></lastname><other>data</other></person><person><firstname><![CDATA[Damien]]></firstname><lastname><![CDATA[Clay]]></lastname><other>data</other></person></response>
+
+XML;
+        $source = ['person' => [
+            ['firstname' => 'Benjamin', 'lastname' => 'Alexandre', 'other' => 'data'],
+            ['firstname' => 'Damien', 'lastname' => 'Clay', 'other' => 'data'],
+        ]];
+
+        $this->assertEquals($expected, $this->encoder->encode($source, 'xml', [
+            XmlEncoder::CDATA_WRAPPING_NAME_PATTERN => '/(firstname|lastname)/',
+        ]));
+    }
+
     public function testDecodeIgnoreWhiteSpace()
     {
         $source = <<<'XML'