Conver null based on option (#226)

* Convert null to xsi:nil based on setting

* Update ArrayToXml.php

* Update ArrayToXml.php

* Update ArrayToXmlTest__it_can_convert_an_array_with_empty_string_and_null_value_to_xml__1.xml

* Update ArrayToXml.php

Author: radeno

src/ArrayToXml.php

@@ -19,6 +19,8 @@ class ArrayToXml
 
     protected string $numericTagNamePrefix = 'numeric_';
 
+    protected array $options = ['convertNullToXsiNil' => false];
+
     public function __construct(
         array $array,
         string | array $rootElement = '',
@@ -27,7 +29,8 @@ public function __construct(
         string $xmlVersion = '1.0',
         array $domProperties = [],
         bool | null $xmlStandalone = null,
-        bool $addXmlDeclaration = true
+        bool $addXmlDeclaration = true,
+        array | null $options = ['convertNullToXsiNil' => false]
     ) {
         $this->document = new DOMDocument($xmlVersion, $xmlEncoding ?? '');
 
@@ -41,6 +44,8 @@ public function __construct(
 
         $this->addXmlDeclaration = $addXmlDeclaration;
 
+        $this->options = array_merge($this->options, $options);
+
         $this->replaceSpacesByUnderScoresInKeyNames = $replaceSpacesByUnderScoresInKeyNames;
 
         if (! empty($array) && $this->isArrayAllKeySequential($array)) {
@@ -68,6 +73,7 @@ public static function convert(
         array $domProperties = [],
         bool $xmlStandalone = null,
         bool $addXmlDeclaration = true,
+        array $options = ['convertNullToXsiNil' => false]
     ): string {
         $converter = new static(
             $array,
@@ -77,7 +83,8 @@ public static function convert(
             $xmlVersion,
             $domProperties,
             $xmlStandalone,
-            $addXmlDeclaration
+            $addXmlDeclaration,
+            $options
         );
 
         return $converter->toXml();
@@ -211,7 +218,7 @@ protected function addNode(DOMElement $element, string $key, mixed $value): void
 
     protected function addNodeTypeAttribute(DOMElement $element, mixed $value): void
     {
-        if (is_null($value)) {
+        if ($this->options['convertNullToXsiNil'] && is_null($value)) {
             if (! $this->rootNode->hasAttribute('xmlns:xsi')) {
                 $this->rootNode->setAttribute('xmlns:xsi', 'http://www.w3.org/2001/XMLSchema-instance');
             }

tests/ArrayToXmlTest.php

@@ -480,6 +480,15 @@
     assertMatchesSnapshot($arrayToXml->dropXmlDeclaration()->toXml());
 });
 
+it('can convert an array with empty string and null value to xml with option', function () {
+    $arr = [
+        'testString' => '',
+        'testNull' => null,
+    ];
+
+    assertMatchesXmlSnapshot(ArrayToXml::convert($arr, '', true, null, '1.0', [], null, true, ['convertNullToXsiNil' => true]));
+});
+
 it('can convert an array with empty string and null value to xml', function () {
     $arr = [
         'testString' => '',

tests/__snapshots__/ArrayToXmlTest__it_can_convert_an_array_with_empty_string_and_null_value_to_xml__1.xml

@@ -1,5 +1,5 @@
 <?xml version="1.0"?>
-<root xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance">
+<root>
   <testString/>
-  <testNull xsi:nil="true"/>
+  <testNull/>
 </root>

tests/__snapshots__/ArrayToXmlTest__it_can_convert_an_array_with_empty_string_and_null_value_to_xml_with_option__1.xml

@@ -0,0 +1,5 @@
+<?xml version="1.0"?>
+<root xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance">
+  <testString/>
+  <testNull xsi:nil="true"/>
+</root>