Merge pull request #86 from veewee/allow-empty-docs-on-configurators

Allow empty docs inside configurators like pretty_print

Author: veewee

docs/dom.md

@@ -647,6 +647,18 @@ $document = Document::fromLoader($loader, ...$configurators);
 
 ## Loaders
 
+#### xml_document_loader
+
+Loads an XML document from an external `Dom\XMLDocument`.
+It copies the content of the external document into a new `Dom\XMLDocument` and re-applies e.g. LIBXML flags.
+
+```php
+use VeeWee\Xml\Dom\Document;
+use VeeWee\Xml\Dom\Loader\xml_document_loader;
+
+$doc = Document::fromLoader(xml_document_loader($originalDocument, options: LIBXML_NOCDATA, override_encoding: 'UTF-8'));
+```
+
 #### xml_file_loader
 
 Loads an XML document from a file.

src/Xml/Dom/Configurator/canonicalize.php

@@ -15,13 +15,18 @@
  */
 function canonicalize(): Closure
 {
-    return static fn (XMLDocument $document): XMLDocument
-        => Document::fromLoader(
+    return static function (XMLDocument $document): XMLDocument {
+        if (!$document->documentElement) {
+            return $document;
+        }
+
+        return Document::fromLoader(
             xml_string_loader(
                 non_empty_string()->assert($document->C14N()),
                 LIBXML_NSCLEAN + LIBXML_NOCDATA
             ),
             pretty_print(),
-            normalize()
+            normalize(),
         )->toUnsafeDocument();
+    };
 }

src/Xml/Dom/Configurator/pretty_print.php

@@ -7,23 +7,20 @@
 use Closure;
 use Dom\XMLDocument;
 use VeeWee\Xml\Dom\Document;
-use function VeeWee\Xml\Dom\Loader\xml_string_loader;
+use function VeeWee\Xml\Dom\Loader\xml_document_loader;
 
 /**
  * @return Closure(XMLDocument): XMLDocument
  */
 function pretty_print(): Closure
 {
     return static function (XMLDocument $document): XMLDocument {
-        $trimmed = Document::fromLoader(
-            xml_string_loader(
-                Document::fromUnsafeDocument($document)->toXmlString(),
-                LIBXML_NOBLANKS
-            )
+        $prettyPrinted = Document::fromLoader(
+            xml_document_loader($document, LIBXML_NOBLANKS)
         )->toUnsafeDocument();
 
-        $trimmed->formatOutput = true;
+        $prettyPrinted->formatOutput = true;
 
-        return $trimmed;
+        return $prettyPrinted;
     };
 }

src/Xml/Dom/Configurator/trim_spaces.php

@@ -7,7 +7,7 @@
 use Closure;
 use Dom\XMLDocument;
 use VeeWee\Xml\Dom\Document;
-use function VeeWee\Xml\Dom\Loader\xml_string_loader;
+use function VeeWee\Xml\Dom\Loader\xml_document_loader;
 
 /**
  * @return Closure(XMLDocument): XMLDocument
@@ -16,10 +16,7 @@ function trim_spaces(): Closure
 {
     return static function (XMLDocument $document): XMLDocument {
         $trimmed = Document::fromLoader(
-            xml_string_loader(
-                Document::fromUnsafeDocument($document)->toXmlString(),
-                LIBXML_NOBLANKS
-            )
+            xml_document_loader($document, LIBXML_NOBLANKS)
         )->toUnsafeDocument();
 
         $trimmed->formatOutput = false;

src/Xml/Dom/Loader/xml_document_loader.php

@@ -0,0 +1,35 @@
+<?php
+
+declare(strict_types=1);
+
+namespace VeeWee\Xml\Dom\Loader;
+
+use Closure;
+use Dom\XMLDocument;
+use function Psl\Type\non_empty_string;
+use function VeeWee\Xml\ErrorHandling\disallow_issues;
+
+/**
+ * Loads a copy of current document.
+ *
+ * @param int $options - bitmask of LIBXML_* constants https://www.php.net/manual/en/libxml.constants.php
+ * @return Closure(): XMLDocument
+ */
+function xml_document_loader(
+    XMLDocument $importedDocument,
+    int $options = 0,
+    ?string $override_encoding = null
+): Closure {
+    return static fn () => disallow_issues(static function () use ($importedDocument, $options, $override_encoding): XMLDocument {
+
+        if ($importedDocument->documentElement === null) {
+            return XMLDocument::createEmpty($importedDocument->xmlVersion, $importedDocument->xmlEncoding);
+        }
+
+        return XMLDocument::createFromString(
+            non_empty_string()->assert($importedDocument->saveXml()),
+            $options,
+            $override_encoding
+        );
+    });
+}

src/bootstrap.php

@@ -32,6 +32,7 @@
         'Xml\Dom\Configurator\trim_spaces' => __DIR__.'/Xml/Dom/Configurator/trim_spaces.php',
         'Xml\Dom\Configurator\utf8' => __DIR__.'/Xml/Dom/Configurator/utf8.php',
         'Xml\Dom\Configurator\validator' => __DIR__.'/Xml/Dom/Configurator/validator.php',
+        'Xml\Dom\Loader\xml_document_loader' => __DIR__.'/Xml/Dom/Loader/xml_document_loader.php',
         'Xml\Dom\Loader\xml_file_loader' => __DIR__.'/Xml/Dom/Loader/xml_file_loader.php',
         'Xml\Dom\Loader\xml_node_loader' => __DIR__.'/Xml/Dom/Loader/xml_node_loader.php',
         'Xml\Dom\Loader\xml_string_loader' => __DIR__.'/Xml/Dom/Loader/xml_string_loader.php',

tests/Xml/Dom/Configurator/CanonicalizeTest.php

@@ -23,6 +23,16 @@ public function test_it_can_canonicalize(string $input, string $expected): void
         static::assertSame($expected, $actual);
     }
 
+    public function test_it_can_canonicalize_empty_xml(): void
+    {
+        $configurator = canonicalize();
+
+        $doc = Document::empty()->toUnsafeDocument();
+        $result = $configurator($doc);
+
+        static::assertSame($doc, $result);
+    }
+
     public static function provideXmls()
     {
         yield 'no-action' => [

tests/Xml/Dom/Configurator/PrettyPrintTest.php

@@ -11,7 +11,7 @@
 
 final class PrettyPrintTest extends TestCase
 {
-    public function test_it_can_trim_contents(): void
+    public function test_it_can_pretty_print_contents(): void
     {
         $configurator = pretty_print();
 
@@ -28,4 +28,27 @@ public function test_it_can_trim_contents(): void
         static::assertTrue($result->formatOutput);
         static::assertSame($expected, xml_string()($result->documentElement));
     }
+
+    public function test_it_can_pretty_print_empty_xml(): void
+    {
+        $configurator = pretty_print();
+
+        $doc = Document::empty()->toUnsafeDocument();
+        $result = $configurator($doc);
+
+        $result->append(
+            $hello = $result->createElement('hello')
+        );
+        $hello->append($result->createElement('world'));
+
+        $expected = <<<EOXML
+        <hello>
+          <world/>
+        </hello>
+        EOXML;
+
+        static::assertNotSame($doc, $result);
+        static::assertTrue($result->formatOutput);
+        static::assertSame($expected, xml_string()($result->documentElement));
+    }
 }

tests/Xml/Dom/Configurator/TrimSpacesTest.php

@@ -21,4 +21,25 @@ public function test_it_can_trim_contents(): void
         static::assertFalse($result->formatOutput);
         static::assertSame('<hello><world/></hello>', xml_string()($result->documentElement));
     }
+
+    public function test_it_can_trim_spaces_on_empty_xml(): void
+    {
+        $configurator = trim_spaces();
+
+        $doc = Document::empty()->toUnsafeDocument();
+        $result = $configurator($doc);
+
+        $result->append(
+            $hello = $result->createElement('hello')
+        );
+        $hello->append($result->createElement('world'));
+
+        $expected = <<<EOXML
+        <hello><world/></hello>
+        EOXML;
+
+        static::assertNotSame($doc, $result);
+        static::assertFalse($result->formatOutput);
+        static::assertSame($expected, xml_string()($result->documentElement));
+    }
 }

tests/Xml/Dom/Loader/XmlDocumentLoaderTest.php

@@ -0,0 +1,54 @@
+<?php
+
+declare(strict_types=1);
+
+namespace VeeWee\Tests\Xml\Dom\Loader;
+
+use Dom\XMLDocument;
+use PHPUnit\Framework\TestCase;
+use function VeeWee\Xml\Dom\Loader\xml_document_loader;
+
+final class XmlDocumentLoaderTest extends TestCase
+{
+    public function test_it_can_load_xml_string(): void
+    {
+        $initialDoc = XMLDocument::createFromString('<hello />');
+        $loader = xml_document_loader($initialDoc);
+        $doc = $loader();
+
+        static::assertXmlStringEqualsXmlString($initialDoc->saveXml(), $doc->saveXML());
+    }
+
+    public function test_it_can_load_xml_string_with_different_charset(): void
+    {
+        $initialDoc = XMLDocument::createFromString('<hello>héllo</hello>');
+        $loader = xml_document_loader($initialDoc, override_encoding: 'Windows-1252');
+        $doc = $loader();
+
+        static::assertNotSame($initialDoc, $doc);
+        static::assertSame('héllo', $doc->documentElement->textContent);
+        static::assertSame('Windows-1252', $doc->xmlEncoding);
+    }
+
+    public function test_it_can_load_with_options(): void
+    {
+        $initialDoc = XMLDocument::createFromString('<hello><![CDATA[HELLO]]></hello>');
+        $loader = xml_document_loader($initialDoc, options: LIBXML_NOCDATA);
+        $doc = $loader();
+
+        static::assertNotSame($initialDoc, $doc);
+        static::assertSame('<hello>HELLO</hello>', $doc->saveXML($doc->documentElement));
+    }
+
+    public function test_it_can_load_empty_xml_string(): void
+    {
+        $initialDoc = XMLDocument::createEmpty(version: '1.1', encoding: 'ASCII');
+        $loader = xml_document_loader($initialDoc);
+        $doc = $loader();
+
+        static::assertSame($initialDoc->saveXml(), $doc->saveXML());
+        static::assertSame('ASCII', $doc->xmlEncoding);
+        static::assertSame('1.1', $doc->xmlVersion);
+    }
+
+}