Add support for parsing XiK

src/Xik.php

@@ -0,0 +1,142 @@
+<?php
+
+declare(strict_types=1);
+
+namespace Kdl\Kdl;
+
+final class Xik
+{
+    private function __construct()
+    {
+    }
+
+    /**
+     * Parse a KDL string that uses the XML-in-KDL mapping, and produce a DOM document.
+     *
+     * Note: This conversion does not preserve comments or whitespace.
+     */
+    public static function parseString(string $kdl): \DOMDocument
+    {
+        return self::parse(Kdl::parse($kdl));
+    }
+
+    /**
+     * Parse a KDL document that uses the XML-in-KDL mapping, and produce a DOM document.
+     *
+     * Note: This conversion does not preserve comments or whitespace.
+     */
+    public static function parse(Document $in): \DOMDocument
+    {
+        // Remove doctype
+        $nodes = $in->getNodes();
+        if (count($nodes) > 0 && $nodes[0]->getName() === '!doctype') {
+            array_shift($nodes);
+        }
+
+        // Parse XML declaration
+        $xmlDecl = [];
+        if (count($nodes) > 0 && $nodes[0]->getName() === '?xml') {
+            $xmlDecl = array_shift($nodes)->getProperties();
+        }
+
+        // Create the XML DOM document
+        $doc = new \DOMDocument(
+            $xmlDecl['version'] ?? '1.0',
+            $xmlDecl['encoding'] ?? ''
+        );
+
+        // Parse remaining document nodes
+        $namespaces = ['' => null];
+        foreach ($nodes as $node) {
+            self::parseNode($node, $doc, $doc, $namespaces);
+        }
+
+        return $doc;
+    }
+
+    /**
+     * Parse a KDL node and create a DOM node.
+     *
+     * @param array<string, string> $namespaces
+     */
+    private static function parseNode(
+        NodeInterface $in,
+        \DOMParentNode $parent,
+        \DOMDocument $doc,
+        array $namespaces,
+    ): void {
+        $name = $in->getName();
+
+        // Skip any processing instructions
+        if (str_starts_with($name, '?') || str_starts_with($name, '!')) {
+            return;
+        }
+
+        // Parse any new namespace declarations at this level.
+        self::parseNamespaceDeclarations($in, $namespaces);
+
+        // Create the node.
+        [$ns, $name] = self::parseName($name, $namespaces);
+        $out = $doc->createElementNS($ns, $name);
+
+        // Add values as a single text node.
+        $out->appendChild($doc->createTextNode(implode(' ', $in->getValues())));
+
+        // Add attributes.
+        foreach ($in->getProperties() as $name => $value) {
+            // Namespace declarations were already handled by `parseNamespaceDeclarations`
+            if ($name === 'xmlns' || str_starts_with($name, 'xmlns:')) {
+                continue;
+            }
+
+            [$ns, $name] = self::parseName($name, $namespaces);
+            $out->setAttributeNS($ns, $name, (string) $value);
+        }
+
+        // Add children.
+        foreach ($in->getChildren() as $node) {
+            self::parseNode($node, $out, $doc, $namespaces);
+        }
+
+        // Attach to parent.
+        $parent->append($out);
+    }
+
+    /**
+     * Parse XML namespace declarations from a KDL node.
+     *
+     * @param array<string, ?string> $namespaces
+     */
+    private static function parseNamespaceDeclarations(NodeInterface $node, array &$namespaces): void
+    {
+        foreach ($node->getProperties() as $prop => $value) {
+            if ($prop === 'xmlns') {
+                $namespaces[''] = $value;
+            } elseif (str_starts_with($prop, 'xmlns:')) {
+                $namespaces[substr($prop, 6)] = $value;
+            }
+        }
+    }
+
+    /**
+     * Parse an XML element or attribute name into namespace and name.
+     *
+     * @param array<string, ?string> $ns
+     * @return array{?string, string}
+     */
+    private static function parseName(string $name, array &$namespaces): array
+    {
+        $ns = '';
+        $sepIdx = strpos($name, ':');
+        if ($sepIdx !== false) {
+            $ns = substr($name, 0, $sepIdx);
+            $name = substr($name, $sepIdx + 1);
+        }
+        if (!array_key_exists($ns, $namespaces)) {
+            throw new \Exception('Invalid namespace in element name: ' . $ns);
+        }
+        $ns = $namespaces[$ns];
+
+        return [$ns, $name];
+    }
+}

tests/XikTest.php

@@ -0,0 +1,23 @@
+<?php
+
+declare(strict_types=1);
+
+namespace Kdl\Kdl\Tests;
+
+class XikTest extends \PHPUnit\Framework\TestCase
+{
+    public function testXik(): void
+    {
+        $kdl = file_get_contents(__DIR__ . '/kdl/xik.kdl');
+        $xml = file_get_contents(__DIR__ . '/kdl/xik-output.xml');
+
+        $doc = \Kdl\Kdl\Xik::parseString($kdl);
+
+        $formatted = new \DOMDocument();
+        $formatted->preserveWhiteSpace = false;
+        $formatted->formatOutput = true;
+        $formatted->loadXML($doc->saveXML());
+
+        self::assertSame($xml, $formatted->saveXML());
+    }
+}

tests/kdl/xik-output.xml

@@ -0,0 +1,144 @@
+<?xml version="1.0"?>
+<catalog>
+  <book id="bk101">
+    <author>Gambardella, Matthew</author>
+    <title>XML Developer's Guide</title>
+    <genre>Computer</genre>
+    <price>44.95</price>
+    <publish_date>2000-10-01</publish_date>
+    <description>
+      An in-depth look at creating applications
+      with XML.
+    </description>
+  </book>
+  <book id="bk102">
+    <author>Ralls, Kim</author>
+    <title>Midnight Rain</title>
+    <genre>Fantasy</genre>
+    <price>5.95</price>
+    <publish_date>2000-12-16</publish_date>
+    <description>
+      A former architect battles corporate zombies,
+      an evil sorceress, and her own childhood to become queen
+      of the world.
+    </description>
+  </book>
+  <book id="bk103">
+    <author>Corets, Eva</author>
+    <title>Maeve Ascendant</title>
+    <genre>Fantasy</genre>
+    <price>5.95</price>
+    <publish_date>2000-11-17</publish_date>
+    <description>
+      After the collapse of a nanotechnology
+      society in England, the young survivors lay the
+      foundation for a new society.
+    </description>
+  </book>
+  <book id="bk104">
+    <author>Corets, Eva</author>
+    <title>Oberon's Legacy</title>
+    <genre>Fantasy</genre>
+    <price>5.95</price>
+    <publish_date>2001-03-10</publish_date>
+    <description>
+      In post-apocalypse England, the mysterious
+      agent known only as Oberon helps to create a new life
+      for the inhabitants of London. Sequel to Maeve
+      Ascendant.
+    </description>
+  </book>
+  <book id="bk105">
+    <author>Corets, Eva</author>
+    <title>The Sundered Grail</title>
+    <genre>Fantasy</genre>
+    <price>5.95</price>
+    <publish_date>2001-09-10</publish_date>
+    <description>
+      The two daughters of Maeve, half-sisters,
+      battle one another for control of England. Sequel to
+      Oberon's Legacy.
+    </description>
+  </book>
+  <book id="bk106">
+    <author>Randall, Cynthia</author>
+    <title>Lover Birds</title>
+    <genre>Romance</genre>
+    <price>4.95</price>
+    <publish_date>2000-09-02</publish_date>
+    <description>
+      When Carla meets Paul at an ornithology
+      conference, tempers fly as feathers get ruffled.
+    </description>
+  </book>
+  <book id="bk107">
+    <author>Thurman, Paula</author>
+    <title>Splish Splash</title>
+    <genre>Romance</genre>
+    <price>4.95</price>
+    <publish_date>2000-11-02</publish_date>
+    <description>
+      A deep sea diver finds true love twenty
+      thousand leagues beneath the sea.
+    </description>
+  </book>
+  <book id="bk108">
+    <author>Knorr, Stefan</author>
+    <title>Creepy Crawlies</title>
+    <genre>Horror</genre>
+    <price>4.95</price>
+    <publish_date>2000-12-06</publish_date>
+    <description>
+      An anthology of horror stories about roaches,
+      centipedes, scorpions  and other insects.
+    </description>
+  </book>
+  <book id="bk109">
+    <author>Kress, Peter</author>
+    <title>Paradox Lost</title>
+    <genre>Science Fiction</genre>
+    <price>6.95</price>
+    <publish_date>2000-11-02</publish_date>
+    <description>
+      After an inadvertant trip through a Heisenberg
+      Uncertainty Device, James Salway discovers the problems
+      of being quantum.
+    </description>
+  </book>
+  <book id="bk110">
+    <author>O'Brien, Tim</author>
+    <title>Microsoft .NET: The Programming Bible</title>
+    <genre>Computer</genre>
+    <price>36.95</price>
+    <publish_date>2000-12-09</publish_date>
+    <description>
+      Microsoft's .NET initiative is explored in
+      detail in this deep programmer's reference.
+    </description>
+  </book>
+  <book id="bk111">
+    <author>O'Brien, Tim</author>
+    <title>MSXML3: A Comprehensive Guide</title>
+    <genre>Computer</genre>
+    <price>36.95</price>
+    <publish_date>2000-12-01</publish_date>
+    <description>
+      The Microsoft MSXML3 parser is covered in
+      detail, with attention to XML DOM interfaces, XSLT processing,
+      SAX and more.
+    </description>
+  </book>
+  <book id="bk112">
+    <author>Galos, Mike</author>
+    <title>Visual Studio 7: A Comprehensive Guide</title>
+    <genre>Computer</genre>
+    <price>49.95</price>
+    <publish_date>2001-04-16</publish_date>
+    <description>
+      Microsoft Visual Studio 7 is explored in depth,
+      looking at how Visual Basic, Visual C++, C#, and ASP+ are
+      integrated into a comprehensive development
+      environment.
+    </description>
+  </book>
+</catalog>