Add more advanced xml writer.

src/AdvancedXmlWriter.php

@@ -0,0 +1,158 @@
+<?php
+
+namespace Port\Xml;
+
+use Port\Writer;
+use Port\Writer\FlushableWriter;
+
+/**
+ * This writer allows you to write more complex XML from arrays than the default XmlWriter.
+ *
+ * The main differences are that nested arrays can be proceed and XML attributes are supported. 
+ * If the key of an array value starts with '@' the value will be used as a XML attribute.
+ */
+class AdvancedXmlWriter implements Writer, FlushableWriter
+{
+    /**
+     * @var \XmlWriter
+     */
+    protected $xmlWriter;
+
+    /**
+     * @var string
+     */
+    protected $file;
+
+    /**
+     * @var string
+     */
+    protected $rootElement;
+
+    /**
+     * @var array<string, string>
+     */
+    protected $rootElementAttributes;
+
+    /**
+     * @var string
+     */
+    protected $itemElement;
+
+    /**
+     * @var string
+     */
+    protected $version;
+
+    /**
+     * @var string|null
+     */
+    protected $encoding;
+
+    /**
+     * @param string $file
+     */
+    public function __construct(
+        \XmlWriter $xmlWriter,
+        $file,
+        $rootElement = 'items',
+        $rootElementAttributes = [],
+        $itemElement = 'item',
+        $version = '1.0',
+        $encoding = null
+    ) {
+        $this->xmlWriter = $xmlWriter;
+        $this->file = $file;
+        $this->rootElement = $rootElement;
+        $this->rootElementAttributes = $rootElementAttributes;
+        $this->itemElement = $itemElement;
+        $this->version = $version;
+        $this->encoding = $encoding;
+    }
+
+    /**
+     * {@inheritdoc}
+     */
+    public function prepare()
+    {
+        $this->xmlWriter->openUri($this->file);
+        $this->xmlWriter->startDocument($this->version, $this->encoding);
+        $this->xmlWriter->startElement($this->rootElement);
+
+        foreach($this->rootElementAttributes as $key => $value) {
+            $this->xmlWriter->writeAttribute($key, $value);
+        }
+    }
+
+    /**
+     * {@inheritdoc}
+     */
+    public function writeItem(array $item)
+    {
+        $this->writeXmlItem($item, $this->itemElement);
+    }
+
+    /**
+     * Handle XML write with attributes support.
+     *
+     * @param array $item
+     * @param $elementName
+     */
+    protected function writeXmlItem(array $item, $elementName)
+    {
+        $this->xmlWriter->startElement($elementName);
+
+        $this->writeAttributes($item);
+
+        foreach ($item as $key => $value) {
+            if (substr($key, 0, 1) === '@') {
+                continue;
+            }
+
+            if (is_array($value)) {
+                $this->writeXmlItem($value, $key);
+            } else {
+                $this->xmlWriter->writeElement($key, $value);
+            }
+        }
+
+        $this->xmlWriter->endElement();
+    }
+
+    /**
+     * Write attributes of item.
+     *
+     * @param array $item
+     */
+    protected function writeAttributes(array $item)
+    {
+        foreach ($item as $key => $value) {
+            if (substr($key, 0, 1) !== '@') {
+                continue;
+            }
+
+            $this->xmlWriter->writeAttribute(
+                substr($key, 1),
+                $value
+            );
+        }
+    }
+
+    /**
+     * {@inheritdoc}
+     */
+    public function finish()
+    {
+        $this->xmlWriter->endElement();
+        $this->xmlWriter->endDocument();
+        $this->flush();
+    }
+
+    /**
+     * {@inheritdoc}
+     */
+    public function flush()
+    {
+        $this->xmlWriter->flush();
+    }
+
+}