Nested child element parsing

examples/child-nested-read.php

@@ -0,0 +1,19 @@
+<?php
+
+require('xmlreader-iterators.php'); // require XMLReaderIterator library
+
+$xmlFile = 'data/products.xml';
+
+/** @var \Traversable<int,\XMLReaderNode> $list */
+$iterator = new XMLElementIterator(XMLReader::open($xmlFile));
+$list     = new XMLElementXpathFilter($iterator, '//product');
+
+foreach ($list as $item) {
+    printf('Found product "%s"' . \PHP_EOL, $item->getAttribute('sku'));
+
+    foreach ($item->getChildElements('attributes') as $attributeList) {
+        foreach ($attributeList->getChildElements() as $attribute) {
+            printf('  - %s: %s' . \PHP_EOL, $attribute->name, (string)$attribute);
+        }
+    }
+}

examples/data/products.xml

@@ -0,0 +1,52 @@
+<?xml version="1.0" encoding="utf-8"?>
+<catalog>
+    <product sku="empty_product"/>
+    <product sku="empty_attributes">
+        <attributes/>
+    </product>
+    <product sku="no_attributes">
+    </product>
+    <product sku="foo">
+        <attributes>
+            <name>Test product</name>
+        </attributes>
+        <variants>
+            <product sku="foo_blue">
+                <attributes>
+                    <name>Test product in blue</name>
+                    <price>15.00</price>
+                </attributes>
+            </product>
+            <product sku="foo_red">
+                <attributes>
+                    <name>Test product in red</name>
+                    <price>12.00</price>
+                </attributes>
+            </product>
+        </variants>
+    </product>
+    <product sku="bar">
+        <attributes>
+            <name>Simple test product</name>
+            <price>10.99</price>
+        </attributes>
+    </product>
+    <product sku="foobar">
+        <attributes>
+            <name>Another product</name>
+            <price>99.99</price>
+        </attributes>
+        <variants>
+            <product sku="foobar_l">
+                <attributes>
+                    <size>L</size>
+                </attributes>
+            </product>
+            <product sku="foobar_m">
+                <attributes>
+                    <size>M</size>
+                </attributes>
+            </product>
+        </variants>
+    </product>
+</catalog>

src/XMLChildElementIterator.php

@@ -53,6 +53,11 @@ class XMLChildElementIterator extends XMLElementIterator
      */
     private $name;
 
+    /**
+     * @var int
+     */
+    private $innerDepth;
+
     /**
      * @inheritdoc
      *
@@ -81,6 +86,11 @@ public function rewind()
             !$this->moveToNextByNodeType(XMLReader::ELEMENT);
         }
 
+        // handles e.g. <parent/> -> no children available
+        if ($this->reader->isEmptyElement) {
+            return;
+        }
+
         if ($this->stopDepth === null) {
             $this->stopDepth = $this->reader->depth;
         }
@@ -89,6 +99,7 @@ public function rewind()
         $result = $this->nextChildElementByName($this->name);
 
         $this->index = $result ? 0 : null;
+        $this->innerDepth = 1;
         $this->didRewind = true;
     }
 
@@ -160,15 +171,15 @@ private function nextChildElementByName($name = null)
             }
         }
 
-        return (bool)$next;
+        return $next;
     }
 
     /**
      * @return bool
      */
     private function nextElement()
     {
-        while ($this->reader->read()) {
+        while ($this->readNext()) {
             if (XMLReader::ELEMENT !== $this->reader->nodeType) {
                 continue;
             }
@@ -177,4 +188,28 @@ private function nextElement()
         }
         return false;
     }
+
+    /**
+     * Wrap reading to track opening and closing tags to prevent reading not-children nodes
+     *
+     * @return bool
+     */
+    protected function readNext()
+    {
+        // update inner depth
+        if ($this->reader->nodeType === XMLReader::ELEMENT && !$this->reader->isEmptyElement) {
+            $this->innerDepth++;
+        } elseif ($this->reader->nodeType === XMLReader::END_ELEMENT) {
+            $this->innerDepth--;
+
+            // all children read? Abort to prevent reading next node
+            if ($this->innerDepth === 0) {
+                // set pointer behind closing-tag
+                parent::readNext();
+                return false;
+            }
+        }
+
+        return parent::readNext();
+    }
 }

src/XMLReaderIterator.php

@@ -167,11 +167,17 @@ public function next()
         if ($this->skipNextRead) {
             $this->skipNextRead = false;
             $this->lastRead = $this->reader->nodeType !== XMLReader::NONE;
-        } elseif ($this->lastRead = $this->reader->read() and $this->reader->nodeType === XMLReader::ELEMENT) {
+        } elseif ($this->lastRead = $this->readNext() and $this->reader->nodeType === XMLReader::ELEMENT) {
             $this->touchElementStack();
         }
     }
 
+    #[\ReturnTypeWillChange]
+    protected function readNext()
+    {
+        return $this->reader->read();
+    }
+
     /**
      * @return string
      * @since 0.0.19

tests/functional/examples/Expectations/child-nested-read_php.out

@@ -0,0 +1,21 @@
+Found product "empty_product"
+Found product "empty_attributes"
+Found product "no_attributes"
+Found product "foo"
+  - name: Test product
+Found product "foo_blue"
+  - name: Test product in blue
+  - price: 15.00
+Found product "foo_red"
+  - name: Test product in red
+  - price: 12.00
+Found product "bar"
+  - name: Simple test product
+  - price: 10.99
+Found product "foobar"
+  - name: Another product
+  - price: 99.99
+Found product "foobar_l"
+  - size: L
+Found product "foobar_m"
+  - size: M

tests/unit/XMLChildElementIteratorTest.php

@@ -91,7 +91,6 @@ public function testIteration()
             $this->assertEquals($expected[$index], $reader->name);
         }
         $this->assertEquals(count($expected), $count);
-
     }
 
     /**
@@ -142,4 +141,26 @@ public function testDescendantChildren()
         $array = iterator_to_array($children, false);
         $this->assertSame(array(), $array, 'all children have been consumed by foreach');
     }
+
+    /**
+     * Test child-iterator without calling 'skipNextRead' method
+     */
+    public function testIterationOnChildrenStopBeforeReadingNextElement()
+    {
+        $reader = XMLReader::open(__DIR__ . '/../../examples/data/sample-rss-091.xml');
+        $this->assertTrue(!!$reader, 'fixture document can be opened successfully');
+        $items = new XMLElementIterator($reader, 'item');
+        foreach ($items as $idx => $item) {
+            $children = $items->getChildElements();
+            $children->rewind();
+            foreach (array('title', 'link', 'description') as $tagName) {
+                $this->assertTrue($children->valid());
+                $this->assertSame($tagName, $children->name);
+                $children->next();
+            }
+            $this->assertFalse($children->valid());
+        }
+        $this->assertSame(6, $idx, 'sample-rss-091.xml element has 7 item elements');
+        $this->assertEmpty(\iterator_to_array($items), 'all children have been consumed by foreach');
+    }
 }