cs Iterator and Registry

Iterator/RowSet.php

@@ -0,0 +1,100 @@
+<?php
+
+namespace DesignPatterns\Iterator;
+
+/**
+ * Class RowSet
+ */
+class RowSet implements \Iterator
+{
+    /**
+     * @var
+     */
+    protected $currentRow;
+
+    /**
+     * @var string
+     */
+    protected $file;
+
+    /**
+     * @var int
+     */
+    protected $lineNumber;
+
+    /**
+     * @param string $file
+     */
+    public function __construct($file)
+    {
+        $this->file = $file;
+    }
+
+    /**
+     * composite pattern: run through all rows and process them
+     *
+     * @return void
+     */
+    public function process()
+    {
+        // this actually calls rewind(), { next(), valid(), key() and current() :}
+        /**
+         * THE key feature of the Iterator Pattern is to provide a *public contract*
+         * to iterate on a collection without knowing how items are handled inside
+         * the collection. It is not just an easy way to use "foreach"
+         *
+         * One cannot see the point of iterator pattern if you iterate on $this.
+         * This example is unclear and mixed with some Composite pattern ideas.
+         */
+        foreach ($this as $line => $row) {
+            $row->process();
+        }
+    }
+
+    /**
+     * {@inheritdoc}
+     */
+    public function rewind()
+    {
+        // seek to first line from $this->file
+    }
+
+    /**
+     * {@inheritdoc}
+     */
+    public function next()
+    {
+        // read the next line from $this->file
+        if (!$eof) {
+            $data = ''; // get the line
+            $this->currentRow = new Row($data);
+        } else {
+            $this->currentRow = null;
+        }
+    }
+
+    /**
+     * {@inheritdoc}
+     */
+    public function current()
+    {
+        return $this->currentRow;
+    }
+
+    /**
+     * {@inheritdoc}
+     */
+    public function valid()
+    {
+        return null !== $this->currentRow;
+    }
+
+    /**
+     * {@inheritdoc}
+     */
+    public function key()
+    {
+        // you would want to increment this in next() or whatsoever
+        return $this->lineNumber;
+    }
+}