3 files changed, 274 insertions, 0 deletions
diff --git a/library/Icinga/Data/Tree/SimpleTree.php b/library/Icinga/Data/Tree/SimpleTree.php
new file mode 100644
index 0000000..e89f589
--- /dev/null
+++ b/library/Icinga/Data/Tree/SimpleTree.php
@@ -0,0 +1,90 @@
+<?php
+/* Icinga Web 2 | (c) 2015 Icinga Development Team | GPLv2+ */
+
+namespace Icinga\Data\Tree;
+
+use IteratorAggregate;
+use LogicException;
+use Traversable;
+
+/**
+ * A simple tree
+ */
+class SimpleTree implements IteratorAggregate
+{
+    /**
+     * Root node
+     *
+     * @var TreeNode
+     */
+    protected $sentinel;
+
+    /**
+     * Nodes
+     *
+     * @var array
+     */
+    protected $nodes = array();
+
+    /**
+     * Create a new simple tree
+     */
+    public function __construct()
+    {
+        $this->sentinel = new TreeNode();
+    }
+
+    /**
+     * Add a child node
+     *
+     * @param   TreeNode $child
+     * @param   TreeNode $parent
+     *
+     * @return $this
+     */
+    public function addChild(TreeNode $child, TreeNode $parent = null)
+    {
+        if ($parent === null) {
+            $parent = $this->sentinel;
+        } elseif (! isset($this->nodes[$parent->getId()])) {
+            throw new LogicException(sprintf(
+                'Can\'t append child node %s to parent node %s: Parent node does not exist',
+                $child->getId(),
+                $parent->getId()
+            ));
+        }
+        if (isset($this->nodes[$child->getId()])) {
+            throw new LogicException(sprintf(
+                'Can\'t append child node %s to parent node %s: Child node does already exist',
+                $child->getId(),
+                $parent->getId()
+            ));
+        }
+        $this->nodes[$child->getId()] = $child;
+        $parent->appendChild($child);
+        return $this;
+    }
+
+    /**
+     * Get a node by its ID
+     *
+     * @param   mixed   $id
+     *
+     * @return  TreeNode|null
+     */
+    public function getNode($id)
+    {
+        if (! isset($this->nodes[$id])) {
+            return null;
+        }
+        return $this->nodes[$id];
+    }
+
+    /**
+     * @return TreeNodeIterator
+     */
+    public function getIterator(): Traversable
+    {
+        return new TreeNodeIterator($this->sentinel);
+    }
+}
diff --git a/library/Icinga/Data/Tree/TreeNode.php b/library/Icinga/Data/Tree/TreeNode.php
new file mode 100644
index 0000000..66bce79
--- /dev/null
+++ b/library/Icinga/Data/Tree/TreeNode.php
@@ -0,0 +1,109 @@
+<?php
+/* Icinga Web 2 | (c) 2014 Icinga Development Team | GPLv2+ */
+
+namespace Icinga\Data\Tree;
+
+use Icinga\Data\Identifiable;
+
+class TreeNode implements Identifiable
+{
+    /**
+     * The node's ID
+     *
+     * @var mixed
+     */
+    protected $id;
+
+    /**
+     * The node's value
+     *
+     * @var mixed
+     */
+    protected $value;
+
+    /**
+     * The node's children
+     *
+     * @var array
+     */
+    protected $children = array();
+
+    /**
+     * Set the node's ID
+     *
+     * @param   mixed   $id ID of the node
+     *
+     * @return  $this
+     */
+    public function setId($id)
+    {
+        $this->id = $id;
+        return $this;
+    }
+
+    /**
+     * (non-PHPDoc)
+     * @see Identifiable::getId() For the method documentation.
+     */
+    public function getId()
+    {
+        return $this->id;
+    }
+
+    /**
+     * Set the node's value
+     *
+     * @param   mixed   $value
+     *
+     * @return  $this
+     */
+    public function setValue($value)
+    {
+        $this->value = $value;
+        return $this;
+    }
+
+    /**
+     * Get the node's value
+     *
+     * @return mixed
+     */
+    public function getValue()
+    {
+        return $this->value;
+    }
+
+    /**
+     * Append a child node as the last child of this node
+     *
+     * @param   TreeNode    $child  The child to append
+     *
+     * @return  $this
+     */
+    public function appendChild(TreeNode $child)
+    {
+        $this->children[] = $child;
+        return $this;
+    }
+
+
+    /**
+     * Get whether the node has children
+     *
+     * @return bool
+     */
+    public function hasChildren()
+    {
+        return ! empty($this->children);
+    }
+
+    /**
+     * Get the node's children
+     *
+     * @return array
+     */
+    public function getChildren()
+    {
+        return $this->children;
+    }
+}
diff --git a/library/Icinga/Data/Tree/TreeNodeIterator.php b/library/Icinga/Data/Tree/TreeNodeIterator.php
new file mode 100644
index 0000000..1c71787
--- /dev/null
+++ b/library/Icinga/Data/Tree/TreeNodeIterator.php
@@ -0,0 +1,75 @@
+<?php
+/* Icinga Web 2 | (c) 2015 Icinga Development Team | GPLv2+ */
+
+namespace Icinga\Data\Tree;
+
+use ArrayIterator;
+use RecursiveIterator;
+
+/**
+ * Iterator over a tree node's children
+ */
+class TreeNodeIterator implements RecursiveIterator
+{
+    /**
+     * The node's children
+     *
+     * @var ArrayIterator
+     */
+    protected $children;
+
+    /**
+     * Create a new iterator over a tree node's children
+     *
+     * @param TreeNode $node
+     */
+    public function __construct(TreeNode $node)
+    {
+        $this->children = new ArrayIterator($node->getChildren());
+    }
+
+    public function current(): TreeNode
+    {
+        return $this->children->current();
+    }
+
+    public function key(): int
+    {
+        return $this->children->key();
+    }
+
+    public function next(): void
+    {
+        $this->children->next();
+    }
+
+    public function rewind(): void
+    {
+        $this->children->rewind();
+    }
+
+    public function valid(): bool
+    {
+        return $this->children->valid();
+    }
+
+    public function hasChildren(): bool
+    {
+        return $this->current()->hasChildren();
+    }
+
+    public function getChildren(): TreeNodeIterator
+    {
+        return new static($this->current());
+    }
+
+    /**
+     * Get whether the iterator is empty
+     *
+     * @return bool
+     */
+    public function isEmpty()
+    {
+        return ! $this->children->count();
+    }
+}