1 files changed, 168 insertions, 0 deletions
diff --git a/Mustache/HelperCollection.php b/Mustache/HelperCollection.php
new file mode 100644
index 0000000..92bcde4
--- /dev/null
+++ b/Mustache/HelperCollection.php
@@ -0,0 +1,168 @@
+<?php
+
+/*
+ * This file is part of Mustache.php.
+ *
+ * (c) 2012 Justin Hileman
+ *
+ * For the full copyright and license information, please view the LICENSE
+ * file that was distributed with this source code.
+ */
+
+/**
+ * A collection of helpers for a Mustache instance.
+ */
+class Mustache_HelperCollection
+{
+    private $helpers = array();
+
+    /**
+     * Helper Collection constructor.
+     *
+     * Optionally accepts an array (or Traversable) of `$name => $helper` pairs.
+     *
+     * @throws InvalidArgumentException if the $helpers argument isn't an array or Traversable
+     *
+     * @param array|Traversable $helpers (default: null)
+     */
+    public function __construct($helpers = null)
+    {
+        if ($helpers !== null) {
+            if (!is_array($helpers) && !$helpers instanceof Traversable) {
+                throw new InvalidArgumentException('HelperCollection constructor expects an array of helpers');
+            }
+
+            foreach ($helpers as $name => $helper) {
+                $this->add($name, $helper);
+            }
+        }
+    }
+
+    /**
+     * Magic mutator.
+     *
+     * @see Mustache_HelperCollection::add
+     *
+     * @param string $name
+     * @param mixed  $helper
+     */
+    public function __set($name, $helper)
+    {
+        $this->add($name, $helper);
+    }
+
+    /**
+     * Add a helper to this collection.
+     *
+     * @param string $name
+     * @param mixed  $helper
+     */
+    public function add($name, $helper)
+    {
+        $this->helpers[$name] = $helper;
+    }
+
+    /**
+     * Magic accessor.
+     *
+     * @see Mustache_HelperCollection::get
+     *
+     * @param string $name
+     *
+     * @return mixed Helper
+     */
+    public function __get($name)
+    {
+        return $this->get($name);
+    }
+
+    /**
+     * Get a helper by name.
+     *
+     * @param string $name
+     *
+     * @return mixed Helper
+     */
+    public function get($name)
+    {
+        if (!$this->has($name)) {
+            throw new InvalidArgumentException('Unknown helper: '.$name);
+        }
+
+        return $this->helpers[$name];
+    }
+
+    /**
+     * Magic isset().
+     *
+     * @see Mustache_HelperCollection::has
+     *
+     * @param string $name
+     *
+     * @return boolean True if helper is present
+     */
+    public function __isset($name)
+    {
+        return $this->has($name);
+    }
+
+    /**
+     * Check whether a given helper is present in the collection.
+     *
+     * @param string $name
+     *
+     * @return boolean True if helper is present
+     */
+    public function has($name)
+    {
+        return array_key_exists($name, $this->helpers);
+    }
+
+    /**
+     * Magic unset().
+     *
+     * @see Mustache_HelperCollection::remove
+     *
+     * @param string $name
+     */
+    public function __unset($name)
+    {
+        $this->remove($name);
+    }
+
+    /**
+     * Check whether a given helper is present in the collection.
+     *
+     * @throws InvalidArgumentException if the requested helper is not present.
+     *
+     * @param string $name
+     */
+    public function remove($name)
+    {
+        if (!$this->has($name)) {
+            throw new InvalidArgumentException('Unknown helper: '.$name);
+        }
+
+        unset($this->helpers[$name]);
+    }
+
+    /**
+     * Clear the helper collection.
+     *
+     * Removes all helpers from this collection
+     */
+    public function clear()
+    {
+        $this->helpers = array();
+    }
+
+    /**
+     * Check whether the helper collection is empty.
+     *
+     * @return boolean True if the collection is empty
+     */
+    public function isEmpty()
+    {
+        return empty($this->helpers);
+    }
+}