Merge pull request #1 from mat-b-/mat-b--patch-1

New set_current_variation () function.

It's now possible to redirect users to specific experiment (e.g. from newsletter, or another page) using string queries, like www.example.com?experiment=control

if (isset($_GET['experiment'])) {
$phpab->set_current_variation($_GET['experiment']);
}

phpab.php

@@ -150,6 +150,30 @@ public function set_tag ($t)
 		$this->tag = $t;
 	}
 
+	public function set_current_variation ($new)
+	{
+		if($this->current_variation != '!unset' && $this->current_variation_key != -1)
+		{
+			return FALSE;
+		}
+
+		array_unshift($this->variations, array('name' => 'control', 'value' => ''));
+
+		$this->current_variation_key = 0;
+		foreach($this->variations as $n => $v)
+		{
+			if($v['name'] == $new)
+			{
+				$this->current_variation = $new;
+				return TRUE;
+			}
+			$this->current_variation_key++;
+		}
+
+		unset($this->current_variation_key);
+		return FALSE;
+	}
+
 	public function add_variation ($n, $v = '')
 	{
 		$n = trim(strtolower($n));