Rework Engine::process, handle variables in meta block

app/Engine/Engine.php

@@ -52,39 +52,62 @@ class Engine
 	{
 		$file_helper = new File([dirname(realpath($input_file))]);
 
+		$documents = [];
+
+		// First, figure out which files to process and load all files.
 		$files = [basename($input_file)];
-		$processed = [];
 
 		for ($i = 0; $i < sizeof($files); $i++)
 		{
-			// Read the current document
-			$document = $this->unserialize->unserialize(file_get_contents($file_helper->resolve($files[$i])));
-
-			// If we haven't already examined this document's list of included templates,
-			// then read those and add them to the stack.
-			if (!in_array($files[$i], $processed))
+			if (!isset($documents[$files[$i]]))
 			{
-				$additional_files = [];
+				$documents[$files[$i]] = $document = $this->unserialize->unserialize(file_get_contents($file_helper->resolve($files[$i])));
 				try
 				{
-					$additional_files = $document->getMeta('stack');
+					$includes = $document->getMeta('stack');
 				}
 				catch (\Exception $ex)
 				{
 				}
-				// If the document specified any includes, then push those into our list of templates to process _before_
-				// the existing templates, then walk our loop index back one to reprocess the current index (now one of
-				// the inserted files)
-				if (sizeof($additional_files))
+				if (sizeof($includes))
 				{
-					$processed[] = $files[$i];
-					array_splice($files, $i, 0, $additional_files);
+					array_splice($files, $i, 0, $includes);
 					--$i;
-					continue;
 				}
 			}
+		}
 
-			$this->compileDocument($document);
+		// Go through and load all the variables
+		$variables = [];
+		for ($i = 0; $i < sizeof($files); $i++)
+		{
+			$file_variables = [];
+			try
+			{
+				$file_variables = $documents[$files[$i]]->getMeta('variables');
+			}
+			catch (\Exception $ex)
+			{
+			}
+
+			foreach ($file_variables as $k => $v)
+			{
+				$variables[$k] = $v;
+			}
+		}
+
+		foreach ($variables as $k => $v)
+		{
+			if (!$options->hasVariable($k))
+			{
+				$options->setVariable($k, $v);
+			}
+		}
+
+		// Now actually process all the documents
+		for ($i = 0; $i < sizeof($files); $i++)
+		{
+			$this->compileDocument($documents[$files[$i]]);
 		}
 
 		// Set metadata in output