4 files changed, 185 insertions, 10 deletions
diff --git a/phpBB/includes/template/compile.php b/phpBB/includes/template/compile.php
index 22da21820e..fcdaf7abda 100644
--- a/phpBB/includes/template/compile.php
+++ b/phpBB/includes/template/compile.php
@@ -35,16 +35,23 @@ class phpbb_template_compile
 	/**
 	* Constructor.
 	*
-	* @param bool @allow_php Whether PHP code will be allowed in templates (inline PHP code, PHP tag and INCLUDEPHP tag)
+	* @param bool $allow_php Whether PHP code will be allowed in templates (inline PHP code, PHP tag and INCLUDEPHP tag)
+	* @param array $style_names Name of style to which the template being compiled belongs and parents in style tree order
 	* @param phpbb_style_resource_locator $locator Resource locator
 	* @param string $phpbb_root_path Path to phpBB root directory
+	* @param phpbb_extension_manager $extension_manager Extension manager to use for finding template fragments in extensions; if null, template events will not be invoked
+	* @param phpbb_user $user Current user
 	*/
-	public function __construct($allow_php, $locator, $phpbb_root_path)
+	public function __construct($allow_php, $style_names, $locator, $phpbb_root_path, $extension_manager = null, $user = null)
 	{
 		$this->filter_params = array(
 			'allow_php'	=> $allow_php,
+			'style_names'	=> $style_names,
 			'locator'	=> $locator,
-			'phpbb_root_path'	=> $phpbb_root_path
+			'phpbb_root_path'	=> $phpbb_root_path,
+			'extension_manager'	=> $extension_manager,
+			'user'          => $user,
+			'template_compile'	=> $this,
 		);
 	}
 
diff --git a/phpBB/includes/template/filter.php b/phpBB/includes/template/filter.php
index 66d28242a3..f73ad28ba1 100644
--- a/phpBB/includes/template/filter.php
+++ b/phpBB/includes/template/filter.php
@@ -88,6 +88,37 @@ class phpbb_template_filter extends php_user_filter
 	private $phpbb_root_path;
 
 	/**
+	* Name of the style that the template being compiled and/or rendered
+	* belongs to, and its parents, in inheritance tree order.
+	*
+	* Used to invoke style-specific template events.
+	*
+	* @var array
+	*/
+	private $style_names;
+
+	/**
+	* Extension manager.
+	*
+	* @var phpbb_extension_manager
+	*/
+	private $extension_manager;
+
+	/**
+	* Current user
+	*
+	* @var phpbb_user
+	*/
+	private $user;
+
+	/**
+	* Template compiler.
+	*
+	* @var phpbb_template_compile
+	*/
+	private $template_compile;
+
+	/**
 	* Stream filter
 	*
 	* Is invoked for evey chunk of the stream, allowing us
@@ -138,8 +169,10 @@ class phpbb_template_filter extends php_user_filter
 	/**
 	* Initializer, called on creation.
 	*
-	* Get the allow_php option, root directory and locator from params,
+	* Get the allow_php option, style_names, root directory and locator from params,
 	* which are passed to stream_filter_append.
+	*
+	* @return boolean Returns true
 	*/
 	public function onCreate()
 	{
@@ -148,6 +181,13 @@ class phpbb_template_filter extends php_user_filter
 		$this->allow_php = $this->params['allow_php'];
 		$this->locator = $this->params['locator'];
 		$this->phpbb_root_path = $this->params['phpbb_root_path'];
+		$this->style_names = $this->params['style_names'];
+		$this->extension_manager = $this->params['extension_manager'];
+		if (isset($this->params['user']))
+		{
+			$this->user = $this->params['user'];
+		}
+		$this->template_compile = $this->params['template_compile'];
 		return true;
 	}
 
@@ -229,7 +269,9 @@ class phpbb_template_filter extends php_user_filter
 	}
 
 	/**
-	* Callback for replacing matched tokens with PHP code
+	* Callback for replacing matched tokens with compiled template code.
+	*
+	* Compiled template code is an HTML stream with embedded PHP.
 	*
 	* @param array $matches Regular expression matches
 	* @return string compiled template code
@@ -317,6 +359,10 @@ class phpbb_template_filter extends php_user_filter
 				return '<!-- ENDPHP -->';
 			break;
 
+			case 'EVENT':
+				return '<?php ' . $this->compile_tag_event($matches[2]) . '?>';
+			break;
+
 			default:
 				return $matches[0];
 			break;
@@ -836,6 +882,97 @@ class phpbb_template_filter extends php_user_filter
 	}
 
 	/**
+	* Compile EVENT tag.
+	*
+	* $tag_args should be a single string identifying the event.
+	* The event name can contain letters, numbers and underscores only.
+	* If an invalid event name is specified, an E_USER_ERROR will be
+	* triggered.
+	*
+	* Event tags are only functional when the template engine has
+	* an instance of the extension manager. Extension manager would
+	* be called upon to find all extensions listening for the specified
+	* event, and to obtain additional template fragments. All such
+	* template fragments will be compiled and included in the generated
+	* compiled template code for the current template being compiled.
+	*
+	* The above means that whenever an extension is enabled or disabled,
+	* template cache should be cleared in order to update the compiled
+	* template code for the active set of template event listeners.
+	*
+	* This also means that extensions cannot return different template
+	* fragments at different times. Once templates are compiled, changing
+	* such template fragments would have no effect.
+	*
+	* @param string $tag_args EVENT tag arguments, as a string - for EVENT this is the event name
+	* @return string compiled template code
+	*/
+	private function compile_tag_event($tag_args)
+	{
+		if (!preg_match('/^\w+$/', $tag_args))
+		{
+			// The event location is improperly formatted,
+			if ($this->user)
+			{
+				trigger_error($this->user->lang('ERR_TEMPLATE_EVENT_LOCATION', $tag_args), E_USER_ERROR);
+			}
+			else
+			{
+				trigger_error(sprintf('The specified template event location <em>[%s]</em> is improperly formatted.', $tag_args), E_USER_ERROR);
+			}
+		}
+		$location = $tag_args;
+
+		if ($this->extension_manager)
+		{
+			$finder = $this->extension_manager->get_finder();
+
+			$files = $finder
+				->extension_prefix($location)
+				->extension_suffix('.html')
+				->extension_directory("/styles/all/template")
+				->get_files();
+
+			foreach ($this->style_names as $style_name)
+			{
+				$more_files = $finder
+					->extension_prefix($location)
+					->extension_suffix('.html')
+					->extension_directory("/styles/" . $style_name . "/template")
+					->get_files();
+				if (!empty($more_files))
+				{
+					$files = array_merge($files, $more_files);
+					break;
+				}
+			}
+
+			$all_compiled = '';
+			foreach ($files as $file)
+			{
+				$compiled = $this->template_compile->compile_file($file);
+
+				if ($compiled === false)
+				{
+					if ($this->user)
+					{
+						trigger_error($this->user->lang('ERR_TEMPLATE_COMPILATION', phpbb_filter_root_path($file)), E_USER_ERROR);
+					}
+					else
+					{
+						trigger_error(sprintf('The file could not be compiled: %s', phpbb_filter_root_path($file)), E_USER_ERROR);
+					}
+				}
+
+				$all_compiled .= $compiled;
+			}
+			// Need spaces inside php tags as php cannot grok
+			// < ?php? > sans the spaces
+			return ' ?' . '>' . $all_compiled . '<?php ';
+		}
+	}
+
+	/**
 	* parse expression
 	* This is from Smarty
 	*/
diff --git a/phpBB/includes/template/locator.php b/phpBB/includes/template/locator.php
index 42db91efb2..f6fd20bcc2 100644
--- a/phpBB/includes/template/locator.php
+++ b/phpBB/includes/template/locator.php
@@ -39,7 +39,7 @@ interface phpbb_template_locator
 	* Sets the template filenames for handles. $filename_array
 	* should be a hash of handle => filename pairs.
 	*
-	* @param array $filname_array Should be a hash of handle => filename pairs.
+	* @param array $filename_array Should be a hash of handle => filename pairs.
 	*/
 	public function set_filenames(array $filename_array);
 
@@ -66,7 +66,7 @@ interface phpbb_template_locator
 	* returns actually exists, it is faster than get_source_file_for_handle.
 	*
 	* Use get_source_file_for_handle to obtain the actual path that is
-	* guaranteed to exist (which might come from the parent style 
+	* guaranteed to exist (which might come from the parent style
 	* directory if primary style has parent styles).
 	*
 	* This function will trigger an error if the handle was never
diff --git a/phpBB/includes/template/template.php b/phpBB/includes/template/template.php
index 5396ddbfad..bbec768613 100644
--- a/phpBB/includes/template/template.php
+++ b/phpBB/includes/template/template.php
@@ -75,14 +75,32 @@ class phpbb_template
 	private $locator;
 
 	/**
+	* Extension manager.
+	*
+	* @var phpbb_extension_manager
+	*/
+	private $extension_manager;
+
+	/**
+	* Name of the style that the template being compiled and/or rendered
+	* belongs to, and its parents, in inheritance tree order.
+	*
+	* Used to invoke style-specific template events.
+	*
+	* @var array
+	*/
+	private $style_names;
+
+	/**
 	* Constructor.
 	*
 	* @param string $phpbb_root_path phpBB root path
 	* @param user $user current user
 	* @param phpbb_template_locator $locator template locator
 	* @param phpbb_template_context $context template context
+	* @param phpbb_extension_manager $extension_manager extension manager, if null then template events will not be invoked
 	*/
-	public function __construct($phpbb_root_path, $php_ext, $config, $user, phpbb_template_locator $locator, phpbb_template_context $context)
+	public function __construct($phpbb_root_path, $php_ext, $config, $user, phpbb_template_locator $locator, phpbb_template_context $context, phpbb_extension_manager $extension_manager = null)
 	{
 		$this->phpbb_root_path = $phpbb_root_path;
 		$this->php_ext = $php_ext;
@@ -90,12 +108,13 @@ class phpbb_template
 		$this->user = $user;
 		$this->locator = $locator;
 		$this->context = $context;
+		$this->extension_manager = $extension_manager;
 	}
 
 	/**
 	* Sets the template filenames for handles.
 	*
-	* @param array $filname_array Should be a hash of handle => filename pairs.
+	* @param array $filename_array Should be a hash of handle => filename pairs.
 	*/
 	public function set_filenames(array $filename_array)
 	{
@@ -105,6 +124,18 @@ class phpbb_template
 	}
 
 	/**
+	* Sets the style names corresponding to style hierarchy being compiled
+	* and/or rendered.
+	*
+	* @param array $style_names List of style names in inheritance tree order
+	* @return null
+	*/
+	public function set_style_names(array $style_names)
+	{
+		$this->style_names = $style_names;
+	}
+
+	/**
 	* Clears all variables and blocks assigned to this template.
 	*/
 	public function destroy()
@@ -282,7 +313,7 @@ class phpbb_template
 			return new phpbb_template_renderer_include($output_file, $this);
 		}
 
-		$compile = new phpbb_template_compile($this->config['tpl_allow_php'], $this->locator, $this->phpbb_root_path);
+		$compile = new phpbb_template_compile($this->config['tpl_allow_php'], $this->style_names, $this->locator, $this->phpbb_root_path, $this->extension_manager, $this->user);
 
 		if ($compile->compile_file_to_file($source_file, $output_file) !== false)
 		{