+<?php
+/**
+ * Handles compiling Mustache templates into PHP rendering functions
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License along
+ * with this program; if not, write to the Free Software Foundation, Inc.,
+ * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
+ * http://www.gnu.org/copyleft/gpl.html
+ *
+ * @file
+ */
+class TemplateParser {
+ /**
+ * @var string The path to the Mustache templates
+ */
+ protected $templateDir;
+
+ /**
+ * @var callable[] Array of cached rendering functions
+ */
+ protected $renderers;
+
+ /**
+ * @var bool Always compile template files
+ */
+ protected $forceRecompile = false;
+
+ /**
+ * @param string $templateDir
+ * @param boolean $forceRecompile
+ */
+ public function __construct( $templateDir = null, $forceRecompile = false ) {
+ $this->templateDir = $templateDir ? $templateDir : __DIR__.'/templates';
+ $this->forceRecompile = $forceRecompile;
+ }
+
+ /**
+ * Constructs the location of the the source Mustache template
+ * @param string $templateName The name of the template
+ * @return string
+ * @throws Exception Disallows upwards directory traversal via $templateName
+ */
+ public function getTemplateFilename( $templateName ) {
+ // Prevent upwards directory traversal using same methods as Title::secureAndSplit
+ if (
+ strpos( $templateName, '.' ) !== false &&
+ (
+ $templateName === '.' || $templateName === '..' ||
+ strpos( $templateName, './' ) === 0 ||
+ strpos( $templateName, '../' ) === 0 ||
+ strpos( $templateName, '/./' ) !== false ||
+ strpos( $templateName, '/../' ) !== false ||
+ substr( $templateName, -2 ) === '/.' ||
+ substr( $templateName, -3 ) === '/..'
+ )
+ ) {
+ throw new Exception( "Malformed \$templateName: $templateName" );
+ }
+
+ return "{$this->templateDir}/{$templateName}.mustache";
+ }
+
+ /**
+ * Returns a given template function if found, otherwise throws an exception.
+ * @param string $templateName The name of the template (without file suffix)
+ * @return Function
+ * @throws Exception
+ */
+ public function getTemplate( $templateName ) {
+ global $wgSecretKey;
+
+ // If a renderer has already been defined for this template, reuse it
+ if ( isset( $this->renderers[$templateName] ) ) {
+ return $this->renderers[$templateName];
+ }
+
+ $filename = $this->getTemplateFilename( $templateName );
+
+ if ( !file_exists( $filename ) ) {
+ throw new Exception( "Could not locate template: {$filename}" );
+ }
+
+ // Read the template file
+ $fileContents = file_get_contents( $filename );
+
+ // Generate a quick hash for cache invalidation
+ $fastHash = md5( $fileContents );
+
+ // See if the compiled PHP code is stored in cache.
+ // CACHE_ACCEL throws an exception if no suitable object cache is present, so fall
+ // back to CACHE_ANYTHING.
+ try {
+ $cache = wfGetCache( CACHE_ACCEL );
+ } catch ( Exception $e ) {
+ $cache = wfGetCache( CACHE_ANYTHING );
+ }
+ $key = wfMemcKey( 'template', $templateName, $fastHash );
+ $code = $this->forceRecompile ? null : $cache->get( $key );
+
+ if ( !$code ) {
+ // Compile the template into PHP code
+ $code = self::compile( $fileContents );
+
+ if ( !$code ) {
+ throw new Exception( "Could not compile template: {$filename}" );
+ }
+
+ // Strip the "<?php" added by lightncandy so that it can be eval()ed
+ if ( substr( $code, 0, 5 ) === '<?php' ) {
+ $code = substr( $code, 5 );
+ }
+
+ $renderer = eval( $code );
+
+ // Prefix the code with a keyed hash (64 hex chars) as an integrity check
+ $code = hash_hmac( 'sha256', $code, $wgSecretKey ) . $code;
+
+ // Cache the compiled PHP code
+ $cache->set( $key, $code );
+ } else {
+ // Verify the integrity of the cached PHP code
+ $keyedHash = substr( $code, 0, 64 );
+ $code = substr( $code, 64 );
+ if ( $keyedHash === hash_hmac( 'sha256', $code, $wgSecretKey ) ) {
+ $renderer = eval( $code );
+ } else {
+ throw new Exception( "Template failed integrity check: {$filename}" );
+ }
+ }
+
+ return $this->renderers[$templateName] = $renderer;
+ }
+
+ /**
+ * Compile the Mustache code into PHP code using LightnCandy
+ * @param string $code Mustache code
+ * @return string PHP code
+ * @throws Exception
+ */
+ public static function compile( $code ) {
+ if ( !class_exists( 'LightnCandy' ) ) {
+ throw new Exception( 'LightnCandy class not defined' );
+ }
+ return LightnCandy::compile(
+ $code,
+ array(
+ // Do not add more flags here without discussion.
+ // If you do add more flags, be sure to update unit tests as well.
+ 'flags' => LightnCandy::FLAG_ERROR_EXCEPTION
+ )
+ );
+ }
+
+ /**
+ * Returns HTML for a given template by calling the template function with the given args
+ * @param string $templateName The name of the template
+ * @param mixed $args
+ * @param array $scopes
+ * @return string
+ */
+ public function processTemplate( $templateName, $args, array $scopes = array() ) {
+ $template = $this->getTemplate( $templateName );
+ return call_user_func( $template, $args, $scopes );
+ }
+}