2 use MediaWiki\MediaWikiServices
;
5 * Handles compiling Mustache templates into PHP rendering functions
7 * This program is free software; you can redistribute it and/or modify
8 * it under the terms of the GNU General Public License as published by
9 * the Free Software Foundation; either version 2 of the License, or
10 * (at your option) any later version.
12 * This program is distributed in the hope that it will be useful,
13 * but WITHOUT ANY WARRANTY; without even the implied warranty of
14 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
15 * GNU General Public License for more details.
17 * You should have received a copy of the GNU General Public License along
18 * with this program; if not, write to the Free Software Foundation, Inc.,
19 * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
20 * http://www.gnu.org/copyleft/gpl.html
25 class TemplateParser
{
27 * @var string The path to the Mustache templates
29 protected $templateDir;
32 * @var callable[] Array of cached rendering functions
37 * @var bool Always compile template files
39 protected $forceRecompile = false;
42 * @param string $templateDir
43 * @param bool $forceRecompile
45 public function __construct( $templateDir = null, $forceRecompile = false ) {
46 $this->templateDir
= $templateDir ?
: __DIR__
. '/templates';
47 $this->forceRecompile
= $forceRecompile;
51 * Constructs the location of the the source Mustache template
52 * @param string $templateName The name of the template
54 * @throws UnexpectedValueException If $templateName attempts upwards directory traversal
56 protected function getTemplateFilename( $templateName ) {
57 // Prevent path traversal. Based on Language::isValidCode().
58 // This is for paranoia. The $templateName should never come from
61 strcspn( $templateName, ":/\\\000&<>'\"%" ) !== strlen( $templateName )
63 throw new UnexpectedValueException( "Malformed \$templateName: $templateName" );
66 return "{$this->templateDir}/{$templateName}.mustache";
70 * Returns a given template function if found, otherwise throws an exception.
71 * @param string $templateName The name of the template (without file suffix)
73 * @throws RuntimeException
75 protected function getTemplate( $templateName ) {
76 // If a renderer has already been defined for this template, reuse it
77 if ( isset( $this->renderers
[$templateName] ) &&
78 is_callable( $this->renderers
[$templateName] )
80 return $this->renderers
[$templateName];
83 $filename = $this->getTemplateFilename( $templateName );
85 if ( !file_exists( $filename ) ) {
86 throw new RuntimeException( "Could not locate template: {$filename}" );
89 // Read the template file
90 $fileContents = file_get_contents( $filename );
92 // Generate a quick hash for cache invalidation
93 $fastHash = md5( $fileContents );
95 // Fetch a secret key for building a keyed hash of the PHP code
96 $config = MediaWikiServices
::getInstance()->getMainConfig();
97 $secretKey = $config->get( 'SecretKey' );
100 // See if the compiled PHP code is stored in cache.
101 $cache = ObjectCache
::getLocalServerInstance( CACHE_ANYTHING
);
102 $key = $cache->makeKey( 'template', $templateName, $fastHash );
103 $code = $this->forceRecompile ?
null : $cache->get( $key );
106 $code = $this->compileForEval( $fileContents, $filename );
108 // Prefix the cached code with a keyed hash (64 hex chars) as an integrity check
109 $cache->set( $key, hash_hmac( 'sha256', $code, $secretKey ) . $code );
111 // Verify the integrity of the cached PHP code
112 $keyedHash = substr( $code, 0, 64 );
113 $code = substr( $code, 64 );
114 if ( $keyedHash !== hash_hmac( 'sha256', $code, $secretKey ) ) {
115 // Generate a notice if integrity check fails
116 trigger_error( "Template failed integrity check: {$filename}" );
119 // If there is no secret key available, don't use cache
121 $code = $this->compileForEval( $fileContents, $filename );
124 $renderer = eval( $code );
125 if ( !is_callable( $renderer ) ) {
126 throw new RuntimeException( "Requested template, {$templateName}, is not callable" );
128 $this->renderers
[$templateName] = $renderer;
133 * Wrapper for compile() function that verifies successful compilation and strips
134 * out the '<?php' part so that the code is ready for eval()
135 * @param string $fileContents Mustache code
136 * @param string $filename Name of the template
137 * @return string PHP code (without '<?php')
138 * @throws RuntimeException
140 protected function compileForEval( $fileContents, $filename ) {
141 // Compile the template into PHP code
142 $code = $this->compile( $fileContents );
145 throw new RuntimeException( "Could not compile template: {$filename}" );
148 // Strip the "<?php" added by lightncandy so that it can be eval()ed
149 if ( substr( $code, 0, 5 ) === '<?php' ) {
150 $code = substr( $code, 5 );
157 * Compile the Mustache code into PHP code using LightnCandy
158 * @param string $code Mustache code
159 * @return string PHP code (with '<?php')
160 * @throws RuntimeException
162 protected function compile( $code ) {
163 if ( !class_exists( 'LightnCandy' ) ) {
164 throw new RuntimeException( 'LightnCandy class not defined' );
166 return LightnCandy
::compile(
169 // Do not add more flags here without discussion.
170 // If you do add more flags, be sure to update unit tests as well.
171 'flags' => LightnCandy
::FLAG_ERROR_EXCEPTION
,
172 'basedir' => $this->templateDir
,
173 'fileext' => '.mustache',
179 * Returns HTML for a given template by calling the template function with the given args
182 * echo $templateParser->processTemplate(
185 * 'username' => $user->getName(),
186 * 'message' => 'Hello!'
190 * @param string $templateName The name of the template
192 * @param array $scopes
195 public function processTemplate( $templateName, $args, array $scopes = [] ) {
196 $template = $this->getTemplate( $templateName );
197 return call_user_func( $template, $args, $scopes );