TemplateParser::getTemplateFilename()   B
last analyzed

Complexity

Conditions 10
Paths 2

Size

Total Lines 19
Code Lines 12

Duplication

Lines 14
Ratio 73.68 %

Importance

Changes 0
Metric Value
cc 10
eloc 12
nc 2
nop 1
dl 14
loc 19
rs 7.2765
c 0
b 0
f 0

How to fix   Complexity   

Long Method

Small methods make your code easier to understand, in particular if combined with a good name. Besides, if your method is small, finding a good name is usually much easier.

For example, if you find yourself adding comments to a method's body, this is usually a good sign to extract the commented part to a new method, and use the comment as a starting point when coming up with a good name for this new method.

Commonly applied refactorings include:

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<?php
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/**
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 * Handles compiling Mustache templates into PHP rendering functions
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 *
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 * This program is free software; you can redistribute it and/or modify
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 * it under the terms of the GNU General Public License as published by
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 * the Free Software Foundation; either version 2 of the License, or
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 * (at your option) any later version.
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 *
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 * This program is distributed in the hope that it will be useful,
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 * but WITHOUT ANY WARRANTY; without even the implied warranty of
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 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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 * GNU General Public License for more details.
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 *
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 * You should have received a copy of the GNU General Public License along
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 * with this program; if not, write to the Free Software Foundation, Inc.,
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 * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
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 * http://www.gnu.org/copyleft/gpl.html
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 *
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 * @file
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 * @since 1.25
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 */
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class TemplateParser {
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	/**
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	 * @var string The path to the Mustache templates
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	 */
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	protected $templateDir;
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	/**
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	 * @var callable[] Array of cached rendering functions
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	 */
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	protected $renderers;
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	/**
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	 * @var bool Always compile template files
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	 */
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	protected $forceRecompile = false;
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	/**
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	 * @param string $templateDir
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	 * @param bool $forceRecompile
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	 */
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	public function __construct( $templateDir = null, $forceRecompile = false ) {
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		$this->templateDir = $templateDir ?: __DIR__ . '/templates';
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		$this->forceRecompile = $forceRecompile;
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	}
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	/**
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	 * Constructs the location of the the source Mustache template
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	 * @param string $templateName The name of the template
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	 * @return string
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	 * @throws UnexpectedValueException If $templateName attempts upwards directory traversal
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	 */
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	protected function getTemplateFilename( $templateName ) {
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		// Prevent upwards directory traversal using same methods as Title::secureAndSplit
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		if (
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			strpos( $templateName, '.' ) !== false &&
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			(
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				$templateName === '.' || $templateName === '..' ||
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				strpos( $templateName, './' ) === 0 ||
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				strpos( $templateName, '../' ) === 0 ||
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				strpos( $templateName, '/./' ) !== false ||
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				strpos( $templateName, '/../' ) !== false ||
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				substr( $templateName, -2 ) === '/.' ||
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				substr( $templateName, -3 ) === '/..'
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			)
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		) {
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			throw new UnexpectedValueException( "Malformed \$templateName: $templateName" );
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		}
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		return "{$this->templateDir}/{$templateName}.mustache";
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	}
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	/**
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	 * Returns a given template function if found, otherwise throws an exception.
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	 * @param string $templateName The name of the template (without file suffix)
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	 * @return callable
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	 * @throws RuntimeException
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	 */
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	protected function getTemplate( $templateName ) {
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		// If a renderer has already been defined for this template, reuse it
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		if ( isset( $this->renderers[$templateName] ) &&
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			is_callable( $this->renderers[$templateName] )
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		) {
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			return $this->renderers[$templateName];
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		}
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		$filename = $this->getTemplateFilename( $templateName );
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		if ( !file_exists( $filename ) ) {
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			throw new RuntimeException( "Could not locate template: {$filename}" );
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		}
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		// Read the template file
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		$fileContents = file_get_contents( $filename );
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		// Generate a quick hash for cache invalidation
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		$fastHash = md5( $fileContents );
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		// Fetch a secret key for building a keyed hash of the PHP code
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		$config = ConfigFactory::getDefaultInstance()->makeConfig( 'main' );
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		$secretKey = $config->get( 'SecretKey' );
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		if ( $secretKey ) {
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			// See if the compiled PHP code is stored in cache.
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			$cache = ObjectCache::getLocalServerInstance( CACHE_ANYTHING );
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			$key = $cache->makeKey( 'template', $templateName, $fastHash );
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			$code = $this->forceRecompile ? null : $cache->get( $key );
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			if ( !$code ) {
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				$code = $this->compileForEval( $fileContents, $filename );
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				// Prefix the cached code with a keyed hash (64 hex chars) as an integrity check
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				$cache->set( $key, hash_hmac( 'sha256', $code, $secretKey ) . $code );
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			} else {
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				// Verify the integrity of the cached PHP code
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				$keyedHash = substr( $code, 0, 64 );
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				$code = substr( $code, 64 );
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				if ( $keyedHash !== hash_hmac( 'sha256', $code, $secretKey ) ) {
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					// Generate a notice if integrity check fails
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					trigger_error( "Template failed integrity check: {$filename}" );
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				}
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			}
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		// If there is no secret key available, don't use cache
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		} else {
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			$code = $this->compileForEval( $fileContents, $filename );
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		}
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		$renderer = eval( $code );
0 ignored issues
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Coding Style introduced by
It is generally not recommended to use eval unless absolutely required.

On one hand, eval might be exploited by malicious users if they somehow manage to inject dynamic content. On the other hand, with the emergence of faster PHP runtimes like the HHVM, eval prevents some optimization that they perform.

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		if ( !is_callable( $renderer ) ) {
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			throw new RuntimeException( "Requested template, {$templateName}, is not callable" );
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		}
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		$this->renderers[$templateName] = $renderer;
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		return $renderer;
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	}
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	/**
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	 * Wrapper for compile() function that verifies successful compilation and strips
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	 * out the '<?php' part so that the code is ready for eval()
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	 * @param string $fileContents Mustache code
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	 * @param string $filename Name of the template
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	 * @return string PHP code (without '<?php')
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	 * @throws RuntimeException
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	 */
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	protected function compileForEval( $fileContents, $filename ) {
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		// Compile the template into PHP code
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		$code = $this->compile( $fileContents );
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		if ( !$code ) {
0 ignored issues
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Bug Best Practice introduced by
The expression $code of type false|string is loosely compared to false; this is ambiguous if the string can be empty. You might want to explicitly use === false instead.

In PHP, under loose comparison (like ==, or !=, or switch conditions), values of different types might be equal.

For string values, the empty string '' is a special case, in particular the following results might be unexpected:

''   == false // true
''   == null  // true
'ab' == false // false
'ab' == null  // false

// It is often better to use strict comparison
'' === false // false
'' === null  // false
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			throw new RuntimeException( "Could not compile template: {$filename}" );
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		}
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		// Strip the "<?php" added by lightncandy so that it can be eval()ed
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		if ( substr( $code, 0, 5 ) === '<?php' ) {
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			$code = substr( $code, 5 );
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		}
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		return $code;
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	}
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	/**
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	 * Compile the Mustache code into PHP code using LightnCandy
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	 * @param string $code Mustache code
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	 * @return string PHP code (with '<?php')
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	 * @throws RuntimeException
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	 */
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	protected function compile( $code ) {
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		if ( !class_exists( 'LightnCandy' ) ) {
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			throw new RuntimeException( 'LightnCandy class not defined' );
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		}
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		return LightnCandy::compile(
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			$code,
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			[
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				// Do not add more flags here without discussion.
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				// If you do add more flags, be sure to update unit tests as well.
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				'flags' => LightnCandy::FLAG_ERROR_EXCEPTION,
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				'basedir' => $this->templateDir,
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				'fileext' => '.mustache',
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			]
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		);
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	}
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	/**
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	 * Returns HTML for a given template by calling the template function with the given args
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	 *
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	 * @code
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	 *     echo $templateParser->processTemplate(
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	 *         'ExampleTemplate',
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	 *         [
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	 *             'username' => $user->getName(),
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	 *             'message' => 'Hello!'
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	 *         ]
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	 *     );
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	 * @endcode
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	 * @param string $templateName The name of the template
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	 * @param mixed $args
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	 * @param array $scopes
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	 * @return string
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	 */
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	public function processTemplate( $templateName, $args, array $scopes = [] ) {
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		$template = $this->getTemplate( $templateName );
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		return call_user_func( $template, $args, $scopes );
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	}
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}
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