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<?php
/*
* This file is part of the Symfony package.
*
* (c) Fabien Potencier <fabien@symfony.com>
*
* For the full copyright and license information, please view the LICENSE
* file that was distributed with this source code.
*/
namespace Symfony\Component\Templating;
use Symfony\Component\Templating\Helper\HelperInterface;
use Symfony\Component\Templating\Loader\LoaderInterface;
use Symfony\Component\Templating\Storage\FileStorage;
use Symfony\Component\Templating\Storage\Storage;
use Symfony\Component\Templating\Storage\StringStorage;
/**
* PhpEngine is an engine able to render PHP templates.
*
* @author Fabien Potencier <fabien@symfony.com>
*/
class PhpEngine implements EngineInterface, \ArrayAccess
{
protected $loader;
protected $current;
/**
* @var HelperInterface[]
*/
protected $helpers = [];
protected $parents = [];
protected $stack = [];
protected $charset = 'UTF-8';
protected $cache = [];
protected $escapers = [];
protected static $escaperCache = [];
protected $globals = [];
protected $parser;
private $evalTemplate;
private $evalParameters;
/**
* @param HelperInterface[] $helpers An array of helper instances
*/
public function __construct(TemplateNameParserInterface $parser, LoaderInterface $loader, array $helpers = [])
{
$this->parser = $parser;
$this->loader = $loader;
$this->addHelpers($helpers);
$this->initializeEscapers();
foreach ($this->escapers as $context => $escaper) {
$this->setEscaper($context, $escaper);
}
}
/**
* {@inheritdoc}
*
* @throws \InvalidArgumentException if the template does not exist
*/
public function render($name, array $parameters = [])
{
$storage = $this->load($name);
$key = hash('sha256', serialize($storage));
$this->current = $key;
$this->parents[$key] = null;
// attach the global variables
$parameters = array_replace($this->getGlobals(), $parameters);
// render
if (false === $content = $this->evaluate($storage, $parameters)) {
throw new \RuntimeException(sprintf('The template "%s" cannot be rendered.', $this->parser->parse($name)));
}
// decorator
if ($this->parents[$key]) {
$slots = $this->get('slots');
$this->stack[] = $slots->get('_content');
$slots->set('_content', $content);
$content = $this->render($this->parents[$key], $parameters);
$slots->set('_content', array_pop($this->stack));
}
return $content;
}
/**
* {@inheritdoc}
*/
public function exists($name)
{
try {
$this->load($name);
} catch (\InvalidArgumentException $e) {
return false;
}
return true;
}
/**
* {@inheritdoc}
*/
public function supports($name)
{
$template = $this->parser->parse($name);
return 'php' === $template->get('engine');
}
/**
* Evaluates a template.
*
* @param array $parameters An array of parameters to pass to the template
*
* @return string|false The evaluated template, or false if the engine is unable to render the template
*
* @throws \InvalidArgumentException
*/
protected function evaluate(Storage $template, array $parameters = [])
{
$this->evalTemplate = $template;
$this->evalParameters = $parameters;
unset($template, $parameters);
if (isset($this->evalParameters['this'])) {
throw new \InvalidArgumentException('Invalid parameter (this).');
}
if (isset($this->evalParameters['view'])) {
throw new \InvalidArgumentException('Invalid parameter (view).');
}
// the view variable is exposed to the require file below
$view = $this;
if ($this->evalTemplate instanceof FileStorage) {
extract($this->evalParameters, \EXTR_SKIP);
$this->evalParameters = null;
ob_start();
require $this->evalTemplate;
$this->evalTemplate = null;
return ob_get_clean();
} elseif ($this->evalTemplate instanceof StringStorage) {
extract($this->evalParameters, \EXTR_SKIP);
$this->evalParameters = null;
ob_start();
eval('; ?>'.$this->evalTemplate.'<?php ;');
$this->evalTemplate = null;
return ob_get_clean();
}
return false;
}
/**
* Gets a helper value.
*
* @param string $name The helper name
*
* @return HelperInterface The helper value
*
* @throws \InvalidArgumentException if the helper is not defined
*/
#[\ReturnTypeWillChange]
public function offsetGet($name)
{
return $this->get($name);
}
/**
* Returns true if the helper is defined.
*
* @param string $name The helper name
*
* @return bool true if the helper is defined, false otherwise
*/
#[\ReturnTypeWillChange]
public function offsetExists($name)
{
return isset($this->helpers[$name]);
}
/**
* Sets a helper.
*
* @param HelperInterface $name The helper instance
* @param string $value An alias
*
* @return void
*/
#[\ReturnTypeWillChange]
public function offsetSet($name, $value)
{
$this->set($name, $value);
}
/**
* Removes a helper.
*
* @param string $name The helper name
*
* @return void
*
* @throws \LogicException
*/
#[\ReturnTypeWillChange]
public function offsetUnset($name)
{
throw new \LogicException(sprintf('You can\'t unset a helper (%s).', $name));
}
/**
* Adds some helpers.
*
* @param HelperInterface[] $helpers An array of helper
*/
public function addHelpers(array $helpers)
{
foreach ($helpers as $alias => $helper) {
$this->set($helper, \is_int($alias) ? null : $alias);
}
}
/**
* Sets the helpers.
*
* @param HelperInterface[] $helpers An array of helper
*/
public function setHelpers(array $helpers)
{
$this->helpers = [];
$this->addHelpers($helpers);
}
/**
* Sets a helper.
*
* @param string $alias An alias
*/
public function set(HelperInterface $helper, $alias = null)
{
$this->helpers[$helper->getName()] = $helper;
if (null !== $alias) {
$this->helpers[$alias] = $helper;
}
$helper->setCharset($this->charset);
}
/**
* Returns true if the helper if defined.
*
* @param string $name The helper name
*
* @return bool true if the helper is defined, false otherwise
*/
public function has($name)
{
return isset($this->helpers[$name]);
}
/**
* Gets a helper value.
*
* @param string $name The helper name
*
* @return HelperInterface The helper instance
*
* @throws \InvalidArgumentException if the helper is not defined
*/
public function get($name)
{
if (!isset($this->helpers[$name])) {
throw new \InvalidArgumentException(sprintf('The helper "%s" is not defined.', $name));
}
return $this->helpers[$name];
}
/**
* Decorates the current template with another one.
*
* @param string $template The decorator logical name
*/
public function extend($template)
{
$this->parents[$this->current] = $template;
}
/**
* Escapes a string by using the current charset.
*
* @param mixed $value A variable to escape
* @param string $context The context name
*
* @return mixed The escaped value
*/
public function escape($value, $context = 'html')
{
if (is_numeric($value)) {
return $value;
}
// If we deal with a scalar value, we can cache the result to increase
// the performance when the same value is escaped multiple times (e.g. loops)
if (is_scalar($value)) {
if (!isset(self::$escaperCache[$context][$value])) {
self::$escaperCache[$context][$value] = $this->getEscaper($context)($value);
}
return self::$escaperCache[$context][$value];
}
return $this->getEscaper($context)($value);
}
/**
* Sets the charset to use.
*
* @param string $charset The charset
*/
public function setCharset($charset)
{
if ('UTF8' === $charset = strtoupper($charset)) {
$charset = 'UTF-8'; // iconv on Windows requires "UTF-8" instead of "UTF8"
}
$this->charset = $charset;
foreach ($this->helpers as $helper) {
$helper->setCharset($this->charset);
}
}
/**
* Gets the current charset.
*
* @return string The current charset
*/
public function getCharset()
{
return $this->charset;
}
/**
* Adds an escaper for the given context.
*
* @param string $context The escaper context (html, js, ...)
* @param callable $escaper A PHP callable
*/
public function setEscaper($context, callable $escaper)
{
$this->escapers[$context] = $escaper;
self::$escaperCache[$context] = [];
}
/**
* Gets an escaper for a given context.
*
* @param string $context The context name
*
* @return callable A PHP callable
*
* @throws \InvalidArgumentException
*/
public function getEscaper($context)
{
if (!isset($this->escapers[$context])) {
throw new \InvalidArgumentException(sprintf('No registered escaper for context "%s".', $context));
}
return $this->escapers[$context];
}
/**
* @param string $name
* @param mixed $value
*/
public function addGlobal($name, $value)
{
$this->globals[$name] = $value;
}
/**
* Returns the assigned globals.
*
* @return array
*/
public function getGlobals()
{
return $this->globals;
}
/**
* Initializes the built-in escapers.
*
* Each function specifies a way for applying a transformation to a string
* passed to it. The purpose is for the string to be "escaped" so it is
* suitable for the format it is being displayed in.
*
* For example, the string: "It's required that you enter a username & password.\n"
* If this were to be displayed as HTML it would be sensible to turn the
* ampersand into '&amp;' and the apostrophe into '&aps;'. However if it were
* going to be used as a string in JavaScript to be displayed in an alert box
* it would be right to leave the string as-is, but c-escape the apostrophe and
* the new line.
*
* For each function there is a define to avoid problems with strings being
* incorrectly specified.
*/
protected function initializeEscapers()
{
$flags = \ENT_QUOTES | \ENT_SUBSTITUTE;
$this->escapers = [
'html' =>
/**
* Runs the PHP function htmlspecialchars on the value passed.
*
* @param string $value The value to escape
*
* @return string the escaped value
*/
function ($value) use ($flags) {
// Numbers and Boolean values get turned into strings which can cause problems
// with type comparisons (e.g. === or is_int() etc).
return \is_string($value) ? htmlspecialchars($value, $flags, $this->getCharset(), false) : $value;
},
'js' =>
/**
* A function that escape all non-alphanumeric characters
* into their \xHH or \uHHHH representations.
*
* @param string $value The value to escape
*
* @return string the escaped value
*/
function ($value) {
if ('UTF-8' != $this->getCharset()) {
$value = iconv($this->getCharset(), 'UTF-8', $value);
}
$callback = function ($matches) {
$char = $matches[0];
// \xHH
if (!isset($char[1])) {
return '\\x'.substr('00'.bin2hex($char), -2);
}
// \uHHHH
$char = iconv('UTF-8', 'UTF-16BE', $char);
return '\\u'.substr('0000'.bin2hex($char), -4);
};
if (null === $value = preg_replace_callback('#[^\p{L}\p{N} ]#u', $callback, $value)) {
throw new \InvalidArgumentException('The string to escape is not a valid UTF-8 string.');
}
if ('UTF-8' != $this->getCharset()) {
$value = iconv('UTF-8', $this->getCharset(), $value);
}
return $value;
},
];
self::$escaperCache = [];
}
/**
* Gets the loader associated with this engine.
*
* @return LoaderInterface A LoaderInterface instance
*/
public function getLoader()
{
return $this->loader;
}
/**
* Loads the given template.
*
* @param string|TemplateReferenceInterface $name A template name or a TemplateReferenceInterface instance
*
* @return Storage A Storage instance
*
* @throws \InvalidArgumentException if the template cannot be found
*/
protected function load($name)
{
$template = $this->parser->parse($name);
$key = $template->getLogicalName();
if (isset($this->cache[$key])) {
return $this->cache[$key];
}
$storage = $this->loader->load($template);
if (false === $storage) {
throw new \InvalidArgumentException(sprintf('The template "%s" does not exist.', $template));
}
return $this->cache[$key] = $storage;
}
}