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<?php
/*
* This file is part of Twig.
*
* (c) 2009 Fabien Potencier
* (c) 2009 Armin Ronacher
*
* For the full copyright and license information, please view the LICENSE
* file that was distributed with this source code.
*/
/**
* Default parser implementation.
*
* @package twig
* @author Fabien Potencier <fabien@symfony.com>
*/
class Twig_Parser implements Twig_ParserInterface
{
protected $stack = array();
protected $stream;
protected $parent;
protected $handlers;
protected $visitors;
protected $expressionParser;
protected $blocks;
protected $blockStack;
protected $macros;
protected $env;
protected $reservedMacroNames;
protected $importedFunctions;
protected $tmpVarCount;
protected $traits;
/**
* Constructor.
*
* @param Twig_Environment $env A Twig_Environment instance
*/
public function __construct(Twig_Environment $env)
{
$this->env = $env;
}
public function getEnvironment()
{
return $this->env;
}
public function getVarName()
{
return sprintf('__internal_%s_%d', substr($this->env->getTemplateClass($this->stream->getFilename()), strlen($this->env->getTemplateClassPrefix())), ++$this->tmpVarCount);
}
/**
* Converts a token stream to a node tree.
*
* @param Twig_TokenStream $stream A token stream instance
*
* @return Twig_Node_Module A node tree
*/
public function parse(Twig_TokenStream $stream)
{
// push all variables into the stack to keep the current state of the parser
$vars = get_object_vars($this);
unset($vars['stack'], $vars['env'], $vars['handlers'], $vars['visitors'], $vars['expressionParser']);
$this->stack[] = $vars;
$this->tmpVarCount = 0;
// tag handlers
if (null === $this->handlers) {
$this->handlers = $this->env->getTokenParsers();
$this->handlers->setParser($this);
}
// node visitors
if (null === $this->visitors) {
$this->visitors = $this->env->getNodeVisitors();
}
if (null === $this->expressionParser) {
$this->expressionParser = new Twig_ExpressionParser($this, $this->env->getUnaryOperators(), $this->env->getBinaryOperators());
}
$this->stream = $stream;
$this->parent = null;
$this->blocks = array();
$this->macros = array();
$this->traits = array();
$this->blockStack = array();
$this->importedFunctions = array(array());
try {
$body = $this->subparse(null);
if (null !== $this->parent) {
if (null === $body = $this->filterBodyNodes($body)) {
$body = new Twig_Node();
}
}
} catch (Twig_Error_Syntax $e) {
if (null === $e->getTemplateFile()) {
$e->setTemplateFile($this->stream->getFilename());
}
throw $e;
}
$node = new Twig_Node_Module(new Twig_Node_Body(array($body)), $this->parent, new Twig_Node($this->blocks), new Twig_Node($this->macros), new Twig_Node($this->traits), $this->stream->getFilename());
$traverser = new Twig_NodeTraverser($this->env, $this->visitors);
$node = $traverser->traverse($node);
// restore previous stack so previous parse() call can resume working
foreach (array_pop($this->stack) as $key => $val) {
$this->$key = $val;
}
return $node;
}
public function subparse($test, $dropNeedle = false)
{
$lineno = $this->getCurrentToken()->getLine();
$rv = array();
while (!$this->stream->isEOF()) {
switch ($this->getCurrentToken()->getType()) {
case Twig_Token::TEXT_TYPE:
$token = $this->stream->next();
$rv[] = new Twig_Node_Text($token->getValue(), $token->getLine());
break;
case Twig_Token::VAR_START_TYPE:
$token = $this->stream->next();
$expr = $this->expressionParser->parseExpression();
$this->stream->expect(Twig_Token::VAR_END_TYPE);
$rv[] = new Twig_Node_Print($expr, $token->getLine());
break;
case Twig_Token::BLOCK_START_TYPE:
$this->stream->next();
$token = $this->getCurrentToken();
if ($token->getType() !== Twig_Token::NAME_TYPE) {
throw new Twig_Error_Syntax('A block must start with a tag name', $token->getLine(), $this->stream->getFilename());
}
if (null !== $test && call_user_func($test, $token)) {
if ($dropNeedle) {
$this->stream->next();
}
if (1 === count($rv)) {
return $rv[0];
}
return new Twig_Node($rv, array(), $lineno);
}
$subparser = $this->handlers->getTokenParser($token->getValue());
if (null === $subparser) {
if (null !== $test) {
throw new Twig_Error_Syntax(sprintf('Unexpected tag name "%s" (expecting closing tag for the "%s" tag defined near line %s)', $token->getValue(), $test[0]->getTag(), $lineno), $token->getLine(), $this->stream->getFilename());
}
$message = sprintf('Unknown tag name "%s"', $token->getValue());
if ($alternatives = $this->env->computeAlternatives($token->getValue(), array_keys($this->env->getTags()))) {
$message = sprintf('%s. Did you mean "%s"', $message, implode('", "', $alternatives));
}
throw new Twig_Error_Syntax($message, $token->getLine(), $this->stream->getFilename());
}
$this->stream->next();
$node = $subparser->parse($token);
if (null !== $node) {
$rv[] = $node;
}
break;
default:
throw new Twig_Error_Syntax('Lexer or parser ended up in unsupported state.', -1, $this->stream->getFilename());
}
}
if (1 === count($rv)) {
return $rv[0];
}
return new Twig_Node($rv, array(), $lineno);
}
public function addHandler($name, $class)
{
$this->handlers[$name] = $class;
}
public function addNodeVisitor(Twig_NodeVisitorInterface $visitor)
{
$this->visitors[] = $visitor;
}
public function getBlockStack()
{
return $this->blockStack;
}
public function peekBlockStack()
{
return $this->blockStack[count($this->blockStack) - 1];
}
public function popBlockStack()
{
array_pop($this->blockStack);
}
public function pushBlockStack($name)
{
$this->blockStack[] = $name;
}
public function hasBlock($name)
{
return isset($this->blocks[$name]);
}
public function setBlock($name, $value)
{
$this->blocks[$name] = new Twig_Node_Body(array($value));
}
public function hasMacro($name)
{
return isset($this->macros[$name]);
}
public function setMacro($name, Twig_Node_Macro $node)
{
if (null === $this->reservedMacroNames) {
$this->reservedMacroNames = array();
$r = new ReflectionClass($this->env->getBaseTemplateClass());
foreach ($r->getMethods() as $method) {
$this->reservedMacroNames[] = $method->getName();
}
}
if (in_array($name, $this->reservedMacroNames)) {
throw new Twig_Error_Syntax(sprintf('"%s" cannot be used as a macro name as it is a reserved keyword', $name), $node->getLine());
}
$this->macros[$name] = $node;
}
public function addTrait($trait)
{
$this->traits[] = $trait;
}
public function hasTraits()
{
return count($this->traits) > 0;
}
public function addImportedFunction($alias, $name, Twig_Node_Expression $node)
{
$this->importedFunctions[0][$alias] = array('name' => $name, 'node' => $node);
}
public function getImportedFunction($alias)
{
foreach ($this->importedFunctions as $functions) {
if (isset($functions[$alias])) {
return $functions[$alias];
}
}
}
public function isMainScope()
{
return 1 === count($this->importedFunctions);
}
public function pushLocalScope()
{
array_unshift($this->importedFunctions, array());
}
public function popLocalScope()
{
array_shift($this->importedFunctions);
}
/**
* Gets the expression parser.
*
* @return Twig_ExpressionParser The expression parser
*/
public function getExpressionParser()
{
return $this->expressionParser;
}
public function getParent()
{
return $this->parent;
}
public function setParent($parent)
{
$this->parent = $parent;
}
/**
* Gets the token stream.
*
* @return Twig_TokenStream The token stream
*/
public function getStream()
{
return $this->stream;
}
/**
* Gets the current token.
*
* @return Twig_Token The current token
*/
public function getCurrentToken()
{
return $this->stream->getCurrent();
}
protected function filterBodyNodes(Twig_NodeInterface $node)
{
// check that the body does not contain non-empty output nodes
if (
($node instanceof Twig_Node_Text && !ctype_space($node->getAttribute('data')))
||
(!$node instanceof Twig_Node_Text && !$node instanceof Twig_Node_BlockReference && $node instanceof Twig_NodeOutputInterface)
) {
if (false !== strpos((string) $node, chr(0xEF).chr(0xBB).chr(0xBF))) {
throw new Twig_Error_Syntax('A template that extends another one cannot have a body but a byte order mark (BOM) has been detected; it must be removed.', $node->getLine(), $this->stream->getFilename());
} else {
throw new Twig_Error_Syntax('A template that extends another one cannot have a body.', $node->getLine(), $this->stream->getFilename());
}
}
// bypass "set" nodes as they "capture" the output
if ($node instanceof Twig_Node_Set) {
return $node;
}
if ($node instanceof Twig_NodeOutputInterface) {
return;
}
foreach ($node as $k => $n) {
if (null !== $n && null === $n = $this->filterBodyNodes($n)) {
$node->removeNode($k);
}
}
return $node;
}
}