<?php
/*
* This file is part of Mustache.php.
*
* (c) 2010-2017 Justin Hileman
*
* For the full copyright and license information, please view the LICENSE
* file that was distributed with this source code.
*/
/**
* Mustache Parser class.
*
* This class is responsible for turning a set of Mustache tokens into a parse tree.
*/
class Mustache_Parser
{
private $lineNum;
private $lineTokens;
private $pragmas;
private $defaultPragmas = array();
private $pragmaFilters;
private $pragmaBlocks;
private $pragmaDynamicNames;
/**
* Process an array of Mustache tokens and convert them into a parse tree.
*
* @param array $tokens Set of Mustache tokens
*
* @return array Mustache token parse tree
*/
public function parse(array $tokens = array())
{
$this->lineNum = -1;
$this->lineTokens = 0;
$this->pragmas = $this->defaultPragmas;
$this->pragmaFilters = isset($this->pragmas[Mustache_Engine::PRAGMA_FILTERS]);
$this->pragmaBlocks = isset($this->pragmas[Mustache_Engine::PRAGMA_BLOCKS]);
$this->pragmaDynamicNames = isset($this->pragmas[Mustache_Engine::PRAGMA_DYNAMIC_NAMES]);
return $this->buildTree($tokens);
}
/**
* Enable pragmas across all templates, regardless of the presence of pragma
* tags in the individual templates.
*
* @internal Users should set global pragmas in Mustache_Engine, not here :)
*
* @param string[] $pragmas
*/
public function setPragmas(array $pragmas)
{
$this->pragmas = array();
foreach ($pragmas as $pragma) {
$this->enablePragma($pragma);
}
$this->defaultPragmas = $this->pragmas;
}
/**
* Helper method for recursively building a parse tree.
*
* @throws Mustache_Exception_SyntaxException when nesting errors or mismatched section tags are encountered
*
* @param array &$tokens Set of Mustache tokens
* @param array $parent Parent token (default: null)
*
* @return array Mustache Token parse tree
*/
private function buildTree(array &$tokens, array $parent = null)
{
$nodes = array();
while (!empty($tokens)) {
$token = array_shift($tokens);
if ($token[Mustache_Tokenizer::LINE] === $this->lineNum) {
$this->lineTokens++;
} else {
$this->lineNum = $token[Mustache_Tokenizer::LINE];
$this->lineTokens = 0;
}
if ($token[Mustache_Tokenizer::TYPE] !== Mustache_Tokenizer::T_COMMENT) {
if ($this->pragmaDynamicNames && isset($token[Mustache_Tokenizer::NAME])) {
list($name, $isDynamic) = $this->getDynamicName($token);
if ($isDynamic) {
$token[Mustache_Tokenizer::NAME] = $name;
$token[Mustache_Tokenizer::DYNAMIC] = true;
}
}
if ($this->pragmaFilters && isset($token[Mustache_Tokenizer::NAME])) {
list($name, $filters) = $this->getNameAndFilters($token[Mustache_Tokenizer::NAME]);
if (!empty($filters)) {
$token[Mustache_Tokenizer::NAME] = $name;
$token[Mustache_Tokenizer::FILTERS] = $filters;
}
}
}
switch ($token[Mustache_Tokenizer::TYPE]) {
case Mustache_Tokenizer::T_DELIM_CHANGE:
$this->checkIfTokenIsAllowedInParent($parent, $token);
$this->clearStandaloneLines($nodes, $tokens);
break;
case Mustache_Tokenizer::T_SECTION:
case Mustache_Tokenizer::T_INVERTED:
$this->checkIfTokenIsAllowedInParent($parent, $token);
$this->clearStandaloneLines($nodes, $tokens);
$nodes[] = $this->buildTree($tokens, $token);
break;
case Mustache_Tokenizer::T_END_SECTION:
if (!isset($parent)) {
$msg = sprintf(
'Unexpected closing tag: /%s on line %d',
$token[Mustache_Tokenizer::NAME],
$token[Mustache_Tokenizer::LINE]
);
throw new Mustache_Exception_SyntaxException($msg, $token);
}
$sameName = $token[Mustache_Tokenizer::NAME] !== $parent[Mustache_Tokenizer::NAME];
$tokenDynamic = isset($token[Mustache_Tokenizer::DYNAMIC]) && $token[Mustache_Tokenizer::DYNAMIC];
$parentDynamic = isset($parent[Mustache_Tokenizer::DYNAMIC]) && $parent[Mustache_Tokenizer::DYNAMIC];
if ($sameName || ($tokenDynamic !== $parentDynamic)) {
$msg = sprintf(
'Nesting error: %s%s (on line %d) vs. %s%s (on line %d)',
$parentDynamic ? '*' : '',
$parent[Mustache_Tokenizer::NAME],
$parent[Mustache_Tokenizer::LINE],
$tokenDynamic ? '*' : '',
$token[Mustache_Tokenizer::NAME],
$token[Mustache_Tokenizer::LINE]
);
throw new Mustache_Exception_SyntaxException($msg, $token);
}
$this->clearStandaloneLines($nodes, $tokens);
$parent[Mustache_Tokenizer::END] = $token[Mustache_Tokenizer::INDEX];
$parent[Mustache_Tokenizer::NODES] = $nodes;
return $parent;
case Mustache_Tokenizer::T_PARTIAL:
$this->checkIfTokenIsAllowedInParent($parent, $token);
//store the whitespace prefix for laters!
if ($indent = $this->clearStandaloneLines($nodes, $tokens)) {
$token[Mustache_Tokenizer::INDENT] = $indent[Mustache_Tokenizer::VALUE];
}
$nodes[] = $token;
break;
case Mustache_Tokenizer::T_PARENT:
$this->checkIfTokenIsAllowedInParent($parent, $token);
$nodes[] = $this->buildTree($tokens, $token);
break;
case Mustache_Tokenizer::T_BLOCK_VAR:
if ($this->pragmaBlocks) {
// BLOCKS pragma is enabled, let's do this!
if (isset($parent) && $parent[Mustache_Tokenizer::TYPE] === Mustache_Tokenizer::T_PARENT) {
$token[Mustache_Tokenizer::TYPE] = Mustache_Tokenizer::T_BLOCK_ARG;
}
$this->clearStandaloneLines($nodes, $tokens);
$nodes[] = $this->buildTree($tokens, $token);
} else {
// pretend this was just a normal "escaped" token...
$token[Mustache_Tokenizer::TYPE] = Mustache_Tokenizer::T_ESCAPED;
// TODO: figure out how to figure out if there was a space after this dollar:
$token[Mustache_Tokenizer::NAME] = '$' . $token[Mustache_Tokenizer::NAME];
$nodes[] = $token;
}
break;
case Mustache_Tokenizer::T_PRAGMA:
$this->enablePragma($token[Mustache_Tokenizer::NAME]);
// no break
case Mustache_Tokenizer::T_COMMENT:
$this->clearStandaloneLines($nodes, $tokens);
$nodes[] = $token;
break;
default:
$nodes[] = $token;
break;
}
}
if (isset($parent)) {
$msg = sprintf(
'Missing closing tag: %s opened on line %d',
$parent[Mustache_Tokenizer::NAME],
$parent[Mustache_Tokenizer::LINE]
);
throw new Mustache_Exception_SyntaxException($msg, $parent);
}
return $nodes;
}
/**
* Clear standalone line tokens.
*
* Returns a whitespace token for indenting partials, if applicable.
*
* @param array $nodes Parsed nodes
* @param array $tokens Tokens to be parsed
*
* @return array|null Resulting indent token, if any
*/
private function clearStandaloneLines(array &$nodes, array &$tokens)
{
if ($this->lineTokens > 1) {
// this is the third or later node on this line, so it can't be standalone
return null;
}
$prev = null;
if ($this->lineTokens === 1) {
// this is the second node on this line, so it can't be standalone
// unless the previous node is whitespace.
if ($prev = end($nodes)) {
if (!$this->tokenIsWhitespace($prev)) {
return null;
}
}
}
if ($next = reset($tokens)) {
// If we're on a new line, bail.
if ($next[Mustache_Tokenizer::LINE] !== $this->lineNum) {
return null;
}
// If the next token isn't whitespace, bail.
if (!$this->tokenIsWhitespace($next)) {
return null;
}
if (count($tokens) !== 1) {
// Unless it's the last token in the template, the next token
// must end in newline for this to be standalone.
if (substr($next[Mustache_Tokenizer::VALUE], -1) !== "\n") {
return null;
}
}
// Discard the whitespace suffix
array_shift($tokens);
}
if ($prev) {
// Return the whitespace prefix, if any
return array_pop($nodes);
}
return null;
}
/**
* Check whether token is a whitespace token.
*
* True if token type is T_TEXT and value is all whitespace characters.
*
* @param array $token
*
* @return bool True if token is a whitespace token
*/
private function tokenIsWhitespace(array $token)
{
if ($token[Mustache_Tokenizer::TYPE] === Mustache_Tokenizer::T_TEXT) {
return preg_match('/^\s*$/', $token[Mustache_Tokenizer::VALUE]);
}
return false;
}
/**
* Check whether a token is allowed inside a parent tag.
*
* @throws Mustache_Exception_SyntaxException if an invalid token is found inside a parent tag
*
* @param array|null $parent
* @param array $token
*/
private function checkIfTokenIsAllowedInParent($parent, array $token)
{
if (isset($parent) && $parent[Mustache_Tokenizer::TYPE] === Mustache_Tokenizer::T_PARENT) {
throw new Mustache_Exception_SyntaxException('Illegal content in < parent tag', $token);
}
}
/**
* Parse dynamic names.
*
* @throws Mustache_Exception_SyntaxException when a tag does not allow *
* @throws Mustache_Exception_SyntaxException on multiple *s, or dots or filters with *
*/
private function getDynamicName(array $token)
{
$name = $token[Mustache_Tokenizer::NAME];
$isDynamic = false;
if (preg_match('/^\s*\*\s*/', $name)) {
$this->ensureTagAllowsDynamicNames($token);
$name = preg_replace('/^\s*\*\s*/', '', $name);
$isDynamic = true;
}
return array($name, $isDynamic);
}
/**
* Check whether the given token supports dynamic tag names.
*
* @throws Mustache_Exception_SyntaxException when a tag does not allow *
*
* @param array $token
*/
private function ensureTagAllowsDynamicNames(array $token)
{
switch ($token[Mustache_Tokenizer::TYPE]) {
case Mustache_Tokenizer::T_PARTIAL:
case Mustache_Tokenizer::T_PARENT:
case Mustache_Tokenizer::T_END_SECTION:
return;
}
$msg = sprintf(
'Invalid dynamic name: %s in %s tag',
$token[Mustache_Tokenizer::NAME],
Mustache_Tokenizer::getTagName($token[Mustache_Tokenizer::TYPE])
);
throw new Mustache_Exception_SyntaxException($msg, $token);
}
/**
* Split a tag name into name and filters.
*
* @param string $name
*
* @return array [Tag name, Array of filters]
*/
private function getNameAndFilters($name)
{
$filters = array_map('trim', explode('|', $name));
$name = array_shift($filters);
return array($name, $filters);
}
/**
* Enable a pragma.
*
* @param string $name
*/
private function enablePragma($name)
{
$this->pragmas[$name] = true;
switch ($name) {
case Mustache_Engine::PRAGMA_BLOCKS:
$this->pragmaBlocks = true;
break;
case Mustache_Engine::PRAGMA_FILTERS:
$this->pragmaFilters = true;
break;
case Mustache_Engine::PRAGMA_DYNAMIC_NAMES:
$this->pragmaDynamicNames = true;
break;
}
}
}
