Documentation & API reference
Parser.php
Same filename in this branch
Namespace
Symfony\Component\YamlFile
drupal/core/vendor/symfony/yaml/Symfony/Component/Yaml/Parser.phpView source
<?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\Yaml;
use Symfony\Component\Yaml\Exception\ParseException;
/**
* Parser parses YAML strings to convert them to PHP arrays.
*
* @author Fabien Potencier <fabien@symfony.com>
*/
class Parser {
private $offset = 0;
private $lines = array();
private $currentLineNb = -1;
private $currentLine = '';
private $refs = array();
/**
* Constructor
*
* @param integer $offset The offset of YAML document (used for line numbers in error messages)
*/
public function __construct($offset = 0) {
$this->offset = $offset;
}
/**
* Parses a YAML string to a PHP value.
*
* @param string $value A YAML string
*
* @return mixed A PHP value
*
* @throws ParseException If the YAML is not valid
*/
public function parse($value) {
$this->currentLineNb = -1;
$this->currentLine = '';
$this->lines = explode("\n", $this
->cleanup($value));
if (function_exists('mb_detect_encoding') && false === mb_detect_encoding($value, 'UTF-8', true)) {
throw new ParseException('The YAML value does not appear to be valid UTF-8.');
}
if (function_exists('mb_internal_encoding') && (int) ini_get('mbstring.func_overload') & 2) {
$mbEncoding = mb_internal_encoding();
mb_internal_encoding('UTF-8');
}
$data = array();
$context = null;
while ($this
->moveToNextLine()) {
if ($this
->isCurrentLineEmpty()) {
continue;
}
// tab?
if ("\t" === $this->currentLine[0]) {
throw new ParseException('A YAML file cannot contain tabs as indentation.', $this
->getRealCurrentLineNb() + 1, $this->currentLine);
}
$isRef = $isInPlace = $isProcessed = false;
if (preg_match('#^\\-((?P<leadspaces>\\s+)(?P<value>.+?))?\\s*$#u', $this->currentLine, $values)) {
if ($context && 'mapping' == $context) {
throw new ParseException('You cannot define a sequence item when in a mapping');
}
$context = 'sequence';
if (isset($values['value']) && preg_match('#^&(?P<ref>[^ ]+) *(?P<value>.*)#u', $values['value'], $matches)) {
$isRef = $matches['ref'];
$values['value'] = $matches['value'];
}
// array
if (!isset($values['value']) || '' == trim($values['value'], ' ') || 0 === strpos(ltrim($values['value'], ' '), '#')) {
$c = $this
->getRealCurrentLineNb() + 1;
$parser = new Parser($c);
$parser->refs =& $this->refs;
$data[] = $parser
->parse($this
->getNextEmbedBlock());
}
else {
if (isset($values['leadspaces']) && ' ' == $values['leadspaces'] && preg_match('#^(?P<key>' . Inline::REGEX_QUOTED_STRING . '|[^ \'"\\{\\[].*?) *\\:(\\s+(?P<value>.+?))?\\s*$#u', $values['value'], $matches)) {
// this is a compact notation element, add to next block and parse
$c = $this
->getRealCurrentLineNb();
$parser = new Parser($c);
$parser->refs =& $this->refs;
$block = $values['value'];
if (!$this
->isNextLineIndented()) {
$block .= "\n" . $this
->getNextEmbedBlock($this
->getCurrentLineIndentation() + 2);
}
$data[] = $parser
->parse($block);
}
else {
$data[] = $this
->parseValue($values['value']);
}
}
}
elseif (preg_match('#^(?P<key>' . Inline::REGEX_QUOTED_STRING . '|[^ \'"\\[\\{].*?) *\\:(\\s+(?P<value>.+?))?\\s*$#u', $this->currentLine, $values)) {
if ($context && 'sequence' == $context) {
throw new ParseException('You cannot define a mapping item when in a sequence');
}
$context = 'mapping';
try {
$key = Inline::parseScalar($values['key']);
} catch (ParseException $e) {
$e
->setParsedLine($this
->getRealCurrentLineNb() + 1);
$e
->setSnippet($this->currentLine);
throw $e;
}
if ('<<' === $key) {
if (isset($values['value']) && 0 === strpos($values['value'], '*')) {
$isInPlace = substr($values['value'], 1);
if (!array_key_exists($isInPlace, $this->refs)) {
throw new ParseException(sprintf('Reference "%s" does not exist.', $isInPlace), $this
->getRealCurrentLineNb() + 1, $this->currentLine);
}
}
else {
if (isset($values['value']) && $values['value'] !== '') {
$value = $values['value'];
}
else {
$value = $this
->getNextEmbedBlock();
}
$c = $this
->getRealCurrentLineNb() + 1;
$parser = new Parser($c);
$parser->refs =& $this->refs;
$parsed = $parser
->parse($value);
$merged = array();
if (!is_array($parsed)) {
throw new ParseException('YAML merge keys used with a scalar value instead of an array.', $this
->getRealCurrentLineNb() + 1, $this->currentLine);
}
elseif (isset($parsed[0])) {
// Numeric array, merge individual elements
foreach (array_reverse($parsed) as $parsedItem) {
if (!is_array($parsedItem)) {
throw new ParseException('Merge items must be arrays.', $this
->getRealCurrentLineNb() + 1, $parsedItem);
}
$merged = array_merge($parsedItem, $merged);
}
}
else {
// Associative array, merge
$merged = array_merge($merged, $parsed);
}
$isProcessed = $merged;
}
}
elseif (isset($values['value']) && preg_match('#^&(?P<ref>[^ ]+) *(?P<value>.*)#u', $values['value'], $matches)) {
$isRef = $matches['ref'];
$values['value'] = $matches['value'];
}
if ($isProcessed) {
// Merge keys
$data = $isProcessed;
// hash
}
elseif (!isset($values['value']) || '' == trim($values['value'], ' ') || 0 === strpos(ltrim($values['value'], ' '), '#')) {
// if next line is less indented or equal, then it means that the current value is null
if ($this
->isNextLineIndented() && !$this
->isNextLineUnIndentedCollection()) {
$data[$key] = null;
}
else {
$c = $this
->getRealCurrentLineNb() + 1;
$parser = new Parser($c);
$parser->refs =& $this->refs;
$data[$key] = $parser
->parse($this
->getNextEmbedBlock());
}
}
else {
if ($isInPlace) {
$data = $this->refs[$isInPlace];
}
else {
$data[$key] = $this
->parseValue($values['value']);
}
}
}
else {
// 1-liner followed by newline
if (2 == count($this->lines) && empty($this->lines[1])) {
try {
$value = Inline::parse($this->lines[0]);
} catch (ParseException $e) {
$e
->setParsedLine($this
->getRealCurrentLineNb() + 1);
$e
->setSnippet($this->currentLine);
throw $e;
}
if (is_array($value)) {
$first = reset($value);
if (is_string($first) && 0 === strpos($first, '*')) {
$data = array();
foreach ($value as $alias) {
$data[] = $this->refs[substr($alias, 1)];
}
$value = $data;
}
}
if (isset($mbEncoding)) {
mb_internal_encoding($mbEncoding);
}
return $value;
}
switch (preg_last_error()) {
case PREG_INTERNAL_ERROR:
$error = 'Internal PCRE error.';
break;
case PREG_BACKTRACK_LIMIT_ERROR:
$error = 'pcre.backtrack_limit reached.';
break;
case PREG_RECURSION_LIMIT_ERROR:
$error = 'pcre.recursion_limit reached.';
break;
case PREG_BAD_UTF8_ERROR:
$error = 'Malformed UTF-8 data.';
break;
case PREG_BAD_UTF8_OFFSET_ERROR:
$error = 'Offset doesn\'t correspond to the begin of a valid UTF-8 code point.';
break;
default:
$error = 'Unable to parse.';
}
throw new ParseException($error, $this
->getRealCurrentLineNb() + 1, $this->currentLine);
}
if ($isRef) {
$this->refs[$isRef] = end($data);
}
}
if (isset($mbEncoding)) {
mb_internal_encoding($mbEncoding);
}
return empty($data) ? null : $data;
}
/**
* Returns the current line number (takes the offset into account).
*
* @return integer The current line number
*/
private function getRealCurrentLineNb() {
return $this->currentLineNb + $this->offset;
}
/**
* Returns the current line indentation.
*
* @return integer The current line indentation
*/
private function getCurrentLineIndentation() {
return strlen($this->currentLine) - strlen(ltrim($this->currentLine, ' '));
}
/**
* Returns the next embed block of YAML.
*
* @param integer $indentation The indent level at which the block is to be read, or null for default
*
* @return string A YAML string
*
* @throws ParseException When indentation problem are detected
*/
private function getNextEmbedBlock($indentation = null) {
$this
->moveToNextLine();
if (null === $indentation) {
$newIndent = $this
->getCurrentLineIndentation();
$unindentedEmbedBlock = $this
->isStringUnIndentedCollectionItem($this->currentLine);
if (!$this
->isCurrentLineEmpty() && 0 === $newIndent && !$unindentedEmbedBlock) {
throw new ParseException('Indentation problem.', $this
->getRealCurrentLineNb() + 1, $this->currentLine);
}
}
else {
$newIndent = $indentation;
}
$data = array(
substr($this->currentLine, $newIndent),
);
$isItUnindentedCollection = $this
->isStringUnIndentedCollectionItem($this->currentLine);
while ($this
->moveToNextLine()) {
if ($isItUnindentedCollection && !$this
->isStringUnIndentedCollectionItem($this->currentLine)) {
$this
->moveToPreviousLine();
break;
}
if ($this
->isCurrentLineEmpty()) {
if ($this
->isCurrentLineBlank()) {
$data[] = substr($this->currentLine, $newIndent);
}
continue;
}
$indent = $this
->getCurrentLineIndentation();
if (preg_match('#^(?P<text> *)$#', $this->currentLine, $match)) {
// empty line
$data[] = $match['text'];
}
elseif ($indent >= $newIndent) {
$data[] = substr($this->currentLine, $newIndent);
}
elseif (0 == $indent) {
$this
->moveToPreviousLine();
break;
}
else {
throw new ParseException('Indentation problem.', $this
->getRealCurrentLineNb() + 1, $this->currentLine);
}
}
return implode("\n", $data);
}
/**
* Moves the parser to the next line.
*
* @return Boolean
*/
private function moveToNextLine() {
if ($this->currentLineNb >= count($this->lines) - 1) {
return false;
}
$this->currentLine = $this->lines[++$this->currentLineNb];
return true;
}
/**
* Moves the parser to the previous line.
*/
private function moveToPreviousLine() {
$this->currentLine = $this->lines[--$this->currentLineNb];
}
/**
* Parses a YAML value.
*
* @param string $value A YAML value
*
* @return mixed A PHP value
*
* @throws ParseException When reference does not exist
*/
private function parseValue($value) {
if (0 === strpos($value, '*')) {
if (false !== ($pos = strpos($value, '#'))) {
$value = substr($value, 1, $pos - 2);
}
else {
$value = substr($value, 1);
}
if (!array_key_exists($value, $this->refs)) {
throw new ParseException(sprintf('Reference "%s" does not exist.', $value), $this->currentLine);
}
return $this->refs[$value];
}
if (preg_match('/^(?P<separator>\\||>)(?P<modifiers>\\+|\\-|\\d+|\\+\\d+|\\-\\d+|\\d+\\+|\\d+\\-)?(?P<comments> +#.*)?$/', $value, $matches)) {
$modifiers = isset($matches['modifiers']) ? $matches['modifiers'] : '';
return $this
->parseFoldedScalar($matches['separator'], preg_replace('#\\d+#', '', $modifiers), intval(abs($modifiers)));
}
try {
return Inline::parse($value);
} catch (ParseException $e) {
$e
->setParsedLine($this
->getRealCurrentLineNb() + 1);
$e
->setSnippet($this->currentLine);
throw $e;
}
}
/**
* Parses a folded scalar.
*
* @param string $separator The separator that was used to begin this folded scalar (| or >)
* @param string $indicator The indicator that was used to begin this folded scalar (+ or -)
* @param integer $indentation The indentation that was used to begin this folded scalar
*
* @return string The text value
*/
private function parseFoldedScalar($separator, $indicator = '', $indentation = 0) {
$separator = '|' == $separator ? "\n" : ' ';
$text = '';
$notEOF = $this
->moveToNextLine();
while ($notEOF && $this
->isCurrentLineBlank()) {
$text .= "\n";
$notEOF = $this
->moveToNextLine();
}
if (!$notEOF) {
return '';
}
if (!preg_match('#^(?P<indent>' . ($indentation ? str_repeat(' ', $indentation) : ' +') . ')(?P<text>.*)$#u', $this->currentLine, $matches)) {
$this
->moveToPreviousLine();
return '';
}
$textIndent = $matches['indent'];
$previousIndent = 0;
$text .= $matches['text'] . $separator;
while ($this->currentLineNb + 1 < count($this->lines)) {
$this
->moveToNextLine();
if (preg_match('#^(?P<indent> {' . strlen($textIndent) . ',})(?P<text>.+)$#u', $this->currentLine, $matches)) {
if (' ' == $separator && $previousIndent != $matches['indent']) {
$text = substr($text, 0, -1) . "\n";
}
$previousIndent = $matches['indent'];
$text .= str_repeat(' ', $diff = strlen($matches['indent']) - strlen($textIndent)) . $matches['text'] . ($diff ? "\n" : $separator);
}
elseif (preg_match('#^(?P<text> *)$#', $this->currentLine, $matches)) {
$text .= preg_replace('#^ {1,' . strlen($textIndent) . '}#', '', $matches['text']) . "\n";
}
else {
$this
->moveToPreviousLine();
break;
}
}
if (' ' == $separator) {
// replace last separator by a newline
$text = preg_replace('/ (\\n*)$/', "\n\$1", $text);
}
switch ($indicator) {
case '':
$text = preg_replace('#\\n+$#s', "\n", $text);
break;
case '+':
break;
case '-':
$text = preg_replace('#\\n+$#s', '', $text);
break;
}
return $text;
}
/**
* Returns true if the next line is indented.
*
* @return Boolean Returns true if the next line is indented, false otherwise
*/
private function isNextLineIndented() {
$currentIndentation = $this
->getCurrentLineIndentation();
$notEOF = $this
->moveToNextLine();
while ($notEOF && $this
->isCurrentLineEmpty()) {
$notEOF = $this
->moveToNextLine();
}
if (false === $notEOF) {
return false;
}
$ret = false;
if ($this
->getCurrentLineIndentation() <= $currentIndentation) {
$ret = true;
}
$this
->moveToPreviousLine();
return $ret;
}
/**
* Returns true if the current line is blank or if it is a comment line.
*
* @return Boolean Returns true if the current line is empty or if it is a comment line, false otherwise
*/
private function isCurrentLineEmpty() {
return $this
->isCurrentLineBlank() || $this
->isCurrentLineComment();
}
/**
* Returns true if the current line is blank.
*
* @return Boolean Returns true if the current line is blank, false otherwise
*/
private function isCurrentLineBlank() {
return '' == trim($this->currentLine, ' ');
}
/**
* Returns true if the current line is a comment line.
*
* @return Boolean Returns true if the current line is a comment line, false otherwise
*/
private function isCurrentLineComment() {
//checking explicitly the first char of the trim is faster than loops or strpos
$ltrimmedLine = ltrim($this->currentLine, ' ');
return $ltrimmedLine[0] === '#';
}
/**
* Cleanups a YAML string to be parsed.
*
* @param string $value The input YAML string
*
* @return string A cleaned up YAML string
*/
private function cleanup($value) {
$value = str_replace(array(
"\r\n",
"\r",
), "\n", $value);
if (!preg_match("#\n\$#", $value)) {
$value .= "\n";
}
// strip YAML header
$count = 0;
$value = preg_replace('#^\\%YAML[: ][\\d\\.]+.*\\n#su', '', $value, -1, $count);
$this->offset += $count;
// remove leading comments
$trimmedValue = preg_replace('#^(\\#.*?\\n)+#s', '', $value, -1, $count);
if ($count == 1) {
// items have been removed, update the offset
$this->offset += substr_count($value, "\n") - substr_count($trimmedValue, "\n");
$value = $trimmedValue;
}
// remove start of the document marker (---)
$trimmedValue = preg_replace('#^\\-\\-\\-.*?\\n#s', '', $value, -1, $count);
if ($count == 1) {
// items have been removed, update the offset
$this->offset += substr_count($value, "\n") - substr_count($trimmedValue, "\n");
$value = $trimmedValue;
// remove end of the document marker (...)
$value = preg_replace('#\\.\\.\\.\\s*$#s', '', $value);
}
return $value;
}
/**
* Returns true if the next line starts unindented collection
*
* @return Boolean Returns true if the next line starts unindented collection, false otherwise
*/
private function isNextLineUnIndentedCollection() {
$currentIndentation = $this
->getCurrentLineIndentation();
$notEOF = $this
->moveToNextLine();
while ($notEOF && $this
->isCurrentLineEmpty()) {
$notEOF = $this
->moveToNextLine();
}
if (false === $notEOF) {
return false;
}
$ret = false;
if ($this
->getCurrentLineIndentation() == $currentIndentation && $this
->isStringUnIndentedCollectionItem($this->currentLine)) {
$ret = true;
}
$this
->moveToPreviousLine();
return $ret;
}
/**
* Returns true if the string is unindented collection item
*
* @return Boolean Returns true if the string is unindented collection item, false otherwise
*/
private function isStringUnIndentedCollectionItem($string) {
return 0 === strpos($this->currentLine, '- ');
}
}