Parser.php in Plug 7

Namespace

Symfony\Component\Yaml

File

lib/Symfony/yaml/Symfony/Component/Yaml/Parser.php

<?php

/*
 * This file is part of the Symfony package.
 *
 * (c) Fabien Potencier <[e-mail]>
 *
 * 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 <[e-mail]>
 */
class Parser {
  const FOLDED_SCALAR_PATTERN = '(?P<separator>\\||>)(?P<modifiers>\\+|\\-|\\d+|\\+\\d+|\\-\\d+|\\d+\\+|\\d+\\-)?(?P<comments> +#.*)?';
  private $offset = 0;
  private $lines = array();
  private $currentLineNb = -1;
  private $currentLine = '';
  private $refs = array();

  /**
   * Constructor.
   *
   * @param int $offset The offset of YAML document (used for line numbers in error messages)
   */
  public function __construct($offset = 0) {
    $this->offset = $offset;
  }

  /**
   * Parses a YAML string to a PHP value.
   *
   * @param string $value                  A YAML string
   * @param bool   $exceptionOnInvalidType true if an exception must be thrown on invalid types (a PHP resource or object), false otherwise
   * @param bool   $objectSupport          true if object support is enabled, false otherwise
   * @param bool   $objectForMap           true if maps should return a stdClass instead of array()
   *
   * @return mixed A PHP value
   *
   * @throws ParseException If the YAML is not valid
   */
  public function parse($value, $exceptionOnInvalidType = false, $objectSupport = false, $objectForMap = false) {
    if (!preg_match('//u', $value)) {
      throw new ParseException('The YAML value does not appear to be valid UTF-8.');
    }
    $this->currentLineNb = -1;
    $this->currentLine = '';
    $value = $this
      ->cleanup($value);
    $this->lines = explode("\n", $value);
    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;
    $allowOverwrite = false;
    while ($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 = $mergeNode = false;
      if (preg_match('#^\\-((?P<leadspaces>\\s+)(?P<value>.+?))?\\s*$#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;
          $parser = new self($c);
          $parser->refs =& $this->refs;
          $data[] = $parser
            ->parse($this
            ->getNextEmbedBlock(null, true), $exceptionOnInvalidType, $objectSupport, $objectForMap);
        }
        else {
          if (isset($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();
            $parser = new self($c);
            $parser->refs =& $this->refs;
            $block = $values['value'];
            if ($this
              ->isNextLineIndented()) {
              $block .= "\n" . $this
                ->getNextEmbedBlock($this
                ->getCurrentLineIndentation() + strlen($values['leadspaces']) + 1);
            }
            $data[] = $parser
              ->parse($block, $exceptionOnInvalidType, $objectSupport, $objectForMap);
          }
          else {
            $data[] = $this
              ->parseValue($values['value'], $exceptionOnInvalidType, $objectSupport, $objectForMap);
          }
        }
      }
      elseif (preg_match('#^(?P<key>' . Inline::REGEX_QUOTED_STRING . '|[^ \'"\\[\\{].*?) *\\:(\\s+(?P<value>.+?))?\\s*$#u', $this->currentLine, $values) && (false === strpos($values['key'], ' #') || in_array($values['key'][0], array(
        '"',
        "'",
      )))) {
        if ($context && 'sequence' == $context) {
          throw new ParseException('You cannot define a mapping item when in a sequence');
        }
        $context = 'mapping';

        // force correct settings
        Inline::parse(null, $exceptionOnInvalidType, $objectSupport, $objectForMap, $this->refs);
        try {
          $key = Inline::parseScalar($values['key']);
        } catch (ParseException $e) {
          $e
            ->setParsedLine($this
            ->getRealCurrentLineNb() + 1);
          $e
            ->setSnippet($this->currentLine);
          throw $e;
        }
        if ('<<' === $key) {
          $mergeNode = true;
          $allowOverwrite = true;
          if (isset($values['value']) && 0 === strpos($values['value'], '*')) {
            $refName = substr($values['value'], 1);
            if (!array_key_exists($refName, $this->refs)) {
              throw new ParseException(sprintf('Reference "%s" does not exist.', $refName), $this
                ->getRealCurrentLineNb() + 1, $this->currentLine);
            }
            $refValue = $this->refs[$refName];
            if (!is_array($refValue)) {
              throw new ParseException('YAML merge keys used with a scalar value instead of an array.', $this
                ->getRealCurrentLineNb() + 1, $this->currentLine);
            }
            foreach ($refValue as $key => $value) {
              if (!isset($data[$key])) {
                $data[$key] = $value;
              }
            }
          }
          else {
            if (isset($values['value']) && $values['value'] !== '') {
              $value = $values['value'];
            }
            else {
              $value = $this
                ->getNextEmbedBlock();
            }
            $c = $this
              ->getRealCurrentLineNb() + 1;
            $parser = new self($c);
            $parser->refs =& $this->refs;
            $parsed = $parser
              ->parse($value, $exceptionOnInvalidType, $objectSupport, $objectForMap);
            if (!is_array($parsed)) {
              throw new ParseException('YAML merge keys used with a scalar value instead of an array.', $this
                ->getRealCurrentLineNb() + 1, $this->currentLine);
            }
            if (isset($parsed[0])) {

              // If the value associated with the merge key is a sequence, then this sequence is expected to contain mapping nodes
              // and each of these nodes is merged in turn according to its order in the sequence. Keys in mapping nodes earlier
              // in the sequence override keys specified in later mapping nodes.
              foreach ($parsed as $parsedItem) {
                if (!is_array($parsedItem)) {
                  throw new ParseException('Merge items must be arrays.', $this
                    ->getRealCurrentLineNb() + 1, $parsedItem);
                }
                foreach ($parsedItem as $key => $value) {
                  if (!isset($data[$key])) {
                    $data[$key] = $value;
                  }
                }
              }
            }
            else {

              // If the value associated with the key is a single mapping node, each of its key/value pairs is inserted into the
              // current mapping, unless the key already exists in it.
              foreach ($parsed as $key => $value) {
                if (!isset($data[$key])) {
                  $data[$key] = $value;
                }
              }
            }
          }
        }
        elseif (isset($values['value']) && preg_match('#^&(?P<ref>[^ ]+) *(?P<value>.*)#u', $values['value'], $matches)) {
          $isRef = $matches['ref'];
          $values['value'] = $matches['value'];
        }
        if ($mergeNode) {

          // Merge keys
        }
        elseif (!isset($values['value']) || '' == trim($values['value'], ' ') || 0 === strpos(ltrim($values['value'], ' '), '#')) {

          // hash
          // if next line is less indented or equal, then it means that the current value is null
          if (!$this
            ->isNextLineIndented() && !$this
            ->isNextLineUnIndentedCollection()) {

            // Spec: Keys MUST be unique; first one wins.
            // But overwriting is allowed when a merge node is used in current block.
            if ($allowOverwrite || !isset($data[$key])) {
              $data[$key] = null;
            }
          }
          else {
            $c = $this
              ->getRealCurrentLineNb() + 1;
            $parser = new self($c);
            $parser->refs =& $this->refs;
            $value = $parser
              ->parse($this
              ->getNextEmbedBlock(), $exceptionOnInvalidType, $objectSupport, $objectForMap);

            // Spec: Keys MUST be unique; first one wins.
            // But overwriting is allowed when a merge node is used in current block.
            if ($allowOverwrite || !isset($data[$key])) {
              $data[$key] = $value;
            }
          }
        }
        else {
          $value = $this
            ->parseValue($values['value'], $exceptionOnInvalidType, $objectSupport, $objectForMap);

          // Spec: Keys MUST be unique; first one wins.
          // But overwriting is allowed when a merge node is used in current block.
          if ($allowOverwrite || !isset($data[$key])) {
            $data[$key] = $value;
          }
        }
      }
      else {

        // multiple documents are not supported
        if ('---' === $this->currentLine) {
          throw new ParseException('Multiple documents are not supported.');
        }

        // 1-liner optionally followed by newline(s)
        if ($this->lines[0] === trim($value)) {
          try {
            $value = Inline::parse($this->lines[0], $exceptionOnInvalidType, $objectSupport, $objectForMap, $this->refs);
          } 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 int The current line number
   */
  private function getRealCurrentLineNb() {
    return $this->currentLineNb + $this->offset;
  }

  /**
   * Returns the current line indentation.
   *
   * @return int The current line indentation
   */
  private function getCurrentLineIndentation() {
    return strlen($this->currentLine) - strlen(ltrim($this->currentLine, ' '));
  }

  /**
   * Returns the next embed block of YAML.
   *
   * @param int  $indentation The indent level at which the block is to be read, or null for default
   * @param bool $inSequence  True if the enclosing data structure is a sequence
   *
   * @return string A YAML string
   *
   * @throws ParseException When indentation problem are detected
   */
  private function getNextEmbedBlock($indentation = null, $inSequence = false) {
    $oldLineIndentation = $this
      ->getCurrentLineIndentation();
    if (!$this
      ->moveToNextLine()) {
      return;
    }
    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;
    }
    $data = array();
    if ($this
      ->getCurrentLineIndentation() >= $newIndent) {
      $data[] = substr($this->currentLine, $newIndent);
    }
    else {
      $this
        ->moveToPreviousLine();
      return;
    }
    if ($inSequence && $oldLineIndentation === $newIndent && '-' === $data[0][0]) {

      // the previous line contained a dash but no item content, this line is a sequence item with the same indentation
      // and therefore no nested list or mapping
      $this
        ->moveToPreviousLine();
      return;
    }
    $isItUnindentedCollection = $this
      ->isStringUnIndentedCollectionItem($this->currentLine);

    // Comments must not be removed inside a string block (ie. after a line ending with "|")
    $removeCommentsPattern = '~' . self::FOLDED_SCALAR_PATTERN . '$~';
    $removeComments = !preg_match($removeCommentsPattern, $this->currentLine);
    while ($this
      ->moveToNextLine()) {
      $indent = $this
        ->getCurrentLineIndentation();
      if ($indent === $newIndent) {
        $removeComments = !preg_match($removeCommentsPattern, $this->currentLine);
      }
      if ($isItUnindentedCollection && !$this
        ->isStringUnIndentedCollectionItem($this->currentLine) && $newIndent === $indent) {
        $this
          ->moveToPreviousLine();
        break;
      }
      if ($this
        ->isCurrentLineBlank()) {
        $data[] = substr($this->currentLine, $newIndent);
        continue;
      }
      if ($removeComments && $this
        ->isCurrentLineComment()) {
        continue;
      }
      if ($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 bool
   */
  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
   * @param bool   $exceptionOnInvalidType True if an exception must be thrown on invalid types false otherwise
   * @param bool   $objectSupport          True if object support is enabled, false otherwise
   * @param bool   $objectForMap           true if maps should return a stdClass instead of array()
   *
   * @return mixed A PHP value
   *
   * @throws ParseException When reference does not exist
   */
  private function parseValue($value, $exceptionOnInvalidType, $objectSupport, $objectForMap) {
    if (0 === strpos($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('/^' . self::FOLDED_SCALAR_PATTERN . '$/', $value, $matches)) {
      $modifiers = isset($matches['modifiers']) ? $matches['modifiers'] : '';
      return $this
        ->parseFoldedScalar($matches['separator'], preg_replace('#\\d+#', '', $modifiers), (int) abs($modifiers));
    }
    try {
      return Inline::parse($value, $exceptionOnInvalidType, $objectSupport, $objectForMap, $this->refs);
    } 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 int    $indentation The indentation that was used to begin this folded scalar
   *
   * @return string The text value
   */
  private function parseFoldedScalar($separator, $indicator = '', $indentation = 0) {
    $notEOF = $this
      ->moveToNextLine();
    if (!$notEOF) {
      return '';
    }
    $isCurrentLineBlank = $this
      ->isCurrentLineBlank();
    $text = '';

    // leading blank lines are consumed before determining indentation
    while ($notEOF && $isCurrentLineBlank) {

      // newline only if not EOF
      if ($notEOF = $this
        ->moveToNextLine()) {
        $text .= "\n";
        $isCurrentLineBlank = $this
          ->isCurrentLineBlank();
      }
    }

    // determine indentation if not specified
    if (0 === $indentation) {
      if (preg_match('/^ +/', $this->currentLine, $matches)) {
        $indentation = strlen($matches[0]);
      }
    }
    if ($indentation > 0) {
      $pattern = sprintf('/^ {%d}(.*)$/', $indentation);
      while ($notEOF && ($isCurrentLineBlank || preg_match($pattern, $this->currentLine, $matches))) {
        if ($isCurrentLineBlank) {
          $text .= substr($this->currentLine, $indentation);
        }
        else {
          $text .= $matches[1];
        }

        // newline only if not EOF
        if ($notEOF = $this
          ->moveToNextLine()) {
          $text .= "\n";
          $isCurrentLineBlank = $this
            ->isCurrentLineBlank();
        }
      }
    }
    elseif ($notEOF) {
      $text .= "\n";
    }
    if ($notEOF) {
      $this
        ->moveToPreviousLine();
    }

    // replace all non-trailing single newlines with spaces in folded blocks
    if ('>' === $separator) {
      preg_match('/(\\n*)$/', $text, $matches);
      $text = preg_replace('/(?<!\\n)\\n(?!\\n)/', ' ', rtrim($text, "\n"));
      $text .= $matches[1];
    }

    // deal with trailing newlines as indicated
    if ('' === $indicator) {
      $text = preg_replace('/\\n+$/', "\n", $text);
    }
    elseif ('-' === $indicator) {
      $text = preg_replace('/\\n+$/', '', $text);
    }
    return $text;
  }

  /**
   * Returns true if the next line is indented.
   *
   * @return bool Returns true if the next line is indented, false otherwise
   */
  private function isNextLineIndented() {
    $currentIndentation = $this
      ->getCurrentLineIndentation();
    $EOF = !$this
      ->moveToNextLine();
    while (!$EOF && $this
      ->isCurrentLineEmpty()) {
      $EOF = !$this
        ->moveToNextLine();
    }
    if ($EOF) {
      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 bool 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 bool 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 bool 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);

    // strip YAML header
    $count = 0;
    $value = preg_replace('#^\\%YAML[: ][\\d\\.]+.*\\n#u', '', $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 (...)
      $value = preg_replace('#\\.\\.\\.\\s*$#', '', $value);
    }
    return $value;
  }

  /**
   * Returns true if the next line starts unindented collection.
   *
   * @return bool 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 un-indented collection item.
   *
   * @return bool Returns true if the string is un-indented collection item, false otherwise
   */
  private function isStringUnIndentedCollectionItem() {
    return 0 === strpos($this->currentLine, '- ');
  }

}

Classes

Name	Description
Parser	Parser parses YAML strings to convert them to PHP arrays.