comparison core/lib/Drupal/Component/Gettext/PoHeader.php @ 0:4c8ae668cc8c

Initial import (non-working)

+<?php
+
+namespace Drupal\Component\Gettext;
+
+/**
+ * Gettext PO header handler.
+ *
+ * Possible Gettext PO header elements are explained in
+ * http://www.gnu.org/software/gettext/manual/gettext.html#Header-Entry,
+ * but we only support a subset of these directly.
+ *
+ * Example header:
+ *
+ * "Project-Id-Version: Drupal core (7.11)\n"
+ * "POT-Creation-Date: 2012-02-12 22:59+0000\n"
+ * "PO-Revision-Date: YYYY-mm-DD HH:MM+ZZZZ\n"
+ * "Language-Team: Catalan\n"
+ * "MIME-Version: 1.0\n"
+ * "Content-Type: text/plain; charset=utf-8\n"
+ * "Content-Transfer-Encoding: 8bit\n"
+ * "Plural-Forms: nplurals=2; plural=(n>1);\n"
+ */
+class PoHeader {
+
+  /**
+   * Language code.
+   *
+   * @var string
+   */
+  private $_langcode;
+
+  /**
+   * Formula for the plural form.
+   *
+   * @var string
+   */
+  private $_pluralForms;
+
+  /**
+   * Author(s) of the file.
+   *
+   * @var string
+   */
+  private $_authors;
+
+  /**
+   * Date the po file got created.
+   *
+   * @var string
+   */
+  private $_po_date;
+
+  /**
+   * Human readable language name.
+   *
+   * @var string
+   */
+  private $_languageName;
+
+  /**
+   * Name of the project the translation belongs to.
+   *
+   * @var string
+   */
+  private $_projectName;
+
+  /**
+   * Constructor, creates a PoHeader with default values.
+   *
+   * @param string $langcode
+   *   Language code.
+   */
+  public function __construct($langcode = NULL) {
+    $this->_langcode = $langcode;
+    // Ignore errors when run during site installation before
+    // date_default_timezone_set() is called.
+    $this->_po_date = @date("Y-m-d H:iO");
+    $this->_pluralForms = 'nplurals=2; plural=(n > 1);';
+  }
+
+  /**
+   * Gets the plural form.
+   *
+   * @return string
+   *   Plural form component from the header, for example:
+   *   'nplurals=2; plural=(n > 1);'.
+   */
+  public function getPluralForms() {
+    return $this->_pluralForms;
+  }
+
+  /**
+   * Set the human readable language name.
+   *
+   * @param string $languageName
+   *   Human readable language name.
+   */
+  public function setLanguageName($languageName) {
+    $this->_languageName = $languageName;
+  }
+
+  /**
+   * Gets the human readable language name.
+   *
+   * @return string
+   *   The human readable language name.
+   */
+  public function getLanguageName() {
+    return $this->_languageName;
+  }
+
+  /**
+   * Set the project name.
+   *
+   * @param string $projectName
+   *   Human readable project name.
+   */
+  public function setProjectName($projectName) {
+    $this->_projectName = $projectName;
+  }
+
+  /**
+   * Gets the project name.
+   *
+   * @return string
+   *   The human readable project name.
+   */
+  public function getProjectName() {
+    return $this->_projectName;
+  }
+
+  /**
+   * Populate internal values from a string.
+   *
+   * @param string $header
+   *   Full header string with key-value pairs.
+   */
+  public function setFromString($header) {
+    // Get an array of all header values for processing.
+    $values = $this->parseHeader($header);
+
+    // There is only one value relevant for our header implementation when
+    // reading, and that is the plural formula.
+    if (!empty($values['Plural-Forms'])) {
+      $this->_pluralForms = $values['Plural-Forms'];
+    }
+  }
+
+  /**
+   * Generate a Gettext PO formatted header string based on data set earlier.
+   */
+  public function __toString() {
+    $output = '';
+
+    $isTemplate = empty($this->_languageName);
+
+    $output .= '# ' . ($isTemplate ? 'LANGUAGE' : $this->_languageName) . ' translation of ' . ($isTemplate ? 'PROJECT' : $this->_projectName) . "\n";
+    if (!empty($this->_authors)) {
+      $output .= '# Generated by ' . implode("\n# ", $this->_authors) . "\n";
+    }
+    $output .= "#\n";
+
+    // Add the actual header information.
+    $output .= "msgid \"\"\n";
+    $output .= "msgstr \"\"\n";
+    $output .= "\"Project-Id-Version: PROJECT VERSION\\n\"\n";
+    $output .= "\"POT-Creation-Date: " . $this->_po_date . "\\n\"\n";
+    $output .= "\"PO-Revision-Date: " . $this->_po_date . "\\n\"\n";
+    $output .= "\"Last-Translator: NAME <EMAIL@ADDRESS>\\n\"\n";
+    $output .= "\"Language-Team: LANGUAGE <EMAIL@ADDRESS>\\n\"\n";
+    $output .= "\"MIME-Version: 1.0\\n\"\n";
+    $output .= "\"Content-Type: text/plain; charset=utf-8\\n\"\n";
+    $output .= "\"Content-Transfer-Encoding: 8bit\\n\"\n";
+    $output .= "\"Plural-Forms: " . $this->_pluralForms . "\\n\"\n";
+    $output .= "\n";
+
+    return $output;
+  }
+
+  /**
+   * Parses a Plural-Forms entry from a Gettext Portable Object file header.
+   *
+   * @param string $pluralforms
+   *   The Plural-Forms entry value.
+   *
+   * @return
+   *   An indexed array of parsed plural formula data. Containing:
+   *   - 'nplurals': The number of plural forms defined by the plural formula.
+   *   - 'plurals': Array of plural positions keyed by plural value.
+   *
+   * @throws Exception
+   */
+  public function parsePluralForms($pluralforms) {
+    $plurals = [];
+    // First, delete all whitespace.
+    $pluralforms = strtr($pluralforms, [" " => "", "\t" => ""]);
+
+    // Select the parts that define nplurals and plural.
+    $nplurals = strstr($pluralforms, "nplurals=");
+    if (strpos($nplurals, ";")) {
+      // We want the string from the 10th char, because "nplurals=" length is 9.
+      $nplurals = substr($nplurals, 9, strpos($nplurals, ";") - 9);
+    }
+    else {
+      return FALSE;
+    }
+    $plural = strstr($pluralforms, "plural=");
+    if (strpos($plural, ";")) {
+      // We want the string from the 8th char, because "plural=" length is 7.
+      $plural = substr($plural, 7, strpos($plural, ";") - 7);
+    }
+    else {
+      return FALSE;
+    }
+
+    // If the number of plurals is zero, we return a default result.
+    if ($nplurals == 0) {
+      return [$nplurals, ['default' => 0]];
+    }
+
+    // Calculate possible plural positions of different plural values. All known
+    // plural formula's are repetitive above 100.
+    // For data compression we store the last position the array value
+    // changes and store it as default.
+    $element_stack = $this->parseArithmetic($plural);
+    if ($element_stack !== FALSE) {
+      for ($i = 0; $i <= 199; $i++) {
+        $plurals[$i] = $this->evaluatePlural($element_stack, $i);
+      }
+      $default = $plurals[$i - 1];
+      $plurals = array_filter($plurals, function ($value) use ($default) {
+        return ($value != $default);
+      });
+      $plurals['default'] = $default;
+
+      return [$nplurals, $plurals];
+    }
+    else {
+      throw new \Exception('The plural formula could not be parsed.');
+    }
+  }
+
+  /**
+   * Parses a Gettext Portable Object file header.
+   *
+   * @param string $header
+   *   A string containing the complete header.
+   *
+   * @return array
+   *   An associative array of key-value pairs.
+   */
+  private function parseHeader($header) {
+    $header_parsed = [];
+    $lines = array_map('trim', explode("\n", $header));
+    foreach ($lines as $line) {
+      if ($line) {
+        list($tag, $contents) = explode(":", $line, 2);
+        $header_parsed[trim($tag)] = trim($contents);
+      }
+    }
+    return $header_parsed;
+  }
+
+  /**
+   * Parses and sanitizes an arithmetic formula into a plural element stack.
+   *
+   * While parsing, we ensure, that the operators have the right
+   * precedence and associativity.
+   *
+   * @param string $string
+   *   A string containing the arithmetic formula.
+   *
+   * @return
+   *   A stack of values and operations to be evaluated.
+   */
+  private function parseArithmetic($string) {
+    // Operator precedence table.
+    $precedence = ["(" => -1, ")" => -1, "?" => 1, ":" => 1, "||" => 3, "&&" => 4, "==" => 5, "!=" => 5, "<" => 6, ">" => 6, "<=" => 6, ">=" => 6, "+" => 7, "-" => 7, "*" => 8, "/" => 8, "%" => 8];
+    // Right associativity.
+    $right_associativity = ["?" => 1, ":" => 1];
+
+    $tokens = $this->tokenizeFormula($string);
+
+    // Parse by converting into infix notation then back into postfix
+    // Operator stack - holds math operators and symbols.
+    $operator_stack = [];
+    // Element Stack - holds data to be operated on.
+    $element_stack = [];
+
+    foreach ($tokens as $token) {
+      $current_token = $token;
+
+      // Numbers and the $n variable are simply pushed into $element_stack.
+      if (is_numeric($token)) {
+        $element_stack[] = $current_token;
+      }
+      elseif ($current_token == "n") {
+        $element_stack[] = '$n';
+      }
+      elseif ($current_token == "(") {
+        $operator_stack[] = $current_token;
+      }
+      elseif ($current_token == ")") {
+        $topop = array_pop($operator_stack);
+        while (isset($topop) && ($topop != "(")) {
+          $element_stack[] = $topop;
+          $topop = array_pop($operator_stack);
+        }
+      }
+      elseif (!empty($precedence[$current_token])) {
+        // If it's an operator, then pop from $operator_stack into
+        // $element_stack until the precedence in $operator_stack is less
+        // than current, then push into $operator_stack.
+        $topop = array_pop($operator_stack);
+        while (isset($topop) && ($precedence[$topop] >= $precedence[$current_token]) && !(($precedence[$topop] == $precedence[$current_token]) && !empty($right_associativity[$topop]) && !empty($right_associativity[$current_token]))) {
+          $element_stack[] = $topop;
+          $topop = array_pop($operator_stack);
+        }
+        if ($topop) {
+          // Return element to top.
+          $operator_stack[] = $topop;
+        }
+        // Parentheses are not needed.
+        $operator_stack[] = $current_token;
+      }
+      else {
+        return FALSE;
+      }
+    }
+
+    // Flush operator stack.
+    $topop = array_pop($operator_stack);
+    while ($topop != NULL) {
+      $element_stack[] = $topop;
+      $topop = array_pop($operator_stack);
+    }
+    $return = $element_stack;
+
+    // Now validate stack.
+    $previous_size = count($element_stack) + 1;
+    while (count($element_stack) < $previous_size) {
+      $previous_size = count($element_stack);
+      for ($i = 2; $i < count($element_stack); $i++) {
+        $op = $element_stack[$i];
+        if (!empty($precedence[$op])) {
+          if ($op == ":") {
+            $f = $element_stack[$i - 2] . "):" . $element_stack[$i - 1] . ")";
+          }
+          elseif ($op == "?") {
+            $f = "(" . $element_stack[$i - 2] . "?(" . $element_stack[$i - 1];
+          }
+          else {
+            $f = "(" . $element_stack[$i - 2] . $op . $element_stack[$i - 1] . ")";
+          }
+          array_splice($element_stack, $i - 2, 3, $f);
+          break;
+        }
+      }
+    }
+
+    // If only one element is left, the number of operators is appropriate.
+    return count($element_stack) == 1 ? $return : FALSE;
+  }
+
+  /**
+   * Tokenize the formula.
+   *
+   * @param string $formula
+   *   A string containing the arithmetic formula.
+   *
+   * @return array
+   *   List of arithmetic tokens identified in the formula.
+   */
+  private function tokenizeFormula($formula) {
+    $formula = str_replace(" ", "", $formula);
+    $tokens = [];
+    for ($i = 0; $i < strlen($formula); $i++) {
+      if (is_numeric($formula[$i])) {
+        $num = $formula[$i];
+        $j = $i + 1;
+        while ($j < strlen($formula) && is_numeric($formula[$j])) {
+          $num .= $formula[$j];
+          $j++;
+        }
+        $i = $j - 1;
+        $tokens[] = $num;
+      }
+      elseif ($pos = strpos(" =<>!&|", $formula[$i])) {
+        $next = $formula[$i + 1];
+        switch ($pos) {
+          case 1:
+          case 2:
+          case 3:
+          case 4:
+            if ($next == '=') {
+              $tokens[] = $formula[$i] . '=';
+              $i++;
+            }
+            else {
+              $tokens[] = $formula[$i];
+            }
+            break;
+          case 5:
+            if ($next == '&') {
+              $tokens[] = '&&';
+              $i++;
+            }
+            else {
+              $tokens[] = $formula[$i];
+            }
+            break;
+          case 6:
+            if ($next == '|') {
+              $tokens[] = '||';
+              $i++;
+            }
+            else {
+              $tokens[] = $formula[$i];
+            }
+            break;
+        }
+      }
+      else {
+        $tokens[] = $formula[$i];
+      }
+    }
+    return $tokens;
+  }
+
+  /**
+   * Evaluate the plural element stack using a plural value.
+   *
+   * Using an element stack, which represents a plural formula, we calculate
+   * which plural string should be used for a given plural value.
+   *
+   * An example of plural formula parting and evaluation:
+   *   Plural formula: 'n!=1'
+   * This formula is parsed by parseArithmetic() to a stack (array) of elements:
+   *   array(
+   *     0 => '$n',
+   *     1 => '1',
+   *     2 => '!=',
+   *   );
+   * The evaluatePlural() method evaluates the $element_stack using the plural
+   * value $n. Before the actual evaluation, the '$n' in the array is replaced
+   * by the value of $n.
+   *   For example: $n = 2 results in:
+   *   array(
+   *     0 => '2',
+   *     1 => '1',
+   *     2 => '!=',
+   *   );
+   * The stack is processed until only one element is (the result) is left. In
+   * every iteration the top elements of the stack, up until the first operator,
+   * are evaluated. After evaluation the arguments and the operator itself are
+   * removed and replaced by the evaluation result. This is typically 2
+   * arguments and 1 element for the operator.
+   *   Because the operator is '!=' the example stack is evaluated as:
+   *   $f = (int) 2 != 1;
+   *   The resulting stack is:
+   *   array(
+   *     0 => 1,
+   *   );
+   * With only one element left in the stack (the final result) the loop is
+   * terminated and the result is returned.
+   *
+   * @param array $element_stack
+   *   Array of plural formula values and operators create by parseArithmetic().
+   * @param int $n
+   *   The @count number for which we are determining the right plural position.
+   *
+   * @return int
+   *   Number of the plural string to be used for the given plural value.
+   *
+   * @see parseArithmetic()
+   * @throws Exception
+   */
+  protected function evaluatePlural($element_stack, $n) {
+    $count = count($element_stack);
+    $limit = $count;
+    // Replace the '$n' value in the formula by the plural value.
+    for ($i = 0; $i < $count; $i++) {
+      if ($element_stack[$i] === '$n') {
+        $element_stack[$i] = $n;
+      }
+    }
+
+    // We process the stack until only one element is (the result) is left.
+    // We limit the number of evaluation cycles to prevent an endless loop in
+    // case the stack contains an error.
+    while (isset($element_stack[1])) {
+      for ($i = 2; $i < $count; $i++) {
+        // There's no point in checking non-symbols. Also, switch(TRUE) would
+        // match any case and so it would break.
+        if (is_bool($element_stack[$i]) || is_numeric($element_stack[$i])) {
+          continue;
+        }
+        $f = NULL;
+        $length = 3;
+        $delta = 2;
+        switch ($element_stack[$i]) {
+          case '==':
+            $f = $element_stack[$i - 2] == $element_stack[$i - 1];
+            break;
+          case '!=':
+            $f = $element_stack[$i - 2] != $element_stack[$i - 1];
+            break;
+          case '<=':
+            $f = $element_stack[$i - 2] <= $element_stack[$i - 1];
+            break;
+          case '>=':
+            $f = $element_stack[$i - 2] >= $element_stack[$i - 1];
+            break;
+          case '<':
+            $f = $element_stack[$i - 2] < $element_stack[$i - 1];
+            break;
+          case '>':
+            $f = $element_stack[$i - 2] > $element_stack[$i - 1];
+            break;
+          case '+':
+            $f = $element_stack[$i - 2] + $element_stack[$i - 1];
+            break;
+          case '-':
+            $f = $element_stack[$i - 2] - $element_stack[$i - 1];
+            break;
+          case '*':
+            $f = $element_stack[$i - 2] * $element_stack[$i - 1];
+            break;
+          case '/':
+            $f = $element_stack[$i - 2] / $element_stack[$i - 1];
+            break;
+          case '%':
+            $f = $element_stack[$i - 2] % $element_stack[$i - 1];
+            break;
+          case '&&':
+            $f = $element_stack[$i - 2] && $element_stack[$i - 1];
+            break;
+          case '||':
+            $f = $element_stack[$i - 2] || $element_stack[$i - 1];
+            break;
+          case ':':
+            $f = $element_stack[$i - 3] ? $element_stack[$i - 2] : $element_stack[$i - 1];
+            // This operator has 3 preceding elements, instead of the default 2.
+            $length = 5;
+            $delta = 3;
+            break;
+        }
+
+        // If the element is an operator we remove the processed elements and
+        // store the result.
+        if (isset($f)) {
+          array_splice($element_stack, $i - $delta, $length, $f);
+          break;
+        }
+      }
+    }
+    if (!$limit) {
+      throw new \Exception('The plural formula could not be evaluated.');
+    }
+    return (int) $element_stack[0];
+  }
+
+}