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   1  <?php
   2  
   3  namespace Box\Spout\Writer\XLSX\Helper;
   4  
   5  use Box\Spout\Common\Exception\IOException;
   6  
   7  /**
   8   * Class SharedStringsHelper
   9   * This class provides helper functions to write shared strings
  10   *
  11   * @package Box\Spout\Writer\XLSX\Helper
  12   */
  13  class SharedStringsHelper
  14  {
  15      const SHARED_STRINGS_FILE_NAME = 'sharedStrings.xml';
  16  
  17      const SHARED_STRINGS_XML_FILE_FIRST_PART_HEADER = <<<EOD
  18  <?xml version="1.0" encoding="UTF-8" standalone="yes"?>
  19  <sst xmlns="http://schemas.openxmlformats.org/spreadsheetml/2006/main"
  20  EOD;
  21  
  22      /**
  23       * This number must be really big so that the no generated file will have more strings than that.
  24       * If the strings number goes above, characters will be overwritten in an unwanted way and will corrupt the file.
  25       */
  26      const DEFAULT_STRINGS_COUNT_PART = 'count="9999999999999" uniqueCount="9999999999999"';
  27  
  28      /** @var resource Pointer to the sharedStrings.xml file */
  29      protected $sharedStringsFilePointer;
  30  
  31      /** @var int Number of shared strings already written */
  32      protected $numSharedStrings = 0;
  33  
  34      /** @var \Box\Spout\Common\Escaper\XLSX Strings escaper */
  35      protected $stringsEscaper;
  36  
  37      /**
  38       * @param string $xlFolder Path to the "xl" folder
  39       */
  40      public function __construct($xlFolder)
  41      {
  42          $sharedStringsFilePath = $xlFolder . '/' . self::SHARED_STRINGS_FILE_NAME;
  43          $this->sharedStringsFilePointer = fopen($sharedStringsFilePath, 'w');
  44  
  45          $this->throwIfSharedStringsFilePointerIsNotAvailable();
  46  
  47          // the headers is split into different parts so that we can fseek and put in the correct count and uniqueCount later
  48          $header = self::SHARED_STRINGS_XML_FILE_FIRST_PART_HEADER . ' ' . self::DEFAULT_STRINGS_COUNT_PART . '>';
  49          fwrite($this->sharedStringsFilePointer, $header);
  50  
  51          /** @noinspection PhpUnnecessaryFullyQualifiedNameInspection */
  52          $this->stringsEscaper = new \Box\Spout\Common\Escaper\XLSX();
  53      }
  54  
  55      /**
  56       * Checks if the book has been created. Throws an exception if not created yet.
  57       *
  58       * @return void
  59       * @throws \Box\Spout\Common\Exception\IOException If the sheet data file cannot be opened for writing
  60       */
  61      protected function throwIfSharedStringsFilePointerIsNotAvailable()
  62      {
  63          if (!$this->sharedStringsFilePointer) {
  64              throw new IOException('Unable to open shared strings file for writing.');
  65          }
  66      }
  67  
  68      /**
  69       * Writes the given string into the sharedStrings.xml file.
  70       * Starting and ending whitespaces are preserved.
  71       *
  72       * @param string $string
  73       * @return int ID of the written shared string
  74       */
  75      public function writeString($string)
  76      {
  77          fwrite($this->sharedStringsFilePointer, '<si><t xml:space="preserve">' . $this->stringsEscaper->escape($string) . '</t></si>');
  78          $this->numSharedStrings++;
  79  
  80          // Shared string ID is zero-based
  81          return ($this->numSharedStrings - 1);
  82      }
  83  
  84      /**
  85       * Finishes writing the data in the sharedStrings.xml file and closes the file.
  86       *
  87       * @return void
  88       */
  89      public function close()
  90      {
  91          fwrite($this->sharedStringsFilePointer, '</sst>');
  92  
  93          // Replace the default strings count with the actual number of shared strings in the file header
  94          $firstPartHeaderLength = strlen(self::SHARED_STRINGS_XML_FILE_FIRST_PART_HEADER);
  95          $defaultStringsCountPartLength = strlen(self::DEFAULT_STRINGS_COUNT_PART);
  96  
  97          // Adding 1 to take into account the space between the last xml attribute and "count"
  98          fseek($this->sharedStringsFilePointer, $firstPartHeaderLength + 1);
  99          fwrite($this->sharedStringsFilePointer, sprintf("%-{$defaultStringsCountPartLength}s", 'count="' . $this->numSharedStrings . '" uniqueCount="' . $this->numSharedStrings . '"'));
 100  
 101          fclose($this->sharedStringsFilePointer);
 102      }
 103  }