title: save php spreadsheet template as PDF using Mpdf
body: <p>i need some help with phpspreadsheet, i'm trying to load an excel spreadsheet, add something to it and then save it as a pdf, the problem is that when i   load a template , saving as pdf doesn't work </p>
  
  <p>ps : when i create a new spreadsheet it works fine.</p>
  
  <pre><code> $reader = IOFactory::createReader('Xlsx');
  
   $spreadsheet = $reader-&gt;load('docs/MODEL_FACTURE_DOM_CRE.xlsx'); 
   $spreadsheet-&gt;setActiveSheetIndex(0)
          -&gt;setCellValue('B13', 'test')
          -&gt;setCellValue('F13', 'test');                            
   $spreadsheet-&gt;setActiveSheetIndex(0);
   $spreadsheet-&gt;getActiveSheet()-&gt;setShowGridLines(false);
  
   $rendererName = Settings::PDF_RENDERER_MPDF;
  
   Settings::setPdfRendererName($rendererName);
  
   $writer = IOFactory::createWriter($spreadsheet, 'Pdf');
  
   $filename = 'FACTURE.pdf';
  
   $writer-&gt;save($filename);
  </code></pre>
  
  <p>Any suggestions ? </p>