title: Multiple data uri pdf files into 1 file javascript
body: <p>I have a working file system to save PDF files.  At the end of the job, I want to be able to take all these PDF files and combine them into 1 file (one page after another).  When I download the file off of the file system, I get the data uri.  I can call window.open(data uri) and it will open the pdf.  I have tried to take 2 data uri strings and simply combine them but it doesn't open anything.  </p>
  
  <pre><code>data:application/pdf;base64,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...
  </code></pre>
  
  <p>How can I combine these data strings to get one page after another?  </p>