Convert PDF to PDF/A formats

Aspose.PDF for JavaScript allows you to convert a PDF file to a PDF/A compliant PDF file.

Converting operation depends on the number of pages in the document and can be very time-consuming. Therefore, we highly recommend using Web Workers.

This code demonstrates a way to offload resource-intensive PDF file converting tasks to a web worker to prevent blocking the main UI thread. It also offers a user-friendly way to download the converted file.

Try to convert PDF to PDF/A online

Aspose.PDF for JavaScript presents you online free application “PDF to PDF/A-1A”, where you may try to investigate the functionality and quality it works.

Convert PDF to PDF/A format

  /*Create Web Worker*/
    const AsposePDFWebWorker = new Worker("AsposePDFforJS.js");
    AsposePDFWebWorker.onerror = evt => console.log(`Error from Web Worker: ${evt.message}`);
    AsposePDFWebWorker.onmessage = evt => document.getElementById('output').textContent = 
      (evt.data == 'ready') ? 'loaded!' :
        (evt.data.json.errorCode == 0) ? `Result:\n${DownloadFile(evt.data.json.fileNameResult, "application/pdf", evt.data.params[0])}\n${DownloadFile(evt.data.json.fileNameLogResult, "application/xml", evt.data.params[1])}` : `Error: ${evt.data.json.errorText}`;

    /*Event handler*/
    const ffilePdfConvertToPDFA = e => {
      const file_reader = new FileReader();
      file_reader.onload = event => {
        const pdfFormat = 'Module.PdfFormat.PDF_A_1A';
        /*convert a PDF-file to PDF/A(1A) and save the "ResultConvertToPDFA.pdf"*/
        /*during conversion process, the validation is also performed, "ResultConvertToPDFA.xml"- Ask Web Worker*/
        AsposePDFWebWorker.postMessage({ "operation": 'AsposePdfConvertToPDFA', "params": [event.target.result, e.target.files[0].name, pdfFormat, "ResultConvertToPDFA.pdf", "ResultConvertToPDFA.xml"] }, [event.target.result]);
      };
      file_reader.readAsArrayBuffer(e.target.files[0]);
    };
  /// [Code snippet]

    /*make a link to download the result file*/
    const DownloadFile = (filename, mime, content) => {
        mime = mime || "application/octet-stream";
        var link = document.createElement("a"); 
        link.href = URL.createObjectURL(new Blob([content], {type: mime}));
        link.download = filename;
        link.innerHTML = "Click here to download the file " + filename;
        document.body.appendChild(link); 
        document.body.appendChild(document.createElement("br"));
        return filename;
      }

The following JavaScript code snippet shows simple example of coverting PDF to PDF/A files:

1. Select a PDF file for converting.
2. Create a ‘FileReader’.
3. The AsposePdfConvertToPDFA function is executed.
4. The name of the resulting file is set, in this example “ResultConvertToPDFA.pdf”. During conversion process, the validation is also performed, “ResultConvertToPDFA.xml”.
5. Next, if the ‘json.errorCode’ is 0, then your DownloadFile is given the name you specified earlier. If the ‘json.errorCode’ parameter is not equal to 0 and, accordingly, there will be an error in your file, then information about such an error will be contained in the ‘json.errorText’ file.
6. As a result, the DownloadFile function generates a link and allows you to download the resulting file, and link to download the Log (xml) file to the user’s operating system.

  var ffilePdfConvertToPDFA = function (e) {
    const file_reader = new FileReader();
    file_reader.onload = (event) => {
      /*convert a PDF-file to PDF/A(1A) and save the "ResultConvertToPDFA.pdf"*/
      /*during conversion process, the validation is also performed, "ResultConvertToPDFA.xml"*/
      const json = AsposePdfConvertToPDFA(event.target.result, e.target.files[0].name, Module.PdfFormat.PDF_A_1A, "ResultConvertToPDFA.pdf", "ResultConvertToPDFA.xml");
      if (json.errorCode == 0)
      {
        document.getElementById('output').textContent = json.fileNameResult + "\nLog file (xml format): " + json.fileNameLogResult;
        /*make a link to download the result file*/
        DownloadFile(json.fileNameResult, "application/pdf");
      }
      else document.getElementById('output').textContent = json.errorText + "\nLog file (xml format): " + json.fileNameLogResult;
      /*make a link to download the Log (xml)*/
      DownloadFile(json.fileNameLogResult, "application/xml");
    };
    file_reader.readAsArrayBuffer(e.target.files[0]);
  };