Opening a document in WebViewer from base64 data

If you have the file data as a base64 string, the best way to load the document in WebViewer is to first convert it to a Blob and then load it as described for Blobs . Below is some example code showing how to convert base64 to a Blob.

function base64ToBlob(base64) {
  const binaryString = window.atob(base64);
  const len = binaryString.length;
  const bytes = new Uint8Array(len);
  for (let i = 0; i < len; ++i) {
    bytes[i] = binaryString.charCodeAt(i);
  }

  return new Blob([bytes], { type: 'application/pdf' });
};

WebViewer(...)
  .then(instance => {
    // `myBase64String` is your base64 data which can come
    // from sources such as a server or the filesystem
    instance.UI.loadDocument(base64ToBlob(myBase64String), { filename: 'myfile.pdf' });

    const { documentViewer } = instance.Core;
    documentViewer.addEventListener('documentLoaded', () => {
      // perform document operations
    });
  });

See more WebViewer events such as documentLoaded to understand when to execute API operations.

WebViewer provides various options to load a document. Whether you are loading a document through the initialDoc option in the constructor or calling loadDocument after mounting, you can always provide options to load your document.

When loading a document using a URL, WebViewer will use the URL to determine what type of file it is. For example http://myserver.com/myfile.docx ends with .docx so WebViewer will assume it's a docx file. However, what happens if you are loading from a blob or extensionless URL? That's where the extension option comes in.

You can use the extension option to explicitly tell WebViewer what type of file it is. For example, extension: 'docx' or extension: 'png'. By default WebViewer will assume it's a PDF file but that might not be correct.

WebViewer({
  path: '../../../lib',
  initialDoc: 'http://<documentserver>/FileDownload?docId=foo',
  extension: 'docx',
  ...
}, document.getElementById('viewer'))
  .then(instance => {
    // ...
  });

The filename option is used to indicate the name of the file when you press the download button in the viewer. However, the option can also be used as a way of indicating the type of file you are opening when the URL does not end with a file extension. Note that the extension property has precedence over filename for determining the document type.

WebViewer({
  path: '../../../lib',
  initialDoc: 'http://<documentserver>/FileDownload?docId=foo',
  filename: 'report.docx',
  ...
}, document.getElementById('viewer'))
  .then(instance => {
    // ...
  });

If your document server requires additional options in the HTTP request, you can use the second argument in loadDocument function to pass them. This is especially useful when you need the Authorization header in the request with your auth key.

WebViewer(...)
  .then(instance => {
    instance.UI.loadDocument('https://myserver.com/myfile.pdf', {
      customHeaders: {
        Authorization: 'Basic YWxhZGRpbjpvcGVuc2VzYW1l'
      }
    });
  });

For password-protected documents, it can be provided during the loadDocument call via the options argument. It can either take the password string or a function that will eventually provide a password via a callback provided as a parameter.

WebViewer(...)
  .then(instance => {
    instance.UI.loadDocument('https://myserver.com/myfile.pdf', {
      password: 'asdf'
    });
  });

A PDFTron custom security handler easily encrypts and secures documents with our algorithm to allow opening the document only in WebViewer (or PDFNet).

For these types of documents, it is necessary to provide the integer custom handler ID along with the password.

WebViewer(...)
  .then(instance => {
    instance.UI.loadDocument('https://myserver.com/myfile.pdf', {
      password: 'asdf',
      customHandlerId: 42
    });
  });

If you run into any issues loading a document, please visit our FAQ.