Pdf.js and viewer.js. Pass a stream or blob to the viewer

If you've got an typed array (e.g. an Uint8Array), then the file can be opened using PDFView.open(typedarray, 0);.

If you've got a Blob or File object, then the data has to be converted to a typed array before you can view it:

var fr = new FileReader();
fr.onload = function() {
    var arraybuffer = this.result;
    var uint8array = new Uint8Array(arraybuffer);
    PDFView.open(uint8array, 0);
};   
fr.readAsArrayBuffer(blob);

Another method is to create a URL for the Blob/File object:

var url = URL.createObjectURL(blob);
PDFView.open(url, 0);

If the PDF Viewer is hosted at the same origin as your website that embeds the frame, then you can also view the PDF by passing the blob URL to the viewer:

var url = URL.createObjectURL(blob);
var viewerUrl = 'web/viewer.html?file=' + encodeURIComponent(url);
// TODO: Load the PDF.js viewer in a frame or new tab/window.

I'm using PDFJS.version = '1.0.1040'; PDFJS.build = '997096f';

The code that worked for me to get base64 pdf data loaded was this:

function (base64Data) {
  var pdfData = base64ToUint8Array(base64Data);
  PDFJS.getDocument(pdfData).then(function (pdf) {
    pdf.getPage(1).then(function (page) {
      var scale = 1;
      var viewport = page.getViewport(scale);
      var canvas = document.getElementById('myCanvas');
      var context = canvas.getContext('2d');
      canvas.height = viewport.height;
      canvas.width = viewport.width;
      page.render({ canvasContext: context, viewport: viewport });
    });
  });

  function base64ToUint8Array(base64) {
    var raw = atob(base64);
    var uint8Array = new Uint8Array(raw.length);
    for (var i = 0; i < raw.length; i++) {
      uint8Array[i] = raw.charCodeAt(i);
    }
    return uint8Array;
  }
}

This function could be the success function of an api call promise. What I'm doing here is rendering the pdf onto a canvas element myCanvas.

<canvas id="myCanvas"></canvas>

This shows the first page of the pdf but has no functionality. I can see why the viewer is desirable. If I get this hooked up to the viewer (viewer.html / viewer.js) I will edit my answer.

EDIT: How to hook up the viewer

1 In bower.json, add "pdfjs-viewer": "1.0.1040"

2 Html:

<iframe id="pdfViewer" src="lib/pdfjs-viewer/web/viewer.html" style="width: 100%; height: 700px;" allowfullscreen="" webkitallowfullscreen=""></iframe>

3 Change the stupid default document in the viewer.js file:

var DEFAULT_URL = '';

4 Controller:

var pdfjsframe = document.getElementById('pdfViewer');
pdfjsframe.onload = function() {
  LoadPdfDocument();
};

$scope.myApiCallThatReturnsBase64PdfData.then(
  function(base64Data) {
    $scope.base64Data = base64Data;
    LoadPdfDocument();
  },
  function(failure) {

    //NotificationService.error(failure.Message);

  });

function LoadPdfDocument() {
  if ($scope.PdfDocumentLoaded)
    return;
  if (!$scope.base64Data)
    return;

  var pdfData = base64ToUint8Array($scope.base64Data);
  pdfjsframe.contentWindow.PDFViewerApplication.open(pdfData);

  $scope.PdfDocumentLoaded = true;
}

function base64ToUint8Array(base64) {
  var raw = atob(base64);
  var uint8Array = new Uint8Array(raw.length);
  for (var i = 0; i < raw.length; i++) {
    uint8Array[i] = raw.charCodeAt(i);
  }
  return uint8Array;
}