angular-pdfjs-viewer - Message: stream must have data - angularjs

Question

I am struggling to get angular-pdfjs-viewer working in my angular app that's written in Typescript.
I am always getting a red error message with the text:
PDF.js v1.7.354 (build: 0f7548ba)
Message: stream must have data
The PDF data is coming from an ASP.NET WebAPI controller, and the architecture of our application has the front facing website and the API both deployed as two independent web applications.
Due to this, I am wanting to download the PDF in the angular controller, and set the PDF source to the data attribute of the directive.
The WebAPI returns the PDF like this:
[HttpGet]
[Route("invoice/{id}/originalpdf")]
public async Task<ActionResult> GetInvoiceSourceImagePdf(string id)
{
var userId = User.Identity.GetMyId();
var bytes = await _serviceThatReturnsByteArray(id);
return File(bytes, System.Net.Mime.MediaTypeNames.Application.Pdf);
}
I don't see an issue with the above. In the browser, if I hit this endpoint, I get the document rendering exactly as expected.
On the front-end side:
We're using the angular-pdfjs-viewer from https://github.com/legalthings/angular-pdfjs-viewer
We're including (via BundleConfig), sources in the order of: pdf.js, then angular.js and then finally angular-pdfjs-viewer.js (with other application required dependencies in between)
I am using the PDF.js dependency that "ships" with angular-pdfjs-viewer.js
The angular controller looks like this:
module MyApp {
class PdfDialogController {
public static $inject = ["$scope", "$window", "$log", "$uibModalInstance", "$http"];
pdfData: Uint8Array;
constructor(/*stuff*/){
this.$http.get(the_url, { responseType: 'arrayBuffer' })
.then((t) => {
this.pdfData = new Uint8Array(<ArrayBuffer>t.data);
});
}
}
}
And in the view, we have:
<div class="modal-body">
<div id="pdf-container">
<pdfjs-viewer data="vm.pdfData"></pdfjs-viewer>
</div>
</div>
Inspecting the network in the browser, the PDF content is downloaded.
t.data in the controller contains data that starts with
%PDF-1.3\n%����\n1 0 obj\n[/PDF /Text]
However, the views shows this:
And the console outputs an error message:
Error: An error occurred while loading the PDF.
What am I doing wrong, and how can I determine what the issue is with the PDF data (if there is one).

Answer 1

Well, it turns out that I was using
{ responseType: 'arrayBuffer' } // camel case
when I should be using
{ responseType: 'arraybuffer' } // all lowercase
Once changed, the code I posted in the question worked perfectly.