Uploading a PDF File From Swift Yields a Blank PDF - swift

Question

Im trying to upload a PDF generated from a UIImage. I take a picture using my camera framework, uploads all ok but the PDF on S3 is blank. Below is the code I am using:
I use the following class to create the PDF from a UIImage, tested ok.
// Using PDFKit
func generatePDF(source: UIImage) -> PDFDocument {
let pdfDocument = PDFDocument()
let pdfPage = PDFPage(image: source)
pdfDocument.insert(pdfPage!, at: 0)
return pdfDocument
}
I used Alamofire to perform a multipart upload with the pdf, tested ok.
class NetworkManager {
static let shared = NetworkManager()
func upload(document: Data, name: String) {
let filename = "\(name).pdf"
let urlString = endpoint + "?filename=" + filename
let url = URL(string: urlString)!
var request = URLRequest(url: url, cachePolicy: .useProtocolCachePolicy, timeoutInterval: 30)
request.method = .post
request.setValue(key, forHTTPHeaderField: api)
AF.upload(multipartFormData: { multiPart in
multiPart.append(document, withName: name, fileName: filename, mimeType: "application/pdf")
}, with: request)
.uploadProgress(queue: .main, closure: { progress in
print("Upload Progress: \(progress.fractionCompleted)")
})
.responseJSON(completionHandler: { data in
print("data: \(data)")
})
}
}
On AWS I am using the following framework to reconstruct the multipart data back to a PDF
lambda-multipart-parser
https://www.npmjs.com/package/lambda-multipart-parser
How Im using it in Lambda:
let filename = event.queryStringParameters.filename;
let documentData = await imageParser.parse(event);
let document = documentData.files[0];
var data = {
Bucket: 'order-scanned-copy',
Key: filename,
Body: document.content,
ContentType: "application/pdf",
};
let uploadFile = await s3.putObject(data).promise();
No errors, no warnings just a blank PDF. I can tell by the size around 500kb-1mb that it has something in it. Any help would be appreciated.
Thanks.

Answer 1

I figured it out, since I am using AWS specifically API Gateway and Lambda I needed to add the "Binary Media Type" to API Gateway. To do this I opened Api Gateway console and choose my API. Then, selected Settings and added the following types.
I did a redeploy of my api and everything worked perfect, so in the end it was not a code problem but configuration mistake on AWS.
This blog post was very helpful:
AWS SAM Configuration for API Gateway Binary Response / Payloads
Thanks for your help everyone.