Serving PDF content back to browser via Node Express using pdfMake - angularjs

Question

I am making use of the pdfmake library for generating PDF documents in my node express application and want these to be sent straight back to the client to trigger the browser to automatically download the file.
As a reference point I have been using the following examples for my express middleware:
https://gist.github.com/w33ble/38c5e0220d491148de1c
https://github.com/bpampuch/pdfmake/issues/489
I have opted for sending a buffered response back, so the key part of my middleware looks like this:
function createPDFDocument(docDefinition, callback) {
var fontDescriptors = {
Roboto: {
normal: './src/server/fonts/Roboto-Regular.ttf',
bold: './src/server/fonts/Roboto-Medium.ttf',
italics: './src/server/fonts/Roboto-Italic.ttf',
bolditalics: './src/server/fonts/Roboto-MediumItalic.ttf'
}
};
var printer = new Printer(fontDescriptors);
var pdfDoc = printer.createPdfKitDocument(docDefinition);
// buffer the output
var chunks = [];
pdfDoc.on('data', function(chunk) {
chunks.push(chunk);
});
pdfDoc.on('end', function() {
var result = Buffer.concat(chunks);
callback(result);
});
pdfDoc.on('error', callback);
// close the stream
pdfDoc.end();
}
In my angular application I am using the $resource service and have an endpoint defined like so:
this.resource = $resource('api/document-requests/',
null,
<any>{
'save': {
method: 'POST',
responseType: 'arraybuffer'
}
});
When I try this out, I dont get any browser download kicking in, the response I receive is as follows when looking in Chrome:
And the response headers are as follows:
So it seems I'm not a million miles off, I have searched around and found solutions mentioning about converting to Blob, but I think that's only relevant if I were serving back a Base64 encoded string of the document.
Can anyone suggest what may be my issue here?
Thanks

Answer 1

Here's a router:
router.get('/get-pdf-doc', async (req, res, next)=>{ try {
var binaryResult = await createPdf();
res.contentType('application/pdf').send(binaryResult);
} catch(err){
saveError(err);
res.send('<h2>There was an error displaying the PDF document.
'</h2>Error message: ' + err.message);
}});
And here's a function to return the pdf.
const PdfPrinter = require('pdfmake');
const Promise = require("bluebird");
createPdf = async ()=>{
var fonts = {
Helvetica: {
normal: 'Helvetica',
bold: 'Helvetica-Bold',
italics: 'Helvetica-Oblique',
bolditalics: 'Helvetica-BoldOblique'
};
var printer = new PdfPrinter(fonts);
var docDefinition = {
content: [
'First paragraph',
'Another paragraph, this time a little bit longer to make sure,'+
' this line will be divided into at least two lines'
],
defaultStyle: {
font: 'Helvetica'
}
};
var pdfDoc = printer.createPdfKitDocument(docDefinition);
return new Promise((resolve, reject) =>{ try {
var chunks = [];
pdfDoc.on('data', chunk => chunks.push(chunk));
pdfDoc.on('end', () => resolve(Buffer.concat(chunks)));
pdfDoc.end();
} catch(err) {
reject(err);
}});
};

Answer 2

Everything seems fine to me, the only thing missing is the logic to trigger the download.
Check out this CodePen as an example.
Here I'm using base64 encoded data, but you can just use binary data as well, just don't forget to change the href, where I'm mentioning scope.dataURL = base64....

Answer 3

I had issue serving PDF files from Node.js as well, so I made use of phantomjs. You can checkout this repository for full codebase and implementation.
console.log('Loading web page')
const page = require('webpage').create()
const args = require('system').args
const url = 'www.google.com'
page.viewportSize = { width: 1024, height: 768 }
page.clipRect = { top: 0, left: 0 }
page.open(url, function(status) {
console.log('Page loaded')
setTimeout(function() {
page.render('docs/' + args[1] + '.pdf')
console.log('Page rendered')
phantom.exit()
}, 10000)
})