Trying to merge pdf files in node: PDFUnite + Nodejs - node.js

Question

I have a site on heroku, and am using the HyPDF addon which allows you to manipulate pdf's in a number ways. Specifically, I am trying to merge two pdf's that I have the URL's for.
However, it's not working. I am using request to pull the pdf files and then using request to make the call to PDFUnite. It's a bit of callback hell too, so if you have any suggestions on how to fix that, I would really appreciate it!
Thanks!
request({url: 'http://www.sesamestreet.org/cms_services/services?action=download&uid=4010e80d-9106-4824-95ab-799ec81c7fd0', encoding: null}, function(err, res, body) {
var pdf1 = body;
request({url: 'http://www.sesamestreet.org/cms_services/services?action=download&uid=28a388c6-ca0e-45a1-9aaf-9b6688c5a557', encoding: null}, function(err2, res2, body2){
var pdf2 = body2;
request.post(
'https://www.hypdf.com/htmltopdf',
{
json: {
user: HY_USER,
password: HY_PASS,
file_1: pdf1,
file_2: pdf2
}
},
function (error3, res3, body3) {
if (!error && res2.statusCode == 200) {
console.log('Public URL: ', body3.url);
console.log('Number of pages: ', res3.headers['hypdf-pages']);
}
});
})
});
/****************UDPATED*****************/
I've updated the code, using https://gist.github.com/redfield/6724717 as a guide. The difference is that code sample uses files, whereas I'm using a URL.
I've tried to modify it appropriately, but obviously something is off...If I use body or body.toString('base64') as the pdf1 and pdf2 then I get a 400 status error. Otherwise, if I use the res as the pdf files, then I get a 504 error. I'm not really sure how I should be sending in the files, so it's just guess and check. Appreciate the help!
request({url: 'http://www.sesamestreet.org/cms_services/services?action=download&uid=4010e80d-9106-4824-95ab-799ec81c7fd0', encoding: null}, function(err, res, body) {
var pdf1 = body;
request({url: 'http://www.sesamestreet.org/cms_services/services?action=download&uid=28a388c6-ca0e-45a1-9aaf-9b6688c5a557', encoding: null}, function(err2, res2, body2){
var pdf2 = body2;
var form = new FormData();
form.append('user', HYPDF_USER);
form.append('password', HYPDF_PASSWORD);
form.append('test', 'true');
// form.append('bucket', 'hypdf_test');
form.append('key', 'hypdf_test.pdf');
form.append('public', 'true');
form.append('file1', pdf1);
form.append('file2', pdf2);
form.submit('https://www.hypdf.com/pdfunite', function(err, res) {
console.log('err ', err);
// res – response object (http.IncomingMessage)
console.log(res.statusCode, res.resume());
});
})
});
UPDATE #2
I've updated the code combining my code with #remus' code below. However, I'm still getting an error - "Cannot call method 'hasOwnProperty' of null" on the request.post line. Any thoughts?
request({url: 'http://www.sesamestreet.org/cms_services/services?action=download&uid=4010e80d-9106-4824-95ab-799ec81c7fd0', encoding: null}, function(err, res, body) {
var pdf1 = body.toString('base64');
request({url: 'http://www.sesamestreet.org/cms_services/services?action=download&uid=28a388c6-ca0e-45a1-9aaf-9b6688c5a557', encoding: null}, function(err2, res2, body2){
var pdf2 = body2.toString('base64');
var form = new FormData();
form.append('user', HY_UN);
form.append('password', HY_PASS);
form.append('public', 'true');
form.append('file1', fs.createReadStream(pdf1));
form.append('file2', fs.createReadStream(pdf1));
request.post({
url: 'https://www.hypdf.com/pdfunite',
formData: form
}, function(e, r, body) {
// body should be the binary result of the merged .pdf
console.log('e', e);
console.log('body', body);
});
})
});
UPDATE 3
ERROR STACK for the request.post - I've tried a number of things, can't get rid of it. Any thoughts?
TypeError: Cannot call method 'hasOwnProperty' of null
at appendFormValue (/node_modules/request/request.js:340:17)
at Request.init (/node_modules/request/request.js:354:11)
at new Request (/node_modules/request/request.js:140:8)
at request (/node_modules/request/index.js:55:10)
at Function.post (/node_modules/request/index.js:63:12)
**at Request._callback (/server/api/emailInvoice/emailInvoice.controller.js:34:12)**
at Request.self.callback (/node_modules/request/request.js:198:22)
at Request.emit (events.js:98:17)
at Request.<anonymous> (/node_modules/request/request.js:1073:14)
at Request.emit (events.js:117:20)
at IncomingMessage.<anonymous> (/node_modules/request/request.js:1019:12)
at IncomingMessage.emit (events.js:117:20)
at _stream_readable.js:929:16
at process._tickCallback (node.js:419:13)

Answer 1

First off, the main problem is you're trying to POST binary data (.pdf) as JSON in your last POST request. I imagine that's not going to work - like maybe it expects multipart file data? Second, an easy way to fix up your callback hell is to use node-async:
var request = require('request');
var async = require('async');
async.parallel(function(callback) {
pdf1: function(callback) {
request.get({
url: 'http://www.sesamestreet.org/cms_services/services?action=download&uid=4010e80d-9106-4824-95ab-799ec81c7fd0'
}, function(err, r, body) {
callback(err, body);
});
},
pdf2: function(callback) {
request.get({
url: 'http://www.sesamestreet.org/cms_services/services?action=download&uid=28a388c6-ca0e-45a1-9aaf-9b6688c5a557'
}, function(err, r, body) {
callback(err, body);
});
},
function(err, results) {
var formData = {
user: HY_USER,
password: HY_PASS,
file_1: fs.createReadStream(results.pdf1),
file_2: fs.createReadStream(results.pdf2)
}
request.post({
url: 'https://www.hypdf.com/pdfunite',
formData: formData
}, function(e, r, body) {
// body should be the binary result of the merged .pdf
});
});
});
Notice both the fs.createReadStream from the binary data stream, and the proper url using pdfunite.
You might also want to check out the hypdf NPM module - I didn't test it out, but it might make things even easier than manually building up the request.
****UPDATE****
The problem was with using FormData(). For some reason, request.post didn't like it. I was also able to remove the callbacks by injecting the request streams directly into the form. Also note, you have to set encoding to null.
var finalpdf;
var formData = {
'user': HY_USER,
'password': HY_PASSWORD,
'test': 'true',
'public': 'true',
'file1': request({url: 'http://www.sesamestreet.org/cms_services/services?action=download&uid=4010e80d-9106-4824-95ab-799ec81c7fd0', encoding: null}),
'file2': request({url: 'http://www.sesamestreet.org/cms_services/services?action=download&uid=28a388c6-ca0e-45a1-9aaf-9b6688c5a557', encoding: null})
}
request.post({url: 'https://www.hypdf.com/pdfunite', encoding: null, formData: formData}, function(err, res3, body3){
finalPdf = body3.toString('base64');
});