We Keep Coding

download a PDF with Javascript/Node.Js after generating data and storing the file into a path

I created a generator for PDF files that creates the file and sends to a specific path automatically after creation. Still I want to download it right after but didn't know how to do that. Any help would be appreciated. This is my generatorPdf.js :
module.exports={
pdfGenerator:function(data,pathfile){
var fonts = {
Roboto: {
normal: 'server/pdfgenerator/fonts/Roboto-Regular.ttf',
bold: 'server/pdfgenerator/fonts/Roboto-Medium.ttf',
italics: 'server/pdfgenerator/fonts/Roboto-Italic.ttf',
bolditalics: 'server/pdfgenerator/fonts/Roboto-MediumItalic.ttf'
}
};
var datePaiements='';
var dateFinPaiements='';
if(data.abonnement[0].datePaiement!=null)
datePaiements= new Date( data.abonnement[0].datePaiement.toString());
if(datePaiements!=='')
{
dateFinPaiements= ('0'+datePaiements.getDate()).slice(-2).toString()+'/'+('0'+(datePaiements.getMonth()+1)).slice(-2).toString()+'/'+(datePaiements.getFullYear()+1).toString();
datePaiements=('0'+datePaiements.getDate()).slice(-2).toString()+'/'+('0'+(datePaiements.getMonth()+1)).slice(-2).toString()+'/'+datePaiements.getFullYear().toString();
}
var dateFacture= new Date(data.abonnement[0].timestampCreation.toString());
dateFacture= ('0'+dateFacture.getDate()).slice(-2).toString()+'/'+('0'+(dateFacture.getMonth()+1)).slice(-2).toString()+'/'+dateFacture.getFullYear().toString();
var PdfPrinter = require('pdfmake/src/printer');
var printer = new PdfPrinter(fonts);
var fs = require('fs');
var dd = {
content: [ ..............],
footer:{.............}
}
try{
var pdfDoc = printer.createPdfKitDocument(dd);
if (fs.existsSync(pathfile)) {//server/pdfgenerator/documentpdf/basics21.pdf
fs.unlink(pathfile, (err) => {//server/pdfgenerator/documentpdf/basics21.pdf
if (err) {
console.error(err)
return
}
})
}
pdfDoc.pipe(fs.createWriteStream(pathfile)).on('finish',function(){//server/pdfgenerator/documentpdf/basics21.pdf
});
}
catch(e){
console.log(e);
return null;
}
}
}
and this is my remote method in Loopback to send the pdf to a path and where probably I have to do the download of the file:
cm_abonnements.getAbonnementById= async (options,req,res)=>{
const token = options && options.accessToken;
const userId = token && token.userId;
try{
if(userId!==null){
let dataComedien= await app.models.cm_comediens.getComedienByUser(userId);
let argAbn={};
const form = new formidable.IncomingForm();
var formPromise = await new Promise(function(resolve,reject){
form.parse(req,function(err,fields,files){
if(err)
{
reject(err);
return-1
}
console.log(fields.key)
argAbn.idAbonnement=fields.key;
resolve();
})
})
let dataFac=await cm_abonnements.find({where :{and :[{idAbonnement:argAbn.idAbonnement},{idComedien : dataComedien.idComedien}]}});
var data={abonnement:[]};
data.abonnement=dataFac;
var str_date= new Date(dataFac[0].timestampCreation.toString());
var nameFile= 'Fac_'+dataFac[0].idFacture+'_'+str_date.getFullYear().toString()+'-'+('0'+str_date.getMonth()+1).slice(-2).toString()+'-'+('0'+str_date.getDate()).slice(-2).toString()+'.pdf';
var path='public/upload/Comediens/'+dataComedien.idComedien.toString()+'/factures/'+nameFile;
createPdf.pdfGenerator(data,path);
return dataFac;
}
return null;
}
catch(e){
console.log(e);
return null;
}
}
cm_abonnements.remoteMethod(
'getAbonnementById',{
http:{
verb:'POST'
},
description:'Get detail facture by number facture',
accepts:[
{arg:"options", "type":"object","http":"optionsFromRequest"},
{ arg: 'req', type: 'object', 'http': {source: 'req'}},
{arg: 'res', type: 'object', 'http': {source: 'res'}}
],
returns:{arg:'data',root:true}
}
);
Any help would be appreciated. Thank you

You need to send the following HTTP headers:
Content-Type: application/pdf
Content-Disposition: inline; filename="download.pdf"

After data is generated and pdf file is stored, there are 2 steps left to implement the "download" feature:
Return HTTP response to browser, with Content-Type header as application/pdf, and Content-Disposition header as attachment; filename="yourname.pdf". Normally, this would be handled automatically by web framework. I'm not familiar with loopback, so take Express for example:
In generatorPdf.js, add a callback to listen the finish event:
pdfGenerator:function(data, pathfile, callback){
...
pdfDoc.pipe(fs.createWriteStream(pathfile)).on('finish', callback);
...
}
When pdfGenerator function is used, pass a callback function parameter. If the pdf work is "finished", return response to browser using res.download() (It's Express API, but I believe loopback has similar API as loopback is built on top of Express):
var nameFile=...
var path=...
createPdf.pdfGenerator(data, path, function() {
res.download(path, nameFile);
});
In browser side, if it's an AJAX request (I guess so, as you mentioned it is a POST request), you need to handle the request with some blob operation. Here is an example snippet, with explanation comment:
var req = new XMLHttpRequest();
req.open('POST', '/download', true); // Open an async AJAX request.
req.setRequestHeader('Content-Type', 'application/json'); // Send JSON data
req.responseType = 'blob'; // Define the expected data as blob
req.onreadystatechange = function () {
if (req.readyState === 4) {
if (req.status === 200) { // When data is received successfully
var data = req.response;
var defaultFilename = 'default.pdf';
// Or, you can get filename sent from backend through req.getResponseHeader('Content-Disposition')
if (typeof window.navigator.msSaveBlob === 'function') {
// If it is IE that support download blob directly.
window.navigator.msSaveBlob(data, defaultFilename);
} else {
var blob = data;
var link = document.createElement('a');
link.href = window.URL.createObjectURL(blob);
link.download = defaultFilename;
document.body.appendChild(link);
link.click(); // create an <a> element and simulate the click operation.
}
}
}
};
req.send(JSON.stringify({test: 'test'}));

Download a file on Autodesk Forge using .NET

I am unsure how to download objects inside a bucket. The file I am currently able to download has a significantly smaller size compared to the file uploaded in the bucket. In addition, I am unable to open the file after it is downloaded. Is there something missing in my code? The following code is what I used to download files.
var element = document.createElement('a');
element.setAttribute('href', '#');
element.setAttribute('download', node.text);
element.style.display = 'none';
document.body.appendChild(element);
element.click();
document.body.removeChild(element);

You refer my answer here (Download BIM360 Docs file using Javascript) to download files from Forge OSS bucket.
In this suggestion, I extended the jQuery function to creates new XMLHttpRequest and passes all the received data back to the jQuery.
/**
*
* jquery.binarytransport.js
*
* #description. jQuery ajax transport for making binary data type requests.
* #version 1.0
* #author Henry Algus <henryalgus#gmail.com>
*
*/
// use this transport for "binary" data type
$.ajaxTransport("+binary", function(options, originalOptions, jqXHR) {
// check for conditions and support for blob / arraybuffer response type
if (window.FormData && ((options.dataType && (options.dataType == 'binary')) || (options.data && ((window.ArrayBuffer && options.data instanceof ArrayBuffer) || (window.Blob && options.data instanceof Blob))))) {
return {
// create new XMLHttpRequest
send: function(headers, callback) {
// setup all variables
var xhr = new XMLHttpRequest(),
url = options.url,
type = options.type,
async = options.async || true,
// blob or arraybuffer. Default is blob
dataType = options.responseType || "blob",
data = options.data || null,
username = options.username || null,
password = options.password || null;
xhr.addEventListener('load', function() {
var data = {};
data[options.dataType] = xhr.response;
// make callback and send data
callback(xhr.status, xhr.statusText, data, xhr.getAllResponseHeaders());
});
xhr.open(type, url, async, username, password);
// setup custom headers
for (var i in headers) {
xhr.setRequestHeader(i, headers[i]);
}
xhr.responseType = dataType;
xhr.send(data);
},
abort: function() {
jqXHR.abort();
}
};
}
});
Afterward, you can simply replace values of filename, bucketKey and YOUR_ACCESS_TOKEN to yours to download files on the website directly. However, it could be very unsafe, please see the comment here
$(function() {
$('a#download').click(function(event) {
event.preventDefault();
const filename = 'hose.rvt';
const bucketKey = 'adn-test';
const settings = {
crossDomain: true,
url: 'https://developer.api.autodesk.com/oss/v2/buckets/' + bucketKey + ' /objects/' + filename,
method: 'GET',
dataType: 'binary',
processData: false,
headers: {
Authorization: 'Bearer YOUR_ACCESS_TOKEN',
Content-Type: 'application/octet-stream'
}
};
$.ajax(settings).done(function (blob, textStatus, jqXHR) {
console.log(blob );
console.log(textStatus);
if( navigator.msSaveBlob )
return navigator.msSaveBlob(blob, filename);
const url = URL.createObjectURL(blob);
const a = document.createElement('a');
a.style = 'display: none';
document.body.appendChild(a);
a.href = url;
a.download = filename;
a.click();
URL.revokeObjectURL(url);
});
});
})

Save response as file

I have WebAPI method which returns HttpResponseMessage with .csv file as Content:
private static HttpResponseMessage FileAsAttachment(string file)
{
var now = DateTime.Now;
var result = new HttpResponseMessage(HttpStatusCode.OK);
result.Content = new StringContent(file);
result.Content.Headers.ContentType = new MediaTypeHeaderValue("application/octet-stream");
result.Content.Headers.ContentDisposition = new ContentDispositionHeaderValue("attachment"); //attachment will force download
result.Content.Headers.ContentDisposition.FileName = string.Format("Report-{0}.csv", now.ToString("MMMM"));
return result;
}
So I have just click function, which make call to server :
$scope.GenerateReport = function() {
var endDate = '2016-04-30';
UserDaysSummary.generateReport({endDate: endDate }, function (result) {
console.log("Export");
});
}
But all that I've got - is a response with data inside.
I've tried to get it as file using this and this answer, but this doesn't change anything.
Preferably, that call to the server has GET method, btw

Is your GenerateReport function returning a promise? Try this:
userDaysSummary.generateReport = function(endDate) {
var defer = $q.defer();
$http.get('path/to/api', { endDate: endDate }, { responseType: 'arrayBuffer' }).then(function(data, status, headers, config) {
var results = {
data: data, //your file is here
headers: headers(), //headers are here
status: status,
config: config
};
//return a success promise containing the response object
defer.resolve(results);
}, function(data, status, headers, config) {
defer.reject(data);
});
return defer.promise;
}
Then, using the promise to download the file:
userDaysSummary.generateReport(endDate).then(function(response) {
//get the file
var octetStreamMime = 'application/octet-stream';
//get the headers' content disposition
var cd = response.headers["content-disposition"];
//get the file name with regex
var regex = /filename[^;=\n]*=((['"]).*?\2|[^;\n]*)/;
var match = regex.exec(cd);
//is there a fiel name?
var fileName = match[1] || "myDefaultFileName.csv";
//replace leading and trailing slashes that C# added to your file name
fileName = fileName.replace(/\"/g, "");
//determine the content type from the header or default to octect stream
var contentType = response.headers["content-type"] || octetStreamMime;
//finally, download it
try {
var blob = new Blob([response.data], {type: contentType});
//downloading the file depends on the browser
//IE handles it differently than chrome/webkit
if (window.navigator && window.navigator.msSaveOrOpenBlob) {
window.navigator.msSaveOrOpenBlob(blob, fileName);
} else {
var objectUrl = URL.createObjectURL(blob);
window.open(objectUrl);
}
} catch (exc) {
console.log("Save Blob method failed with the following exception.");
console.log(exc);
}
}, function(error) {
//an error occurred while trying the API, handle this
});

jQuery.ajax get image from wcf service and display

I'm trying to download and display an image that is returned from a wcf service using jQuery.ajax. I'm not able to work with the data I've received and I'm not sure why. I've tried a lot of things but nothing seems to work.
Here the service :
public Stream DownloadFile(string fileName, string pseudoFileName)
{
string filePath = Path.Combine(PictureFolderPath, fileName);
if (System.IO.File.Exists(filePath))
{
FileStream resultStream = System.IO.File.OpenRead(filePath);
WebOperationContext.Current.OutgoingResponse.ContentType = "application/x-www-form-urlencoded";
return resultStream;
}
else
{
throw new WebFaultException(HttpStatusCode.NotFound);
}
}
Here my ajax call :
$.ajax({
type: "GET",
url: apiURL + serviceDownloadFile.replace('{filename}', filename),
headers: headers,
contentType: "application/x-www-form-urlencoded",
processData : false,
success: function(response) {
var html = '<img src="data:image/jpeg;base64,' + base64encode(response) +'">';
$("#activitiesContainer").html(html);
},
error: function (msg) {
console.log("error");
console.log(msg);
}
});
Putting the url in a <img> tag does display the image properly, but since the service requires an authorization header, the page ask me for credentials each time.
So my question is, what to do this the response data so I can display it ? using btoa(); on the response displays an error :
string contains an invalid character
Thanks.

As suggested by Musa, using XMLHttpRequest directly did the trick.
var xhr = new XMLHttpRequest();
xhr.open('GET', apiURL + serviceDownloadFile.replace('{filename}', filename).replace('{pseudofilename}', fileNameExt), true);
xhr.responseType = 'blob';
xhr.setRequestHeader("authorization","xxxxx");
xhr.onload = function(e) {
if (this.status == 200) {
var blob = this.response;
var img = document.createElement('img');
img.onload = function(e) {
window.URL.revokeObjectURL(img.src); // Clean up after yourself.
};
img.src = window.URL.createObjectURL(blob);
document.body.appendChild(img);
}
};
xhr.send();

using zip.js to read a zip file via xmlhttp/ajax call on Node.js

I am trying to :
Send a zip file via xmlhttp to the client
then read the file using zip.js and render its contents
I successfully receive the binary of the file i.e. the success callback is called but I get and error when I try to do getEntries. I think the error is with the way of sending stream , please help.
Error msg :
Error in reading zip file
My client side code (using angular) :
$http.get(window.location.origin + '/book/'+bookName,{responseType:"Blob"}).
success(function (data , error) {
var a = new Uint8Array(data);
//var dataView = new DataView(data);
//var blob = new Blob(dataView.buffer);
zip.useWebWorkers = true;
zip.workerScriptsPath = '/js/app/';
zip.createReader(new zip.BlobReader(data), function(reader) {
// get all entries from the zip
reader.getEntries(function(entries) { //HERE I GET THE ERROR
if (entries.length) {
// get first entry content as text
entries[0].getData(new zip.TextWriter(), function(text) {
// text contains the entry data as a String
console.log(text);
// close the zip reader
reader.close(function() {
// onclose callback
var a = 0;
});
}, function(current, total) {
// onprogress callback
var a = 0;
});
}
});
},
function(error) {
// onerror callback
var a = 0;
});
})
.error( function (data , error) {
var a = 0;
});
My Server side code on Node:
router.get('/book/:bookName',function (req , res ) {
console.log('Inside book reading block : ' + req.params.bookName);
req.params.bookName += '.zip';
var filePath = path.join(__dirname,'/../\\public\\books\\' ,req.params.bookName );
var stat = fileSystem.statSync(filePath);
res.writeHead(200, {
//'Content-Type': 'application/zip',
'Content-Type': 'blob',
'Content-Length': stat.size
});
var readStream = fileSystem.createReadStream(filePath);
// replace all the event handlers with a simple call to readStream.pipe()
readStream.pipe(res);
});

It is probable that you might have already found a solution. I faced the same problem today and this is how I solved it in plain javascript:
var xhr = new XMLHttpRequest();
xhr.open('GET', 'assets/object/sample.zip', true);
xhr.responseType = 'arraybuffer';
xhr.onload = function(e) {
// response is unsigned 8 bit integer
var responseArray = new Uint8Array(this.response);
var blobData = new Blob([responseArray], {
type: 'application/zip'
});
zip.createReader(new zip.BlobReader(blobData), function(zipReader) {
zipReader.getEntries(displayEntries);
}, onerror);
};
xhr.send();
The problem I see in your code is that you are changing the value to Uint8Array and assigning it to var a, but still use the raw data in blobreader. Also the blob reader required blob and not an array. So you should have converted var a into blob and then used it for reading.