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Open downloaded file in another application (web-app)

I am building a web application (PWA) using Javascript. I want the application to automatically open downloaded files, such as PDF, DOCX, etc., in an external standard application such as Adobe Reader and Word.
Is there a function in Javascript that solves my problem?
At the moment, the application simply downloads the file to the device.
Unfortunately, I do not have much experience with Javascript, so I apologize if this is a stupid question.
XHR.responseType = 'blob';
XHR.onload = function() {
var data = this.response;
var a = document.createElement('a');
a.href = window.URL.createObjectURL(data);
a.download = fileName;
a.dispatchEvent(new MouseEvent('click'));
};

Javascrip service worker blob

I am trying to download a file in a service worker. The file came from a blob.
I already know that i can download a blob by doing this
var urlCreator = window.URL || window.webkitURL;
var blobURL = urlCreator.createObjectURL(blob, { type: "octet/stream" });
or by using something like FileSaver.js
But today, i am trying to "render" the bytes array of the blob in the page and force the browser to download the document.
Why ?
I am trying to do that because, some browser that i am trying to reach do not support url like "blob:https:......"
So i try to find a way to render the bytearrays of my blob directly in javascript.
I know that i can push headers with worker, but not sure that is the right strategie.
I also try something like that
var xhr = new XMLHttpRequest();
xhr.open('GET', obj.URL, false);
xhr.overrideMimeType("application/octet-stream");
//xhr.setRequestHeader("Accept", "application/octet-stream");
xhr.responseType = "arraybuffer";
xhr.onload = function (e) {
self.Response(xhr.response);
//if (this.status == 200) {
// var myBlob = this.response;
// // myBlob is now the blob that the object URL pointed to.
//}
};
xhr.send();
In my worker.js
ps: Please avoid to told me, send you base64 blob content to your server and send back the file to the browser, i would like to find a pure javascript solution.
Is it possible ?

Using Simple Webaudiorecorder.js in R/Shiny and posting the recording to the server

I am using WebAudioRecorder.js for making online recordings in an R Shiny app, see:
https://github.com/addpipe/simple-web-audio-recorder-demo
As a format, I chose the wave format, and in the JavaScript code, the recording is obtained as a blob. I would like the program to save this blob on the server without any dialog.

Here, you shouldn't set the hole filePath in javascript, you should give it a filename and then php should put it in the correct folder.
function uploadWaveBlob (blob, encoding) {
var xhr = new XMLHttpRequest();
var formData = new FormData();
var fileName = Date().toISOString() + '.' + encoding;
formData.append("Wav", blob, fileName);
xhr.open('POST', uploadUrl);
xhr.onload = function () {
console.log('xhr complete');
};
xhr.send(formData);
}
imagine if i would upload something to like /etc/hosts or something

The following site gives code that shows how to upload a blob to the server:
https://gist.github.com/primaryobjects/d6cdf5d31242a629b0e4cda1bfc4bff9
The complete solution is available at:
https://github.com/heeringa0/simple-web-audio-recorder
and shows how to integrate the Simple WebAudioRecorder.js in an R Shiny app where the recording is saved to the server.

reading an object URL produced in a worker with IE

I have a webworker that is producing a CSV for downloading, and to conserve memory I only have it return the URL it produces from teh blob..
My worker code looks something like::
var blob = new Blob([ResultOfSomeWork()],{type:'text/csv'});
URL.createObjectURL(blob);
self.postMessage({url:blob.url});
My goal is to just be able to download it in firefox and chrome this is very easy as I can just set up an invisible <a> and have it be clicked to download it.
For IE10 I want to use msSaveBlob but I need a blob which I don't want to transfer.
How can I download a object dataurl in IE10?

So I found a solution that works. Apparently, I can XHR and read the content back in my main thread.
worker.onmessage = function(event){
var url = event.data.url;
var xhr = new XMLHttpRequest();
xhr.open('GET', url, true);
xhr.responseType='blob';
xhr.onload = function(){
msSaveBlob(xhr.response, fileName +'.csv');
};
xhr.send();
}
While this feels extremely complicated it works well in practice and is really fast.

How to get the size and duration of an mp3 file?

I need to calculate the total length of an mp3 file.
Currently I am using a PHP class which I found # http://www.zedwood.com/article/php-calculate-duration-of-mp3.
This is working perfectly if the mp3 file in same server.
but if I have a URL from other site it throwing error. Please help me.
Is there any JavaScript J-Query function to get the length of the mp3 file
<?php include("mp3.class.php");
$f = 'http://cdn.enjoypur.vc/upload_file/5570/5738/5739/7924/Blue%20Eyes%20-%20Yo%20Yo%20Honey%20Singh%20(PagalWorld.com)%20-192Kbps%20.mp3';
$m = new mp3file($f);
$a = $m->get_metadata();
if ($a['Encoding']=='Unknown')
echo "?";
else if ($a['Encoding']=='VBR')
print_r($a);
else if ($a['Encoding']=='CBR')
print_r($a);
unset($a);
?>

Here's how you can get mp3 duration using Web Audio API:
const mp3file = 'https://raw.githubusercontent.com/prof3ssorSt3v3/media-sample-files/master/doorbell.mp3'
const audioContext = new (window.AudioContext || window.webkitAudioContext)()
const request = new XMLHttpRequest()
request.open('GET', mp3file, true)
request.responseType = 'arraybuffer'
request.onload = function() {
audioContext.decodeAudioData(request.response,
function(buffer) {
let duration = buffer.duration
console.log(duration)
document.write(duration)
}
)
}
request.send()

There is actually a library that can run at client-side, attempting to fetch just enough of the MP3 to read the ID3 tags:
http://github.com/aadsm/JavaScript-ID3-Reader
or
Try
HTML File API.
http://lostechies.com/derickbailey/2013/09/23/getting-audio-file-information-with-htmls-file-api-and-audio-element/

Perhaps the simplest solution is to use the audio html element to get the time duration and to obtain the size directly from the file returned by the FileReader object. A code example of this approach is shown below.
One down side of this and all the other solutions presented so far is the 10-20 second delay it takes for the audio tag's durationchanged event to fire when loading large, eg > 200MB files. Clearly there is a faster way to get this info because the duration is shown immediately when the file is entered into the browser as a file:///.... URL.
function checkMp3SizeAndDuration()
{
var files = document.getElementById('upload-file').files;
var file = files[0];
if (file.size > MAX_FILE_SIZE) {
return;
}
var reader = new FileReader();
var audio = document.createElement('audio');
reader.onload = function (e) {
audio.src = e.target.result
audio.addEventListener('durationchange', function() {
console.log("durationchange: " + audio.duration);
},false);
audio.addEventListener('onerror', function() {
alert("Cannot get duration of this file.");
}, false);
};
reader.readAsDataURL(file);
});

Having not been able to find something that was fast and didn't require a bunch of extra boilerplate code, I tweaked an existing server side javascript utility to run directly in the browser. Demo code is available at: https://github.com/eric-gilbertson/fast-mp3-duration

A Famous and Very SPI that you can use MP3 SPI
and the code is also very simple
File file = new File("filename.mp3");
AudioFileFormat baseFileFormat = AudioSystem.getAudioFileFormat(file);
Map properties = baseFileFormat.properties();
Long duration = (Long) properties.get("duration");

Use getID3() PHP library that works for VBR files as well.
This link help you sourceforge.net.
It's very much active in development.