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Download Word .docx as Blob file from Angular on mobile devices

I am trying to download .docx file from REST API (.NET Core FileContentResult) in Angular application. Everything is working fine on PC, but there is problem with downloading .docx files in VMware Workspace ONE Web browser (didn't try standard browsers like Chrome or Safari, it looks like there is just Android WebView). It is company application and this browser is the only one allowed.
The problem is only with .docx files. Files like PDF, .doc and .xlsx (created by ClosedXML) are working fine.
REST API call (also tried with 'arraybuffer' instead of 'blob' and created Blob object in client, but problem persists)
this.httpClient.get(requestUrl, {
responseType: 'blob',
observe: 'response'
});
Then I save response body with FileSaver.
generateDocument(file: string | Blob, name: string): void {
FileSaver.saveAs(file, name);
}
I also tried approach that creates link and click on it (it does not work).
Solution with using window.open(blobUrl) is not working.
EDIT:
I got information that it is not working at all in iOS with same browser. Users get error message "Link is invalid."
Can someone help me with this issue? Thanks.

If you can retrieve obtain an ArrayBuffer, this could be used to initiate the download with those bytes:
Test here: https://batman.dev/static/70085191/
async function downloadUrl(url) {
downloadBuffer(
await (await fetch(url)).arrayBuffer()
)
}
function downloadBuffer(arrayBuffer) {
const a = document.createElement('a')
a.href = URL.createObjectURL(new Blob(
[ arrayBuffer ],
{ type: 'application/vnd.openxmlformats-officedocument.wordprocessingml.document' }
))
a.download = 'my-file.docx'
a.click()
}

Flutter: cannot download file from object url in webview

I need to download, from a mobile app developed in flutter 1.22.2, a file generated by a php script. The file is available in blob format.
The javascript code in the web page is:
response.blob()
.then(blob => URL.createObjectURL(blob))
.then(url => {
let a = document.createElement('a');
a.href = url;
a.download = 'modulo-' + JobRiskIden + '.pdf';
a.target = '_blank';
document.body.appendChild(a);
a.click()
a.remove();
})
Where "response" variable is the response from a fetch to a php page that generates the file.
I followed the instructions from this stackoverflow question:
Flutter WebView blob pdf download
The download works fine on iOS but an issue is present on Android (test done with compileSdkVersion 29): when I tap on the download link the debugger prints this message:
{message: Not allowed to load local resource: blob:https://apps.badgebox.com/62edb40f-4407-4d3b-8427-587ea133b778, messageLevel: 3}
Can someone help me to solve this issue?

How can I retrieve a file from the file system using React Native, for conversion to base64 and http posting as JSON?

I am using the react native template from this article. The code is all available on Github here.
You can use the app to record audio and save to the file system. I figured out how to retrieve the file URIs, but I'm finding it impossible to get the actual contents of the file itself. All I want to do is retrieve the actual file contents as a binary or ascii or hex string or whatever (it's a .m4a file), so I can convert it to base64 encoding and then post it as JSON to my server. Here's what my code looks like:
/src/screens/RecordAudioScreen/RecordAudioScreenContainer.js
onEndRecording: props => async () => {
try {
// here is the URI
console.log("HERE IS THE URI!!");
const audio_data = "URI: " + props.recording._uri;
// Help needed here
// retrieve file contents from the Android/iOS file system
// Encode as base64
audio_data = ... // ???????
// this works already, posts to the server
fetch("https://myserver.com/accept_file",
{
headers: {
'Accept': 'application/json',
'Content-Type': 'application/json'
},
method: "POST",
body: JSON.stringify({user_id: 1, audio_data: audio_data})
})
.then(function(res){ console.log(res) })
.catch(function(res){ console.log(res) });
console.log("FINISHED POST REQUEST!!!")
await props.recording.stopAndUnloadAsync();
await props.setAudioMode({ allowsRecordingIOS: false });
} catch (error) {
console.log(error); // eslint-disable-line
}
if (props.recording) {
const fileUrl = props.recording.getURI();
props.recording.setOnRecordingStatusUpdate(null);
props.setState({ recording: null, fileUrl });
}
},
I've already tried a bunch of stuff with no success. Ideally I just get the file contents from the File system, convert to base64 and post it off all in this method just in javascript, but this is seemingly very difficult for what should be a pretty standard thing to do in an app based framework.
Here's some stack overflow questions on React Native Fetch Blob which I couldn't make work Fetch Blob 1 Fetch Blob 2
I've tried using React Native Fs, but I can't get it to load properly, I got super bogged down in stuff I didn't understand after trying to eject the app. I'd prefer a plain React Native solution if possible.
I've also tried some code using FormData but couldn't get that to work either.
Maybe the answer is kind of like this question about retrieving images from firebase? I don't know, this is my first attempt at doing anything in React.
It might also have something to do with the "file://" prefix in the URI that gets generated because there's a lot of questions discussing removing that (only for Android, or only for iOS I'm not too clear).
Converting to base64 will be done with something like this, but I need the actual file contents first:
Very appreciative of any help.

Some time ago I wrote a simple example of a record voice app.
To get the files I used this method:
import RNFS from 'react-native-fs';
(...)
getFiles() {
RNFS.readDir(AudioUtils.DocumentDirectoryPath)
.then((result) => {
this.setState({recordedFiles: result});
return Promise.all([RNFS.stat(result[0].path), result[0].path]);
})
.catch((err) => {
console.log(err.message, err.code);
});
}
It worked just fine.
Here's the full example https://github.com/soutot/react-native-voice-record-app
Let me know if it helped. Otherwise we can try a different approach

Convert static image to Base64 in ReactNative

I have static image which i need to convert in Base64 and then send it to Android/iOS native code.
If i select an image from file i am able to send it to native code and convert that to Base64.
But what if i have static image and then send it to native code.
<Image source={require('./img/icon.png')}/>
I want icon.png to be sent in Android/iOS native module.
I have done native coding, it is something like this
#ReactMethod
public void filterBase64(String base64, Callback stringCallback) {
}
But stucked at how to send Base64
I have checked react-native-image-to-base64 but not able to get solution, when i use
NativeModules.RNImageToBase64.getBase64String(uri, (err, base64) => {
// Do something with the base64 string
})
It shows error undefined is not an object

With the help of RNFS plugin you can access React Native assets and convert them to Base64.
var RNFS = require('react-native-fs')
base64data = await RNFS.readFile('./img/icon.png', 'base64').then();
console.log(base64data);

upload image file from jquery to node.js

I am trying to upload a file from andriod application, using Jquery to node.js using express..
My client side code is:
function uploadData(win) {
var padI = imagedata.length-1
while( '=' == imagedata[padI] ) {
padI--
}
var padding = imagedata.length - padI - 1
var user = load('user')
$.ajax({
url:'http://'+server+'/lifestream/api/user/'+user.username+'/upload',
type:'POST',
contentType: false,
processdata:false,
data:imagedata,
success:win,
error:function(err){
showalert('Upload','Could not upload picture.')
},
})
}
I have used post form without any content type because if i use multipart/form-data it says error about boundary ..
my server side code using node.js is:
function upload(req,res) {
var picid=uuid()
console.log('Got here..' + __dirname)
//console.log('Image file is here ' + req.files.file.path)
// console.log('local name: ' + req.files.file.name)
var serverPath = __dirname+'/images/' + picid+'.jpg'
fs.rename(
req.files.file.path,
serverPath,
function(error) {
if (error) {
console.log('Error '+error)
res.contentType('text/plain')
res.send(JSON.stringify({error: 'Something went wrong saving to server'}))
return;
}
// delete the /tmp/xxxxxxxxx file created during download
fs.unlink(req.files.file.path, function() { })
res.send(picid)
}
)
}
when the file comes to server, it gives an error of res.files.file is undefined ..
I have searched alot of forums, they say that res.files.file is only access when contenttype is multipart/form-data but then the boundary problem occurs
Any help on that is highly appreciated

Boundary is a special sequence of characters that separates your binary data.
You should submit MIME type as multipart/form-data, as well as set your imagedata to FormData() type (from your snippet it's not clear if it is FormData type).
Here are similar issues and solutions:
How to set a boundary on a multipart/form-data request while using jquery ajax FormData() with multiple files
jQuery AJAX 'multipart/form-data' Not Sending Data?

A great alternative to writing this code is to use filepicker.io This allows you to connect to yoru own s3 bucket. When the file is saved, you get back a callback with the S3 url, you can then simply pass that url to your node api, and save it. I have used this to avoid having to write extra server code for handling file uploads. Extra bonus, if you need to do this with images, and want users to be able to edit the images, you can use Aviary which allows an image to be edited locally, and you then get back another s3 url, that you can then save to your server..