Seeding files from browser - javascript

I'm trying to allow a user to select a file from their computer and start seeding it, I've followed the example here. I've used a normal input rather than using drag and drop as I couldn't get it to work.
Now whenever a file is selected I get this error:
Uncaught Error: filesystem paths do not work in the browser
How can I start seeding from a user's computer without uploading the file to my server?

I think you tryed reading a file with file:///, but this not possible for security reasons. A file must be selected or drap&droped from the user.
The simplest solution is with a button:
function readFile(evt) {
var file = evt.target.files[0]
if (!file) {
return
}
var reader = new FileReader()
reader.onload = evt => {
var contents = evt.target.result
console.log(contents)
}
reader.readAsText(file)
}
<input type="file" onchange="readFile.call(this, event)" />
With this snippet you can read a file without any interaction with a server and thats ideal for a serverless techlology like torrent.

Related

How to upload a file to FTP server with javascript?

For minimal example, I have
Host: 111.222.111.123
Username: user_name
Password: pass_word
File to upload is selected with HTML input element
I can upload the file manually to the target directory on the server with a client like FileZilla.
The target directory is where the file should be uploaded. Its location on the Internet is https://nameofsite/targetdir/, so the file should be reachable on the internet for anyone as https://nameofsite/targetdir/1.html.
But is it possible to upload the file to the server with javascript?
I tried this example taking to account #mcrdy455's answer, but anyway it's not clear what the FtpConnection is:
<input id="fileForUpload" type=file onchange="upload()">
<div id="fileContents"></div>
<script>
function upload() {
var file = document.getElementById("fileForUpload").files[0];
if (file) {
var reader = new FileReader();
reader.readAsText(file, "UTF-8");
reader.onload = function (evt) {
document.getElementById("fileContents").innerHTML = evt.target.result;
var ftp = new FtpConnection("ftp://111.222.111.123/");
ftp.login("user_name", "pass_word");
ftp.put(file, "1.html");
ftp.close();
file.close();
}
}
}
</script>
Uncaught ReferenceError: FtpConnection is not defined
After searching on the Internet, I'm still not sure what project FtpConnection belongs to. Other examples use URLs instead of IP addresses (111.222.111.123).
E.g. Ftp.createCORSRequest('POST', "http://www.ftpjs.xyz/upload.aspx") in this one. I would like not to complicate things (with CORS) and use the 111.222.111.123 address.
If FileZilla can do the job, why couldn't javascript do it? How?
The JavaScript code can NOT access files from your filesystem, use an input type file, and read the file through the FileReader: You can fine more info on how to do this here, Once you have the correct file/blob object you code should work

Is it possible to extract text from PDF from File API on input rather than getting the stored document?

I am trying to build a web-based utility that allows a user to 'choose' a system file utilizing <input type="file"> and immediately extract text data from the file without having to upload the file on to the server. I will then parse the text from the file for multiple applications.
I have come across this method for extracting or scraping text from a PDF file : https://ourcodeworld.com/articles/read/405/how-to-convert-pdf-to-text-extract-text-from-pdf-with-javascript
However, this requires a file be stored and accessed using an HTTP request.
So far I am able to read the PDF file using the File API, but I am not able to interact with the text content.
HTML
<input type="file" name="File Upload" id="tpdfFileUpload" accept=".pdf" />
Javascript
document.getElementById('pdfFileUpload').addEventListener('change', upload, false);
function upload(evt) {
var file = evt.target.files[0];
var reader = new FileReader();
reader.readAsText(file);
reader.onload = function(event) {
var textData = event.target.result;
//
// INSERT Code to convert textData into usable text.
//
};
reader.onerror = function() {
alert('Unable to read ' + file.fileName);
};
}
I played around with PDF.js but am having a hard time finding something that would work for this use case.

How to get full path to user's type="file" using jQuery Fileupload

Im trying to build file preview feature before file being uploaded to the server.
Im stucked with the problem of reading file from the user's computer, not a server
Im usuing jquery Fileupload which fires the file processing on the change function
return $('#new_order_file').fileupload({
change: function(e, data) {
return $.each(data.files, function(index, file) {
read_file(file);
console.log(file)
});
},
});
Log gives File - name, size, type, proto and LastmodifiedDate
Than, this part is tricky for me, I know that I have to use FileReader() but Im not sure how to
function read_file(f){
var reader = new FileReader();
reader.onload = function(e) {
$('#CO-show-model').css('display', 'block');
loaded(f.name, e.target.result);
};
reader.readAsArrayBuffer(f);
}
Next, loaded function is for displaying the file model using three.js
function loaded(file) {
var uploaded_file = file // gives 404
// var uploaded_file = './stl/test-file.stl' // ASCII test
}
The fucntion itself is good, I tested it with an hardcoded path to some test file. But the problem is that it was on a server. Now, script gives an 404 for http://example.com/filename.stl which is true, because I pass file.name there. If I just pass file, it gives 404 for http://example.com/[object%20File]
Edit 1:
I tried suggest ReadAsDataUrl, but seems to be that it's not supported by three.js. Also, the FileReader() seems to be ok
Your file is an object so you have to get the right attribute from it.
Take a look here Filereader Mozilla documentation
It's a security feature. Browsers will not give you the actual local url to the file you are uploading.
See How to get full path of selected file on change of <input type=‘file’> using javascript, jquery-ajax?
Edit: Maybe what you are looking for is this question instead? What is the preferred method for loading STL files in Three.js

Web Development Displaying Local Files

Based on research, I've found tutorials, such as this one from Eric Bidelman, that go into FileReader usage. Instead of local files, these tutorials use files provided by the user. Modifying these examples to try and display local files were not successful.
After some research I've found that most browsers by default do not allow access to local files [1]. Some recommend using unsafe modes for testing, but that's not what I'm looking for as that would apply to only my testing [2].
Currently I allow the download of log files. My goal here with FileReader was to provide a way to view the files as well. Is there a way to achieve this? I'm coming up with blanks and have almost resigned to only allowing downloads instead of adding viewing. The following is example code of local file reading. This code fails since 'logpath' is not of type blob. I believe my question doesn't really require code, but I provided an example anyway.
HTML Code
<select name="loglist" id="loglist" onchange="run()" size="2">
<option>stack1.log</option>
<option>stack2.log</option>
</select>
Javascript
function run() {
var reader = new FileReader();
log = document.getElementById( "loglist" ).value;
var logdir = "/var/log/";
var logpath = logdir.concat(log);
reader.onload = function() {
logtext = reader.result;
alert(logtext);
}
reader.readAsText(logpath);
}
There is no way for JavaScript, embedded in a webpage, to access files on the user's local system other than through the File API when the user selects the file using a file input. It is not possible for the page to supply the file name to be opened.
var inp = document.querySelector("input");
inp.addEventListener("change", show);
function show(e) {
var f = this.files[0];
var r = new FileReader();
r.addEventListener("load", display);
r.readAsText(f);
function display(e) {
document.body.appendChild(
document.createTextNode(
e.target.result
)
);
}
}
<input type="file" id="input">

Filesystem API - Upload from local drive to local filesystem

Ive read a lot about the filesystem API and HTML5, but i just couldn't find a working solution so i ask you guys:
I want to have a file upload form, drag drop or regular input box doesnt matter, however i want to select a file, and after uploading it should take the file or a whole folder and "upload" it to the filesystem located on the clients computer. The upload is in brackets because i actually want to copy the file/folder to the clients local file system.
Is it even possible? Because i want to make an application, where a user can upload his files such as music or large videos and movies to his local filesystem and edit/watch etc them in my application. I know i have to upload those big files i have to cut them into pieces and load them stacked up, but i just want to start little :)
Thanks in advance
There's indeed little information on this subject at the moment, so I put together an example that combines:
Using the webkitdirectory attribute on <input type="file">.
This allows the user to select a directory using an appropriate dialog box.
Using the Filesystem API.
This is about the sandboxed filesystem which allows you to store files on the client's machine.
Using the File API.
This is the API that allows you to read files. The files are accessible through an <input type="file"> element, through a transfer using drag and drop, or through the Filesystem API.
As these are currently only working nicely in Chrome, I used the webkit prefix where necessary.
http://jsfiddle.net/zLna6/3/
The code itself has comments which I hope are clear:
var fs,
err = function(e) {
throw e;
};
// request the sandboxed filesystem
webkitRequestFileSystem(
window.TEMPORARY,
5 * 1024 * 1024,
function(_fs) {
fs = _fs;
},
err
);
// when a directory is selected
$(":file").on("change", function() {
$("ul").empty();
// the selected files
var files = this.files;
if(!files) return;
// this function copies the file into the sandboxed filesystem
function save(i) {
var file = files[i];
var text = file ? file.name : "Done!";
// show the filename in the list
$("<li>").text(text).appendTo("ul");
if(!file) return;
// create a sandboxed file
fs.root.getFile(
file.name,
{ create: true },
function(fileEntry) {
// create a writer that can put data in the file
fileEntry.createWriter(function(writer) {
writer.onwriteend = function() {
// when done, continue to the next file
save(i + 1);
};
writer.onerror = err;
// this will read the contents of the current file
var fr = new FileReader;
fr.onloadend = function() {
// create a blob as that's what the
// file writer wants
var builder = new WebKitBlobBuilder;
builder.append(fr.result);
writer.write(builder.getBlob());
};
fr.onerror = err;
fr.readAsArrayBuffer(file);
}, err);
},
err
);
}
save(0);
});
$("ul").on("click", "li:not(:last)", function() {
// get the entry with this filename from the sandboxed filesystem
fs.root.getFile($(this).text(), {}, function(fileEntry) {
// get the file from the entry
fileEntry.file(function(file) {
// this will read the contents of the sandboxed file
var fr = new FileReader;
fr.onloadend = function() {
// log part of it
console.log(fr.result.slice(0, 100));
};
fr.readAsBinaryString(file);
});
}, err);
});
That is not possible, exactly, but your app can still probably work. Reading the file is possible through a file input form element, but writing the file back to disk is where you'll run into trouble.
The two ways your browser can write to disk are 1) downloading a file and 2) the HTML5 filesystem API. Option #1 obviously doesn't let your application choose the destination and option #2 only works with browser-created sandbox filesystems. That restriction might not be a deal-breaker for you -- it just means that the folders that your app uses will be buried somewhere in your browser's data files.
Also, the Filesystem API is currently Chrome-only (but it is an open standard). If you want cross-platform support, maybe you can use IndexedDB. You could use localStorage, but Chrome has a hard 5MB limit, which would be terrible for a media application.

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