CODEWITHSUNDEEP
javascripthtmlurldata-urisave-as
MontyGomery
MontyGomery

Reputation:

Is there any way to specify a suggested filename when using data: URI?

If for example you follow the link:

data:application/octet-stream;base64,SGVsbG8=

The browser will prompt you to download a file consisting of the data held as base64 in the hyperlink itself. Is there any way of suggesting a default name in the markup? If not, is there a JavaScript solution?

Upvotes: 285

Views: 235574

Answers (18)

AGI-Chandler
AGI-Chandler

Reputation: 35

Yes, it's possible, but it's application dependent.  The RFC allows for any number of attribute=value parameters, and provides some example ideas as well.  Thunderbird does respect a filename=<file.ext> parameter but Firefox does not.  Try testing it yourself.  Here is the stackoverflow logo in svg format from wikimedia commons base64-encoded and formatted in the data URL scheme:

data:image/svg+xml;base64,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

You can copy/paste that into your address bar and you should see stackoverflow's logo rendered.  Try and save it and, in Firefox, it will default to Untitled.svg.

Now, add a filename parameter:

data:image/svg+xml; filename=Stack_Overflow_icon.svg; base64,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

I added spaces too to make it easier to read, which are also valid.  Copy/paste that to your address bar and, in Firefox at least, it will still try to save it as Untitled.svg.

Finally, in Thunderbird, start composing a new HTML message and go to Insert > HTML and give it an img tag with that data: URL for the src attribute:

<img src="data:image/svg+xml; filename=Stack_Overflow_icon.svg; base64,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" />

After you click insert you should see the lovely stackoverflow logo.  Now, just save the message in your Drafts and then head over to it so you can view it as a written e-mail. Right-click on the stackoverflow logo and Save Image as... and what do you know? it will default to saving it as Stack_Overflow_icon.svg for you.

Upvotes: 0

ninjagecko
ninjagecko

Reputation: 91142

(This answer has been made deprecated by newer technology, but will be kept here for historical interest.)

It's kind of hackish, but I've been in the same situation before. I was dynamically generating a text file in javascript and wanted to provide it for download by encoding it with the data-URI.

This is possible with minormajor user intervention. Generate a link <a href="data:...">right-click me and select "Save Link As..." and save as "example.txt"</a>. As I said, this is inelegant, but it works if you do not need a professional solution.

This could be made less painful by using flash to copy the name into the clipboard first. Of course if you let yourself use Flash or Java (now with less and less browser support I think?), you could probably find a another way to do this.

Upvotes: 1

Micha
Micha

Reputation: 1

<a href=.. download=.. > works for left-click and right-click -> save link as..,

but <img src=.. download=.. > doesn't work for right-click -> save image as.. , "Download.jped" is suggested.

If you combine both:<a href=.. download=..><img src=..></a>

it works for left-click, right-click -> save link as.., right-click -> save image as..

You have to write the data-uri twice (href and src), so for large image files it is better to copy the uri with javascript.

tested with Chrome/Edge 88

Upvotes: 0

Dan Fabulich
Dan Fabulich

Reputation: 39593

Use the download attribute:

<a download='FileName' href='your_url'>

The download attribute works on Chrome, Firefox, Edge, Opera, desktop Safari 10+, iOS Safari 13+, and not IE11.

Upvotes: 227

fregante
fregante

Reputation: 31829

HTML only: use the download attribute:

<a download="logo.gif" href="data:image/gif;base64,R0lGODlhAQABAIAAAAAAAP///yH5BAEAAAAALAAAAAABAAEAAAIBRAA7">Download transparent png</a>

Javascript only: you can save any data URI with this code:

function saveAs(uri, filename) {
  var link = document.createElement('a');
  if (typeof link.download === 'string') {
    link.href = uri;
    link.download = filename;

    //Firefox requires the link to be in the body
    document.body.appendChild(link);
    
    //simulate click
    link.click();

    //remove the link when done
    document.body.removeChild(link);
  } else {
    window.open(uri);
  }
}

var file = 'data:image/gif;base64,R0lGODlhAQABAIAAAAAAAP///yH5BAEAAAAALAAAAAABAAEAAAIBRAA7'
saveAs(file, 'logo.gif');

Chrome, Firefox, and Edge 13+ will use the specified filename.

IE11, Edge 12, and Safari 9 (which don't support the download attribute) will download the file with their default name or they will simply display it in a new tab, if it's of a supported file type: images, videos, audio files, …

Upvotes: 62

Chad
Chad

Reputation: 9859

You actually can achieve this, in Chrome and FireFox.

Try the following url, it will download the code that was used.

data:text/html;base64,PGEgaHJlZj0iZGF0YTp0ZXh0L2h0bWw7YmFzZTY0LFBHRWdhSEpsWmowaVVGVlVYMFJCVkVGZlZWSkpYMGhGVWtVaUlHUnZkMjVzYjJGa1BTSjBaWE4wTG1oMGJXd2lQZ284YzJOeWFYQjBQZ3BrYjJOMWJXVnVkQzV4ZFdWeWVWTmxiR1ZqZEc5eUtDZGhKeWt1WTJ4cFkyc29LVHNLUEM5elkzSnBjSFErIiBkb3dubG9hZD0idGVzdC5odG1sIj4KPHNjcmlwdD4KZG9jdW1lbnQucXVlcnlTZWxlY3RvcignYScpLmNsaWNrKCk7Cjwvc2NyaXB0Pg==

Upvotes: -2

owencm
owencm

Reputation: 8894

The following Javascript snippet works in Chrome by using the new 'download' attribute of links and simulating a click.

function downloadWithName(uri, name) {
  var link = document.createElement("a");
  link.download = name;
  link.href = uri;
  link.click();
}

And the following example shows it's use:

downloadWithName("data:,Hello%2C%20World!", "helloWorld.txt")

Upvotes: 16

NeutronenStern
NeutronenStern

Reputation: 71

This one works with Firefox 43.0 (older not tested):

dl.js:

function download() {
  var msg="Hello world!";
  var blob = new File([msg], "hello.bin", {"type": "application/octet-stream"});

  var a = document.createElement("a");
  a.href = URL.createObjectURL(blob);

  window.location.href=a;
}

dl.html

<html lang="en" xmlns="http://www.w3.org/1999/xhtml">

<head>
    <meta charset="utf-8"/>
    <title>Test</title>
    <script type="text/javascript" src="dl.js"></script>
</head>

<body>
<button id="create" type="button" onclick="download();">Download</button>
</body>
</html>

If button is clicked it offered a file named hello.bin for download. Trick is to use File instead of Blob.

reference: https://developer.mozilla.org/de/docs/Web/API/File

Upvotes: 2

Sushama Pradhan
Sushama Pradhan

Reputation: 1

var isIE = /*@cc_on!@*/false || !!document.documentMode; // At least IE6
var sessionId ='\n';
var token = '\n';
var caseId = CaseIDNumber + '\n';
var url = casewebUrl+'\n';
var uri = sessionId + token + caseId + url;//data in file
var fileName = "file.i4cvf";// any file name with any extension
if (isIE)
    {
            var fileData = ['\ufeff' + uri];
            var blobObject = new Blob(fileData);
            window.navigator.msSaveOrOpenBlob(blobObject, fileName);
    }
    else //chrome
    {
        window.requestFileSystem = window.requestFileSystem || window.webkitRequestFileSystem;
         window.requestFileSystem(window.TEMPORARY, 1024 * 1024, function (fs) {
            fs.root.getFile(fileName, { create: true }, function (fileEntry) { 
                fileEntry.createWriter(function (fileWriter) {
                    var fileData = ['\ufeff' + uri];
                    var blob = new Blob(fileData);
                    fileWriter.addEventListener("writeend", function () {
                        var fileUrl = fileEntry.toURL();
                        var link = document.createElement('a');
                        link.href = fileUrl;
                        link.download = fileName;
                        document.body.appendChild(link);
                        link.click();
                        document.body.removeChild(link);
                    }, false);
                    fileWriter.write(blob);
                }, function () { });
            }, function () { });
         }, function () { });
    }

Upvotes: -1

Alnitak
Alnitak

Reputation: 339975

According to RFC 2397, no, there isn't.

Nor does there appear to be any attribute of the <a> element that you can use either.

However HTML5 has subsequently introduced the download attribute on the <a> element, although at the time of writing support is not universal (no MSIE support, for example)

Upvotes: 42

Adria
Adria

Reputation: 9061

Using service workers, this is finally possible in the truest sense.

  1. Create a fake URL. For example /saveAs/myPrettyName.jpg
  2. Use URL in <a href, <img src, window.open( url ), absolutely anything that can be done with a "real" URL.
  3. Inside the worker, catch the fetch event, and respond with the correct data.

The browser will now suggest myPrettyName.jpg even if the user opens the file in a new tab, and tries to save it there. It will be exactly as if the file had come from the server.

// In the service worker
self.addEventListener( 'fetch', function(e)
{
    if( e.request.url.startsWith( '/blobUri/' ) )
    {
        // Logic to select correct dataUri, and return it as a Response
        e.respondWith( dataURLAsRequest );
    }
});

Upvotes: 9

kgividen
kgividen

Reputation: 79

Here is a jQuery version based off of Holf's version and works with Chrome and Firefox whereas his version seems to only work with Chrome. It's a little strange to add something to the body to do this but if someone has a better option I'm all for it.

var exportFileName = "export-" + filename;
$('<a></a>', {
    "download": exportFileName,
    "href": "data:," + JSON.stringify(exportData, null,5),
    "id": "exportDataID"
}).appendTo("body")[0].click().remove();

Upvotes: 4

Holf
Holf

Reputation: 6441

Chrome makes this very simple these days:

function saveContent(fileContents, fileName)
{
    var link = document.createElement('a');
    link.download = fileName;
    link.href = 'data:,' + fileContents;
    link.click();
}

Upvotes: 72

sherpya
sherpya

Reputation: 4936

I've looked a bit in firefox sources in netwerk/protocol/data/nsDataHandler.cpp

data handler only parses content/type and charset, and looks if there is ";base64" in the string

the rfc specifices no filename and at least firefox handles no filename for it, the code generates a random name plus ".part"

I've also checked firefox log

[b2e140]: DOCSHELL 6e5ae00 InternalLoad data:application/octet-stream;base64,SGVsbG8=
[b2e140]: Found extension '' (filename is '', handling attachment: 0)
[b2e140]: HelperAppService::DoContent: mime 'application/octet-stream', extension ''
[b2e140]: Getting mimeinfo from type 'application/octet-stream' ext ''
[b2e140]: Extension lookup on '' found: 0x0
[b2e140]: Ext. lookup for '' found 0x0
[b2e140]: OS gave back 0x43609a0 - found: 0
[b2e140]: Searched extras (by type), rv 0x80004005
[b2e140]: MIME Info Summary: Type 'application/octet-stream', Primary Ext ''
[b2e140]: Type/Ext lookup found 0x43609a0

interesting files if you want to look at mozilla sources:

data uri handler: netwerk/protocol/data/nsDataHandler.cpp
where mozilla decides the filename: uriloader/exthandler/nsExternalHelperAppService.cpp
InternalLoad string in the log: docshell/base/nsDocShell.cpp

I think you can stop searching a solution for now, because I suspect there is none :)

as noticed in this thread html5 has download attribute, it works also on firefox 20 http://www.whatwg.org/specs/web-apps/current-work/multipage/links.html#attr-hyperlink-download

Upvotes: 21

cuixiping
cuixiping

Reputation: 25419

you can add a download attribute to the anchor element.

sample:

<a download="abcd.cer"
    href="data:application/stream;base64,MIIDhTC......">down</a>

Upvotes: 11

Fabian B.
Fabian B.

Reputation: 70

There is a tiny workaround script on Google Code that worked for me:

http://code.google.com/p/download-data-uri/

It adds a form with the data in it, submits it and then removes the form again. Hacky, but it did the job for me. Requires jQuery.

This thread showed up in Google before the Google Code page and I thought it might be helpful to have the link in here, too.

Upvotes: 4

silex
silex

Reputation: 4320

Look at this link: http://lists.w3.org/Archives/Public/uri/2010Feb/0069.html

Quote:

It even works (as in, doesn't cause a problem) with ;base64 at the end
like this (in Opera at least):

data:text/plain;charset=utf-8;headers=Content-Disposition%3A%20attachment%3B%20filename%3D%22with%20spaces.txt%22%0D%0AContent-Language%3A%20en;base64,4oiaDQo%3D

Also there is some info in the rest messages of the discussion.

Upvotes: 5

Lightness Races in Orbit
Lightness Races in Orbit

Reputation: 385325

No.

The entire purpose is that it's a datastream, not a file. The data source should not have any knowledge of the user agent handling it as a file... and it doesn't.

Upvotes: 12

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