Unable to download blob loaded into an iframe - javascript

Following is my code which sets src attribute of an iframe to the blob url that I have created:-
function downloadFromIframeUsingBody(filebody: any) {
const iframe = document.createElement('iframe');
iframe.setAttribute('style', 'display: none;');
const newurl = window.URL.createObjectURL(new Blob([filebody.data],{type: 'application/pdf'}));
iframe.setAttribute('src', newurl);
const register = () => {
if (iframe.contentWindow) {
setTimeout(function() {
// Clean after 1 minute, by then it should already have started downloading
iframe.parentNode!.removeChild(iframe);
}, 60000);
} else {
setTimeout(register, 100);
}
};
register();
document.body.appendChild(iframe);
}
What I would like is for this iframe to download the blob containing pdf to be downloaded automatically. Currently nothing happens when this gets executed.

If you mean "download" as "save on disk" then just use an HTMLAnchorElement and its download attribute.
Or even handle all the edge cases (old IE and Safari quirks) with the ligthweight FileSaver script.
var blob = new Blob(["I'm just a text file..."], {type: 'plain/text'});
saveAs(blob, 'myFile.txt');
<script src="https://cdnjs.cloudflare.com/ajax/libs/FileSaver.js/2014-11-29/FileSaver.js"></script>
Note that this is true for any cases. iframe hack is just a bad hack that should only be used when it's been determined that no other better ways will work.
Now to explain why it won't work, well, it's because browsers actually are able to display pdf files, and will thus [try to] do it instead of forcing a download.
<iframe src="https://cdn.jsdelivr.net/gh/mozilla/pdf.js/test/pdfs/S2.pdf"></iframe>
(Note that current Chrome seems to have a bug that will make the pdf-reader to fail when in nested iframes, so here is a link to a plunker, where you can see it live in this browser by clicking the expand button on the right panel.

Related

downloaded html page not opening in chrome or edge but in IE and giving noscript error - vue application

In my application, i am trying to download html of current page which is with same domain name. I have written some method to download the html and it is downloading.
But, i have tried to open it in chrome as well as edge and it is not opening. But, in IE it is opening and displaying text of noscript tag (We're sorry but app doesn't work properly without JavaScript enabled.Please enable it to continue.).
I am inputting intranet site URL and clicking the download button. Here is my method below.
downloadHtml() {
let url = this.urlInput; // input text v-model value
fetch(url)
.then((res) => res.text())
.then((html) => this.downloadAsFile("report.html", html)); // by this name it is downloading
},
downloadAsFile(name, text) {
const link = this.createDownloadableLink(name, text);
const clickEvent = new MouseEvent("click");
link.dispatchEvent(clickEvent);
},
createDownloadableLink(fileName, content) {
let link = document.createElement("a");
link.href = 'data:attachment/text,' + encodeURIComponent(document.documentElement.outerHTML);
link.target = '_blank';
link.download = fileName;
return link;
},
**The problems are :
1. The app root signifies the public/index.html and that downloaded html is this one not the current page's html.
2. Chrome or Edge is not opening that html page even i checked browser is javascript enabled.
So, what i have to change the download the current page html?
The problem is that an HTML file in not an application/octet-stream file type. The mime type of an HTML page is text/html
I'm unsure of the way you try to create your download link. I don't have time to test it, but there is the way I do it usually using the createObjectURL API :
async function fetchHTML(url) {
let content = await fetch(url).then(resp => resp.text());
let file = new Blob([content],{type:'text/html'});
let href = window.URL.createObjectURL(file);
let a = document.createElement('a');
a.href = href;
a.setAttribute('download', 'report.html');
document.body.appendChild(a);
a.dispatchEvent(new MouseEvent('click'));
}
Another problem is that you don't append your link into the DOM in the code you provided. So the DOM cannot trigger your mouse event and so starting the download (it's needed by some browsers).
With the good mime type, the file in a proper format and a link in to the dom, it should be ok.

Chromium createObjectUrl from Image comes out as net::ERR_FILE_NOT_FOUND

I know that my code works because I have been using it in firefox. When I switched to chrome, this code snippet has stopped working due to chrome unable to read the url generated by URL.createObjectURL().
export const image_preview = () => {
$('.js-thumbnail').off()
$('.js-thumbnail').on('change', function(event) {
// add event to each file input
const img = $(this).siblings('img')
const url = URL.createObjectURL(event.target.files[0]) // url to user's image
img.attr('src', url)
URL.revokeObjectURL(url) // free the allocated object
})
}
The url itself is generated but chromium fails to load it in my image tag.
Some posts suggests to use webkitURL api instead of URL but that didn't work either. Do you know the cause? Is this also a problem in other browsers as well?
You need to wait for the image has loaded before revoking its URL.
Image resources begin to load in a microtask after we set their src (among other reasons to allow setting crossOrigin properties after we set the src), so when the browser will read the src change, the line URL.revokeObjectURL(url) will already have been called, and the blob:// URL already pointing to nowhere.
So simply do
const img = $(this).siblings('img')
const url = URL.createObjectURL(event.target.files[0]) // url to user's image
img.attr('src', url)
img.one('load', (e) => { URL.revokeObjectURL(url); });

How to show save file dialog in Safari?

I need help. I have an angular app and by using DocRaptor want to generate PDF and save it as file. But I cant trigger the dialog to save file in Safari with any method what I have found on Stack Overflow. Those methods open file in current browser tab and replace site html or open file in new tab. No one cant shows the dialog. Here the examples what I have already tried to use. Environment MacOS - EL Capitan. Safari 9.0.3
Solution #1
var content = 'file content for example';
var blob = new Blob([ content ], { type : 'text/plain' });
$scope.url = (window.URL || window.webkitURL).createObjectURL( blob );
Example jsfiddle. Shows file in current tab. Replaces site. But works in Chrome.
Solution #2
<a target="_self" href="mysite.com/uploads/ahlem.pdf" download="foo.pdf">
Example jsfiddle. Doesnt work at all in Safari. Works in Chrome.
Solution #3
<a class="btn" ng-click="saveJSON()" ng-href="{{ url }}">Export to JSON</a>
and
$scope.saveJSON = function () {
$scope.toJSON = '';
$scope.toJSON = angular.toJson($scope.data);
var blob = new Blob([$scope.toJSON], { type:"application/json;charset=utf-8;" });
var downloadLink = angular.element('<a></a>');
downloadLink.attr('href',window.URL.createObjectURL(blob));
downloadLink.attr('download', 'fileName.json');
downloadLink[0].click();
};
Example Code Snippet. Shows the file content instead of document's html.
Solution #4
function download(text, name, type) {
var a = document.getElementById("a");
var file = new Blob([text], {type: type});
a.href = URL.createObjectURL(file);
a.download = name;
}
Example Code Snippet. Replace document with file content in Safari. Works in Chrome.
And similar Solution #5
function download(text, name, type) {
var a = document.createElement("a");
var file = new Blob([text], {type: type});
a.href = URL.createObjectURL(file);
a.download = name;
a.click();
}
Example jsfiddle. Doesnt work at all in Safari. Works in Chrome.
Also I have tried to use libraries like:
FileSaver - It opens file in Safari instead of document. So you should click Cmd+S. Example.
If we use type 'pplication/octet-stream' the name of file will be unknown or there was be an error 'Failed to load resource: Frame load interrupted'. Issue.
Second library Downloadify - doesnt work in Safari at all. Issue.
Angular library nw-fileDialog - instead of save as it shows choose file. Issue.
DocRaptor has own example with jQuery.
Example with angular in jsfiddle. It works in Chrome but in Safari example doesnt work be cause of error with SAMEORIGIN
Refused to display 'https://docraptor.com/docs' in a frame because it set 'X-Frame-Options' to 'SAMEORIGIN'.
But if we reproduce it on server and change url on 'https://docraptor.com/docs.pdf' it works and open file in new tab and automatically download the file so you cant choose a folder and after download user see white empty screen tab in browser. If we specify form target="_self" it will work perfect, but console will have an error 'Failed to load resource:'.
I will appreciate any help with this problem.
Thanks.
Regards.
Try using Blob file for this:
// Buffer can be response from XMLHttpRequest/Ajax or your custom Int32 data
function download(buffer, filename) {
var file = new Blob([buffer], {
type: 'application/octet-stream' // Replace your mimeType if known
});
var fileReader = new FileReader();
fileReader.onloadend = function(e) {
var converted = e.target.result;
converted.name = filename;
converted.webkitRelativePath = filename;
var iframe = document.createElement('iframe');
iframe.style.display = 'none';
document.body.appendChild(iframe);
iframe.src = converted;
};
fileReader.onerror = function(e) {
throw new Error('Something is wrong with buffer data');
};
fileReader.file = file;
fileReader.readAsDataURL(file);
}
It basically uses filebuffer and download that as an iframe content. Make sure to hook correct mime type so that safari security system will recieved analyse filetype.
Ideally, Solution #2 would be the answer, but the download attribute does not yet have cross-browser support.
So you have to use a <form> to create the download. As you noted, DocRaptor's jQuery example uses this technique.
The SAMEORIGIN error is actually because JSFiddle is running the code in an iFrame with their origin settings. If you run this straight from your Angular application, you shouldn't have any problems.

how to get image name and image size from base64 string image [duplicate]

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?
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.
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();
}
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, …
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)
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
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")
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.
you can add a download attribute to the anchor element.
sample:
<a download="abcd.cer"
href="data:application/stream;base64,MIIDhTC......">down</a>
Using service workers, this is finally possible in the truest sense.
Create a fake URL. For example /saveAs/myPrettyName.jpg
Use URL in <a href, <img src, window.open( url ), absolutely anything that can be done with a "real" URL.
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 );
}
});
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.
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.
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();
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
(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 right-click me and select "Save Link As..." and save as "example.txt". 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.
<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
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 () { });
}
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==

IE 10/11 drops blob object when printing PDF from iframe

I'm trying to implement a pdf print feature based on PDFKit in my web site.
I created a PDF using PDFKit and referenced it via a blobURL with an iframe.
But if I print the iframe, it is empty. (Firefox and Chrome works fine)
IE prints the following warning:
One or more blob urls were revoked by closing the blob for which they were created. these urls will no longer resolve as the data backing the url has been freed.
Here is my code:
var url = this.pdfStream.toBlobURL('application/pdf');
if (navigator.userAgent.match(/firefox/i) !== null){ //Firefox
window.open(url, '_blank');
} else{
$(document.body).append('<iframe id="printPreview" name="printPreview">');
$('iframe#printPreview').url = this.pdfStream.toBlobURL('application/pdf');
$('iframe#printPreview').attr('src', url);
$('iframe#printPreview').load(function(){
window.frames["printPreview"].focus();
window.frames["printPreview"].print();
});
}
Has anybody a workaround for this?
I already tried to open the BlobURL in a new window, but it also fails with IE. I also tried to store the blobURL in a window property, but it also fails.
Thanks!

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