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I'm playing with the idea of making a completely JavaScript-based zip/unzip utility that anyone can access from a browser. They can just drag their zip directly into the browser and it'll let them download all the files within. They can also create new zip files by dragging individual files in.
I know it'd be better to do it serverside, but this project is just for a bit of fun.
Dragging files into the browser should be easy enough if I take advantage of the various methods available. (Gmail style)
Encoding/decoding should hopefully be fine. I've seen some as3 zip libraries so I'm sure I should be fine with that.
My issue is downloading the files at the end.
window.location = 'data:jpg/image;base64,/9j/4AAQSkZJR....'
this works fine in Firefox but not in Chrome.
I can embed the files as images just fine in chrome using <img src="data:jpg/image;ba.." />, but the files won't necessarily be images. They could be any format.
Can anyone think of another solution or some kind of workaround?
If you also want to give a suggested name to the file (instead of the default 'download') you can use the following in Chrome, Firefox and some IE versions:
function downloadURI(uri, name) {
var link = document.createElement("a");
link.download = name;
link.href = uri;
document.body.appendChild(link);
link.click();
document.body.removeChild(link);
delete link;
}
And the following example shows it's use:
downloadURI("data:text/html,HelloWorld!", "helloWorld.txt");
function download(dataurl, filename) {
const link = document.createElement("a");
link.href = dataurl;
link.download = filename;
link.click();
}
download("data:text/html,HelloWorld!", "helloWorld.txt");
or:
function download(url, filename) {
fetch(url)
.then(response => response.blob())
.then(blob => {
const link = document.createElement("a");
link.href = URL.createObjectURL(blob);
link.download = filename;
link.click();
})
.catch(console.error);
}
download("https://get.geojs.io/v1/ip/geo.json","geoip.json")
download("data:text/html,HelloWorld!", "helloWorld.txt");
Ideas:
Try a <a href="data:...." target="_blank"> (Untested)
Use downloadify instead of data URLs (would work for IE as well)
Want to share my experience and help someone stuck on the downloads not working in Firefox and updated answer to 2014.
The below snippet will work in both firefox and chrome and it will accept a filename:
// Construct the <a> element
var link = document.createElement("a");
link.download = thefilename;
// Construct the uri
var uri = 'data:text/csv;charset=utf-8;base64,' + someb64data
link.href = uri;
document.body.appendChild(link);
link.click();
// Cleanup the DOM
document.body.removeChild(link);
Here is a pure JavaScript solution I tested working in Firefox and Chrome but not in Internet Explorer:
function downloadDataUrlFromJavascript(filename, dataUrl) {
// Construct the 'a' element
var link = document.createElement("a");
link.download = filename;
link.target = "_blank";
// Construct the URI
link.href = dataUrl;
document.body.appendChild(link);
link.click();
// Cleanup the DOM
document.body.removeChild(link);
delete link;
}
Cross-browser solutions found up until now:
downloadify -> Requires Flash
databounce -> Tested in IE 10 and 11, and doesn't work for me. Requires a servlet and some customization. (Incorrectly detects navigator. I had to set IE in compatibility mode to test, default charset in servlet, JavaScript options object with correct servlet path for absolute paths...) For non-IE browsers, it opens the file in the same window.
download.js -> http://danml.com/download.html Another library similar but not tested. Claims to be pure JavaScript, not requiring servlet nor Flash, but doesn't work on IE <= 9.
There are several solutions but they depend on HTML5 and haven't been implemented completely in some browsers yet. Examples below were tested in Chrome and Firefox (partly works).
Canvas example with save to file support. Just set your document.location.href to the data URI.
Anchor download example. It uses <a href="your-data-uri" download="filename.txt"> to specify file name.
Combining answers from #owencm and #Chazt3n, this function will allow download of text from IE11, Firefox, and Chrome. (Sorry, I don't have access to Safari or Opera, but please add a comment if you try and it works.)
initiate_user_download = function(file_name, mime_type, text) {
// Anything but IE works here
if (undefined === window.navigator.msSaveOrOpenBlob) {
var e = document.createElement('a');
var href = 'data:' + mime_type + ';charset=utf-8,' + encodeURIComponent(text);
e.setAttribute('href', href);
e.setAttribute('download', file_name);
document.body.appendChild(e);
e.click();
document.body.removeChild(e);
}
// IE-specific code
else {
var charCodeArr = new Array(text.length);
for (var i = 0; i < text.length; ++i) {
var charCode = text.charCodeAt(i);
charCodeArr[i] = charCode;
}
var blob = new Blob([new Uint8Array(charCodeArr)], {type: mime_type});
window.navigator.msSaveOrOpenBlob(blob, file_name);
}
}
// Example:
initiate_user_download('data.csv', 'text/csv', 'Sample,Data,Here\n1,2,3\n');
This can be solved 100% entirely with HTML alone. Just set the href attribute to "data:(mimetypeheader),(url)". For instance...
<a
href="data:video/mp4,http://www.example.com/video.mp4"
target="_blank"
download="video.mp4"
>Download Video</a>
Working example: JSFiddle Demo.
Because we use a Data URL, we are allowed to set the mimetype which indicates the type of data to download. Documentation:
Data URLs are composed of four parts: a prefix (data:), a MIME type indicating the type of data, an optional base64 token if non-textual, and the data itself. (Source: MDN Web Docs: Data URLs.)
Components:
<a ...> : The link tag.
href="data:video/mp4,http://www.example.com/video.mp4" : Here we are setting the link to the a data: with a header preconfigured to video/mp4. This is followed by the header mimetype. I.E., for a .txt file, it would would be text/plain. And then a comma separates it from the link we want to download.
target="_blank" : This indicates a new tab should be opened, it's not essential, but it helps guide the browser to the desired behavior.
download: This is the name of the file you're downloading.
If you only need to actually have a download action, like if you bind it to some button that will generate the URL on the fly when clicked (in Vue or React for example), you can do something as easy as this:
const link = document.createElement('a')
link.href = url
link.click()
In my case, the file is already properly named but you can set it thanks to filename if needed.
For anyone having issues in IE:
dataURItoBlob = function(dataURI) {
var binary = atob(dataURI.split(',')[1]);
var array = [];
for(var i = 0; i < binary.length; i++) {
array.push(binary.charCodeAt(i));
}
return new Blob([new Uint8Array(array)], {type: 'image/png'});
}
var blob = dataURItoBlob(uri);
window.navigator.msSaveOrOpenBlob(blob, "my-image.png");
This code was originally provided by #Yetti on this answer (separate question).
Your problem essentially boils down to "not all browsers will support this".
You could try a workaround and serve the unzipped files from a Flash object, but then you'd lose the JS-only purity (anyway, I'm not sure whether you currently can "drag files into browser" without some sort of Flash workaround - is that a HTML5 feature maybe?)
Coming late to the party, if you'd like to use a function without using the DOM, here it goes, since the DOM might not even be available for whatever reason.
It should be applicable in any Browser which has the fetch API.
Just test it here:
// declare the function
function downloadAsDataURL (url) {
return new Promise((resolve, reject) => {
fetch(url)
.then(res => res.blob())
.then(blob => {
const reader = new FileReader()
reader.readAsDataURL(blob)
reader.onloadend = () => resolve(reader.result)
reader.onerror = err => reject(err)
})
.catch(err => reject(err))
})
}
// simply use it like this
downloadAsDataURL ('https://cdn-icons-png.flaticon.com/512/3404/3404134.png')
.then((res) => {
console.log(res)
})
.catch((err) => {
console.error(err)
})
export const downloadAs = async (url: string, name: string) => {
const blob = await axios.get(url, {
headers: {
'Content-Type': 'application/octet-stream',
},
responseType: 'blob',
});
const a = document.createElement('a');
const href = window.URL.createObjectURL(blob.data);
a.href = href;
a.download = name;
a.click();
};
You can use a clean code solution, inform your url in a constant, and set it as param of open method instead in object window.
const url = "file url here"
window.open(url)
I currently have an ASP.NET Core 2.1 API endpoint that users can hit to download a CSV file:
[HttpPost("Gimme")]
public IActionResult Gimme([FromBody] MyOptions options)
{
MemoryStream reportStream = _reportGenerator.GenerateReportStream(options.StartDate, options.EndDate);
return new FileStreamResult(reportStream, "text/csv") { FileDownloadName = "report.csv" };
}
I can test it via POSTMan and it returns a CSV with the correct data, no problem.
Enter Angular. The web site we're interacting with our API from uses an Angular-Driven Single Page Application. I've searched for various ways on how to handle files coming from API endpoints, and a lot seem to revolve around getting a Blob and creating an inline URL that is then navigated to via window.open() in the JavaScript. Or creating in-memory a tags to then call click() on.
My question: Does the latest Angular really have no way to handle this out of the box? I'm no Angular expert but I would've thought there'd be an example up on their site or some built-in mechanism for serving a downloaded file to the browser. There seems, however, to just be a lot of hackery involved.
My current, WIP solution does return the file to the browser for download, but regardless of the file name specified in the API, it is downloaded as a temporary file name (some GUID-looking thing) instead:
Below is what I have both in my Component and Service classes. I updated the downloadFile() method to use the answer supplied in this SO answer to get friendly file names working, but I would still rather find a less-hacky solution.
// Component
DownloadReport(options: ReportOptions) {
this._service.getCSV(options).subscribe(data => this.downloadFile(data));
}
downloadFile(blob: Blob) {
const fileName = 'report.csv';
if (navigator.msSaveBlob) {
// IE 10+
navigator.msSaveBlob(blob, fileName);
} else {
const link = document.createElement('a');
const url = URL.createObjectURL(blob);
link.setAttribute('href', url);
link.setAttribute('download', fileName);
link.style.visibility = 'hidden';
document.body.appendChild(link);
link.click();
document.body.removeChild(link);
URL.revokeObjectURL(url);
}
}
// Service
getCSV(reportOptions: ReportOptions): Observable<any> {
let headers = new HttpHeaders();
headers = headers.set('Accept', 'text/csv');
return this._httpClient
.post(`${this.apiRoot}/Gimme`, reportOptions, { headers: headers, responseType: 'blob' })
.catch(this.handleError);
}
As you can see, I'm currently implementing the createObjectURL hack to get this working (a mash of Found On Internet solutions). Is there a better way? A "Best Practices" sort of way?
This is what I use. It's basically the same thing you are using, but looks a little cleaner to me with the Anchor typing. I researched the right way to do this for a long time and couldn't find a non-hacky way to do it.
download(): void {
this.service.getFile({ id: id, name: name })
.subscribe(data => {
if (window.navigator && window.navigator.msSaveOrOpenBlob) {
//save file for IE
window.navigator.msSaveOrOpenBlob(data, name);
} else {
const objectUrl: string = URL.createObjectURL(data);
const a: HTMLAnchorElement = document.createElement('a') as HTMLAnchorElement;
a.href = objectUrl;
a.download = name;
document.body.appendChild(a);
a.click();
document.body.removeChild(a);
URL.revokeObjectURL(objectUrl);
}
});
}
I want to download file forcefully. but in new chrome update, file open on browser rather than download in case of Image/Video/Audio/PDF
HTML:
Click to download file
Controller:
$scope.downloadFile = function () {
fileInfo = {
path: collection.file_path,
file_name: collection.file_name
};
payOutService.getSignedUrlFromS3ByPath(fileInfo).success(function (response) {//response is simply file link
var link = document.createElement("a");
link.download = collection.file_name;
link.href = response;
link.click();
}
});
};
Note: For checking this issue you have to update your google chrome(Version 66.0.3359.117 (Official Build) (64-bit)).
How Can I do this. I have checked approximately every response on stackoverflow.com but there is no solution of my issue because it come under new update of chrome. I appreciate every response. Thanks Ahead.
I want to download byte array into file in Internet Explorer and Microsoft Edge using javascript(c#). Anchor.download element is not supported in these browsers.
I have searched a lot and nothing seem to work out. Please help me find a solution.
I have tried Window.location=url.
I have tried solution suggested in following:
Saving binary data as file using JavaScript from a browser the Blob.js and FileSaver.js is not supported and even that is not working.
I need a proper solution where I can download the file with its extension and proper name. I have the data in byte array, I have the name of the file with extension. It is working in Chrome but not in other browsers.
Following is the working code for Chrome :-
var sampleBytes = new Int8Array(responsetext);
var saveByteArray = (function () {
var a = document.createElement("a");
document.body.appendChild(a);
a.style = "display: none";
return function (data, DocName) {
var blob = new Blob(data, { type: "octet/stream" }),
url = window.URL.createObjectURL(blob);
a.href = url;
a.download = DocName;
a.click();
window.URL.revokeObjectURL(url);
};
}());
saveByteArray([sampleBytes],DocName);
I'm playing with the idea of making a completely JavaScript-based zip/unzip utility that anyone can access from a browser. They can just drag their zip directly into the browser and it'll let them download all the files within. They can also create new zip files by dragging individual files in.
I know it'd be better to do it serverside, but this project is just for a bit of fun.
Dragging files into the browser should be easy enough if I take advantage of the various methods available. (Gmail style)
Encoding/decoding should hopefully be fine. I've seen some as3 zip libraries so I'm sure I should be fine with that.
My issue is downloading the files at the end.
window.location = 'data:jpg/image;base64,/9j/4AAQSkZJR....'
this works fine in Firefox but not in Chrome.
I can embed the files as images just fine in chrome using <img src="data:jpg/image;ba.." />, but the files won't necessarily be images. They could be any format.
Can anyone think of another solution or some kind of workaround?
If you also want to give a suggested name to the file (instead of the default 'download') you can use the following in Chrome, Firefox and some IE versions:
function downloadURI(uri, name) {
var link = document.createElement("a");
link.download = name;
link.href = uri;
document.body.appendChild(link);
link.click();
document.body.removeChild(link);
delete link;
}
And the following example shows it's use:
downloadURI("data:text/html,HelloWorld!", "helloWorld.txt");
function download(dataurl, filename) {
const link = document.createElement("a");
link.href = dataurl;
link.download = filename;
link.click();
}
download("data:text/html,HelloWorld!", "helloWorld.txt");
or:
function download(url, filename) {
fetch(url)
.then(response => response.blob())
.then(blob => {
const link = document.createElement("a");
link.href = URL.createObjectURL(blob);
link.download = filename;
link.click();
})
.catch(console.error);
}
download("https://get.geojs.io/v1/ip/geo.json","geoip.json")
download("data:text/html,HelloWorld!", "helloWorld.txt");
Ideas:
Try a <a href="data:...." target="_blank"> (Untested)
Use downloadify instead of data URLs (would work for IE as well)
Want to share my experience and help someone stuck on the downloads not working in Firefox and updated answer to 2014.
The below snippet will work in both firefox and chrome and it will accept a filename:
// Construct the <a> element
var link = document.createElement("a");
link.download = thefilename;
// Construct the uri
var uri = 'data:text/csv;charset=utf-8;base64,' + someb64data
link.href = uri;
document.body.appendChild(link);
link.click();
// Cleanup the DOM
document.body.removeChild(link);
Here is a pure JavaScript solution I tested working in Firefox and Chrome but not in Internet Explorer:
function downloadDataUrlFromJavascript(filename, dataUrl) {
// Construct the 'a' element
var link = document.createElement("a");
link.download = filename;
link.target = "_blank";
// Construct the URI
link.href = dataUrl;
document.body.appendChild(link);
link.click();
// Cleanup the DOM
document.body.removeChild(link);
delete link;
}
Cross-browser solutions found up until now:
downloadify -> Requires Flash
databounce -> Tested in IE 10 and 11, and doesn't work for me. Requires a servlet and some customization. (Incorrectly detects navigator. I had to set IE in compatibility mode to test, default charset in servlet, JavaScript options object with correct servlet path for absolute paths...) For non-IE browsers, it opens the file in the same window.
download.js -> http://danml.com/download.html Another library similar but not tested. Claims to be pure JavaScript, not requiring servlet nor Flash, but doesn't work on IE <= 9.
There are several solutions but they depend on HTML5 and haven't been implemented completely in some browsers yet. Examples below were tested in Chrome and Firefox (partly works).
Canvas example with save to file support. Just set your document.location.href to the data URI.
Anchor download example. It uses <a href="your-data-uri" download="filename.txt"> to specify file name.
Combining answers from #owencm and #Chazt3n, this function will allow download of text from IE11, Firefox, and Chrome. (Sorry, I don't have access to Safari or Opera, but please add a comment if you try and it works.)
initiate_user_download = function(file_name, mime_type, text) {
// Anything but IE works here
if (undefined === window.navigator.msSaveOrOpenBlob) {
var e = document.createElement('a');
var href = 'data:' + mime_type + ';charset=utf-8,' + encodeURIComponent(text);
e.setAttribute('href', href);
e.setAttribute('download', file_name);
document.body.appendChild(e);
e.click();
document.body.removeChild(e);
}
// IE-specific code
else {
var charCodeArr = new Array(text.length);
for (var i = 0; i < text.length; ++i) {
var charCode = text.charCodeAt(i);
charCodeArr[i] = charCode;
}
var blob = new Blob([new Uint8Array(charCodeArr)], {type: mime_type});
window.navigator.msSaveOrOpenBlob(blob, file_name);
}
}
// Example:
initiate_user_download('data.csv', 'text/csv', 'Sample,Data,Here\n1,2,3\n');
This can be solved 100% entirely with HTML alone. Just set the href attribute to "data:(mimetypeheader),(url)". For instance...
<a
href="data:video/mp4,http://www.example.com/video.mp4"
target="_blank"
download="video.mp4"
>Download Video</a>
Working example: JSFiddle Demo.
Because we use a Data URL, we are allowed to set the mimetype which indicates the type of data to download. Documentation:
Data URLs are composed of four parts: a prefix (data:), a MIME type indicating the type of data, an optional base64 token if non-textual, and the data itself. (Source: MDN Web Docs: Data URLs.)
Components:
<a ...> : The link tag.
href="data:video/mp4,http://www.example.com/video.mp4" : Here we are setting the link to the a data: with a header preconfigured to video/mp4. This is followed by the header mimetype. I.E., for a .txt file, it would would be text/plain. And then a comma separates it from the link we want to download.
target="_blank" : This indicates a new tab should be opened, it's not essential, but it helps guide the browser to the desired behavior.
download: This is the name of the file you're downloading.
If you only need to actually have a download action, like if you bind it to some button that will generate the URL on the fly when clicked (in Vue or React for example), you can do something as easy as this:
const link = document.createElement('a')
link.href = url
link.click()
In my case, the file is already properly named but you can set it thanks to filename if needed.
For anyone having issues in IE:
dataURItoBlob = function(dataURI) {
var binary = atob(dataURI.split(',')[1]);
var array = [];
for(var i = 0; i < binary.length; i++) {
array.push(binary.charCodeAt(i));
}
return new Blob([new Uint8Array(array)], {type: 'image/png'});
}
var blob = dataURItoBlob(uri);
window.navigator.msSaveOrOpenBlob(blob, "my-image.png");
This code was originally provided by #Yetti on this answer (separate question).
Your problem essentially boils down to "not all browsers will support this".
You could try a workaround and serve the unzipped files from a Flash object, but then you'd lose the JS-only purity (anyway, I'm not sure whether you currently can "drag files into browser" without some sort of Flash workaround - is that a HTML5 feature maybe?)
Coming late to the party, if you'd like to use a function without using the DOM, here it goes, since the DOM might not even be available for whatever reason.
It should be applicable in any Browser which has the fetch API.
Just test it here:
// declare the function
function downloadAsDataURL (url) {
return new Promise((resolve, reject) => {
fetch(url)
.then(res => res.blob())
.then(blob => {
const reader = new FileReader()
reader.readAsDataURL(blob)
reader.onloadend = () => resolve(reader.result)
reader.onerror = err => reject(err)
})
.catch(err => reject(err))
})
}
// simply use it like this
downloadAsDataURL ('https://cdn-icons-png.flaticon.com/512/3404/3404134.png')
.then((res) => {
console.log(res)
})
.catch((err) => {
console.error(err)
})
export const downloadAs = async (url: string, name: string) => {
const blob = await axios.get(url, {
headers: {
'Content-Type': 'application/octet-stream',
},
responseType: 'blob',
});
const a = document.createElement('a');
const href = window.URL.createObjectURL(blob.data);
a.href = href;
a.download = name;
a.click();
};
You can use a clean code solution, inform your url in a constant, and set it as param of open method instead in object window.
const url = "file url here"
window.open(url)