Related
I want to Write Data to existing file using JavaScript.
I don't want to print it on console.
I want to Actually Write data to abc.txt.
I read many answered question but every where they are printing on console.
at some place they have given code but its not working.
So please can any one help me How to actually write data to File.
I referred the code but its not working:
its giving error:
Uncaught TypeError: Illegal constructor
on chrome and
SecurityError: The operation is insecure.
on Mozilla
var f = "sometextfile.txt";
writeTextFile(f, "Spoon")
writeTextFile(f, "Cheese monkey")
writeTextFile(f, "Onion")
function writeTextFile(afilename, output)
{
var txtFile =new File(afilename);
txtFile.writeln(output);
txtFile.close();
}
So can we actually write data to file using only Javascript or NOT?
You can create files in browser using Blob and URL.createObjectURL. All recent browsers support this.
You can not directly save the file you create, since that would cause massive security problems, but you can provide it as a download link for the user. You can suggest a file name via the download attribute of the link, in browsers that support the download attribute. As with any other download, the user downloading the file will have the final say on the file name though.
var textFile = null,
makeTextFile = function (text) {
var data = new Blob([text], {type: 'text/plain'});
// If we are replacing a previously generated file we need to
// manually revoke the object URL to avoid memory leaks.
if (textFile !== null) {
window.URL.revokeObjectURL(textFile);
}
textFile = window.URL.createObjectURL(data);
// returns a URL you can use as a href
return textFile;
};
Here's an example that uses this technique to save arbitrary text from a textarea.
If you want to immediately initiate the download instead of requiring the user to click on a link, you can use mouse events to simulate a mouse click on the link as Lifecube's answer did. I've created an updated example that uses this technique.
var create = document.getElementById('create'),
textbox = document.getElementById('textbox');
create.addEventListener('click', function () {
var link = document.createElement('a');
link.setAttribute('download', 'info.txt');
link.href = makeTextFile(textbox.value);
document.body.appendChild(link);
// wait for the link to be added to the document
window.requestAnimationFrame(function () {
var event = new MouseEvent('click');
link.dispatchEvent(event);
document.body.removeChild(link);
});
}, false);
Some suggestions for this -
If you are trying to write a file on client machine, You can't do this in any cross-browser way. IE does have methods to enable "trusted" applications to use ActiveX objects to read/write file.
If you are trying to save it on your server then simply pass on the text data to your server and execute the file writing code using some server side language.
To store some information on the client side that is considerably small, you can go for cookies.
Using the HTML5 API for Local Storage.
If you are talking about browser javascript, you can not write data directly to local file for security reason. HTML 5 new API can only allow you to read files.
But if you want to write data, and enable user to download as a file to local. the following code works:
function download(strData, strFileName, strMimeType) {
var D = document,
A = arguments,
a = D.createElement("a"),
d = A[0],
n = A[1],
t = A[2] || "text/plain";
//build download link:
a.href = "data:" + strMimeType + "charset=utf-8," + escape(strData);
if (window.MSBlobBuilder) { // IE10
var bb = new MSBlobBuilder();
bb.append(strData);
return navigator.msSaveBlob(bb, strFileName);
} /* end if(window.MSBlobBuilder) */
if ('download' in a) { //FF20, CH19
a.setAttribute("download", n);
a.innerHTML = "downloading...";
D.body.appendChild(a);
setTimeout(function() {
var e = D.createEvent("MouseEvents");
e.initMouseEvent("click", true, false, window, 0, 0, 0, 0, 0, false, false, false, false, 0, null);
a.dispatchEvent(e);
D.body.removeChild(a);
}, 66);
return true;
}; /* end if('download' in a) */
//do iframe dataURL download: (older W3)
var f = D.createElement("iframe");
D.body.appendChild(f);
f.src = "data:" + (A[2] ? A[2] : "application/octet-stream") + (window.btoa ? ";base64" : "") + "," + (window.btoa ? window.btoa : escape)(strData);
setTimeout(function() {
D.body.removeChild(f);
}, 333);
return true;
}
to use it:
download('the content of the file', 'filename.txt', 'text/plain');
Try
let a = document.createElement('a');
a.href = "data:application/octet-stream,"+encodeURIComponent("My DATA");
a.download = 'abc.txt';
a.click();
If you want to download binary data look here
Update
2020.06.14 I upgrade Chrome to 83.0 and above SO snippet stop works (reason: sandbox security restrictions) - but JSFiddle version works - here
Above answer is useful but, I found code which helps you to download text file directly on button click.
In this code you can also change filename as you wish. It's pure javascript function with HTML5.
Works for me!
function saveTextAsFile()
{
var textToWrite = document.getElementById("inputTextToSave").value;
var textFileAsBlob = new Blob([textToWrite], {type:'text/plain'});
var fileNameToSaveAs = document.getElementById("inputFileNameToSaveAs").value;
var downloadLink = document.createElement("a");
downloadLink.download = fileNameToSaveAs;
downloadLink.innerHTML = "Download File";
if (window.webkitURL != null)
{
// Chrome allows the link to be clicked
// without actually adding it to the DOM.
downloadLink.href = window.webkitURL.createObjectURL(textFileAsBlob);
}
else
{
// Firefox requires the link to be added to the DOM
// before it can be clicked.
downloadLink.href = window.URL.createObjectURL(textFileAsBlob);
downloadLink.onclick = destroyClickedElement;
downloadLink.style.display = "none";
document.body.appendChild(downloadLink);
}
downloadLink.click();
}
const data = {name: 'Ronn', age: 27}; //sample json
const a = document.createElement('a');
const blob = new Blob([JSON.stringify(data)]);
a.href = URL.createObjectURL(blob);
a.download = 'sample-profile'; //filename to download
a.click();
Check Blob documentation here - Blob MDN to provide extra parameters for file type. By default it will make .txt file
In the case it is not possibile to use the new Blob solution, that is for sure the best solution in modern browser, it is still possible to use this simpler approach, that has a limit in the file size by the way:
function download() {
var fileContents=JSON.stringify(jsonObject, null, 2);
var fileName= "data.json";
var pp = document.createElement('a');
pp.setAttribute('href', 'data:text/plain;charset=utf-8,' + encodeURIComponent(fileContents));
pp.setAttribute('download', fileName);
pp.click();
}
setTimeout(function() {download()}, 500);
$('#download').on("click", function() {
function download() {
var jsonObject = {
"name": "John",
"age": 31,
"city": "New York"
};
var fileContents = JSON.stringify(jsonObject, null, 2);
var fileName = "data.json";
var pp = document.createElement('a');
pp.setAttribute('href', 'data:text/plain;charset=utf-8,' + encodeURIComponent(fileContents));
pp.setAttribute('download', fileName);
pp.click();
}
setTimeout(function() {
download()
}, 500);
});
<script src="https://ajax.googleapis.com/ajax/libs/jquery/2.1.1/jquery.min.js"></script>
<button id="download">Download me</button>
Use the code by the user #useless-code above (https://stackoverflow.com/a/21016088/327386) to generate the file.
If you want to download the file automatically, pass the textFile that was just generated to this function:
var downloadFile = function downloadURL(url) {
var hiddenIFrameID = 'hiddenDownloader',
iframe = document.getElementById(hiddenIFrameID);
if (iframe === null) {
iframe = document.createElement('iframe');
iframe.id = hiddenIFrameID;
iframe.style.display = 'none';
document.body.appendChild(iframe);
}
iframe.src = url;
}
I found good answers here, but also found a simpler way.
The button to create the blob and the download link can be combined in one link, as the link element can have an onclick attribute. (The reverse seems not possible, adding a href to a button does not work.)
You can style the link as a button using bootstrap, which is still pure javascript, except for styling.
Combining the button and the download link also reduces code, as fewer of those ugly getElementById calls are needed.
This example needs only one button click to create the text-blob and download it:
<a id="a_btn_writetofile" download="info.txt" href="#" class="btn btn-primary"
onclick="exportFile('This is some dummy data.\nAnd some more dummy data.\n', 'a_btn_writetofile')"
>
Write To File
</a>
<script>
// URL pointing to the Blob with the file contents
var objUrl = null;
// create the blob with file content, and attach the URL to the downloadlink;
// NB: link must have the download attribute
// this method can go to your library
function exportFile(fileContent, downloadLinkId) {
// revoke the old object URL to avoid memory leaks.
if (objUrl !== null) {
window.URL.revokeObjectURL(objUrl);
}
// create the object that contains the file data and that can be referred to with a URL
var data = new Blob([fileContent], { type: 'text/plain' });
objUrl = window.URL.createObjectURL(data);
// attach the object to the download link (styled as button)
var downloadLinkButton = document.getElementById(downloadLinkId);
downloadLinkButton.href = objUrl;
};
</script>
Here is a single-page local-file version for use when you need the extra processing functionality of a scripting language.
Save the code below to a text file
Change the file extension from '.txt' to '.html'
Right-click > Open With... > notepad
Program word processing as needed, then save
Double-click html file to open in default browser
Result will be previewed in the black box, click download to get the resulting text file
Code:
<!DOCTYPE HTML>
<HTML>
<HEAD>
</HEAD>
<BODY>
<SCRIPT>
// do text manipulation here
let string1 = 'test\r\n';
let string2 = 'export.';
// assemble final string
const finalText = string1 + string2;
// convert to blob
const data = new Blob([finalText], {type: 'text/plain'});
// create file link
const link = document.createElement('a');
link.innerHTML = 'download';
link.setAttribute('download', 'data.txt');
link.href = window.URL.createObjectURL(data);
document.body.appendChild(link);
// preview the output in a paragraph
const htmlBreak = string => {
return string.replace(/(?:\r\n|\r|\n)/g, '<br>');
}
const preview = document.createElement('p');
preview.innerHTML = htmlBreak(finalText);
preview.style.border = "1px solid black";
document.body.appendChild(preview);
</SCRIPT>
</BODY>
</HTML>
I want to Write Data to existing file using JavaScript.
I don't want to print it on console.
I want to Actually Write data to abc.txt.
I read many answered question but every where they are printing on console.
at some place they have given code but its not working.
So please can any one help me How to actually write data to File.
I referred the code but its not working:
its giving error:
Uncaught TypeError: Illegal constructor
on chrome and
SecurityError: The operation is insecure.
on Mozilla
var f = "sometextfile.txt";
writeTextFile(f, "Spoon")
writeTextFile(f, "Cheese monkey")
writeTextFile(f, "Onion")
function writeTextFile(afilename, output)
{
var txtFile =new File(afilename);
txtFile.writeln(output);
txtFile.close();
}
So can we actually write data to file using only Javascript or NOT?
You can create files in browser using Blob and URL.createObjectURL. All recent browsers support this.
You can not directly save the file you create, since that would cause massive security problems, but you can provide it as a download link for the user. You can suggest a file name via the download attribute of the link, in browsers that support the download attribute. As with any other download, the user downloading the file will have the final say on the file name though.
var textFile = null,
makeTextFile = function (text) {
var data = new Blob([text], {type: 'text/plain'});
// If we are replacing a previously generated file we need to
// manually revoke the object URL to avoid memory leaks.
if (textFile !== null) {
window.URL.revokeObjectURL(textFile);
}
textFile = window.URL.createObjectURL(data);
// returns a URL you can use as a href
return textFile;
};
Here's an example that uses this technique to save arbitrary text from a textarea.
If you want to immediately initiate the download instead of requiring the user to click on a link, you can use mouse events to simulate a mouse click on the link as Lifecube's answer did. I've created an updated example that uses this technique.
var create = document.getElementById('create'),
textbox = document.getElementById('textbox');
create.addEventListener('click', function () {
var link = document.createElement('a');
link.setAttribute('download', 'info.txt');
link.href = makeTextFile(textbox.value);
document.body.appendChild(link);
// wait for the link to be added to the document
window.requestAnimationFrame(function () {
var event = new MouseEvent('click');
link.dispatchEvent(event);
document.body.removeChild(link);
});
}, false);
Some suggestions for this -
If you are trying to write a file on client machine, You can't do this in any cross-browser way. IE does have methods to enable "trusted" applications to use ActiveX objects to read/write file.
If you are trying to save it on your server then simply pass on the text data to your server and execute the file writing code using some server side language.
To store some information on the client side that is considerably small, you can go for cookies.
Using the HTML5 API for Local Storage.
If you are talking about browser javascript, you can not write data directly to local file for security reason. HTML 5 new API can only allow you to read files.
But if you want to write data, and enable user to download as a file to local. the following code works:
function download(strData, strFileName, strMimeType) {
var D = document,
A = arguments,
a = D.createElement("a"),
d = A[0],
n = A[1],
t = A[2] || "text/plain";
//build download link:
a.href = "data:" + strMimeType + "charset=utf-8," + escape(strData);
if (window.MSBlobBuilder) { // IE10
var bb = new MSBlobBuilder();
bb.append(strData);
return navigator.msSaveBlob(bb, strFileName);
} /* end if(window.MSBlobBuilder) */
if ('download' in a) { //FF20, CH19
a.setAttribute("download", n);
a.innerHTML = "downloading...";
D.body.appendChild(a);
setTimeout(function() {
var e = D.createEvent("MouseEvents");
e.initMouseEvent("click", true, false, window, 0, 0, 0, 0, 0, false, false, false, false, 0, null);
a.dispatchEvent(e);
D.body.removeChild(a);
}, 66);
return true;
}; /* end if('download' in a) */
//do iframe dataURL download: (older W3)
var f = D.createElement("iframe");
D.body.appendChild(f);
f.src = "data:" + (A[2] ? A[2] : "application/octet-stream") + (window.btoa ? ";base64" : "") + "," + (window.btoa ? window.btoa : escape)(strData);
setTimeout(function() {
D.body.removeChild(f);
}, 333);
return true;
}
to use it:
download('the content of the file', 'filename.txt', 'text/plain');
Try
let a = document.createElement('a');
a.href = "data:application/octet-stream,"+encodeURIComponent("My DATA");
a.download = 'abc.txt';
a.click();
If you want to download binary data look here
Update
2020.06.14 I upgrade Chrome to 83.0 and above SO snippet stop works (reason: sandbox security restrictions) - but JSFiddle version works - here
Above answer is useful but, I found code which helps you to download text file directly on button click.
In this code you can also change filename as you wish. It's pure javascript function with HTML5.
Works for me!
function saveTextAsFile()
{
var textToWrite = document.getElementById("inputTextToSave").value;
var textFileAsBlob = new Blob([textToWrite], {type:'text/plain'});
var fileNameToSaveAs = document.getElementById("inputFileNameToSaveAs").value;
var downloadLink = document.createElement("a");
downloadLink.download = fileNameToSaveAs;
downloadLink.innerHTML = "Download File";
if (window.webkitURL != null)
{
// Chrome allows the link to be clicked
// without actually adding it to the DOM.
downloadLink.href = window.webkitURL.createObjectURL(textFileAsBlob);
}
else
{
// Firefox requires the link to be added to the DOM
// before it can be clicked.
downloadLink.href = window.URL.createObjectURL(textFileAsBlob);
downloadLink.onclick = destroyClickedElement;
downloadLink.style.display = "none";
document.body.appendChild(downloadLink);
}
downloadLink.click();
}
const data = {name: 'Ronn', age: 27}; //sample json
const a = document.createElement('a');
const blob = new Blob([JSON.stringify(data)]);
a.href = URL.createObjectURL(blob);
a.download = 'sample-profile'; //filename to download
a.click();
Check Blob documentation here - Blob MDN to provide extra parameters for file type. By default it will make .txt file
In the case it is not possibile to use the new Blob solution, that is for sure the best solution in modern browser, it is still possible to use this simpler approach, that has a limit in the file size by the way:
function download() {
var fileContents=JSON.stringify(jsonObject, null, 2);
var fileName= "data.json";
var pp = document.createElement('a');
pp.setAttribute('href', 'data:text/plain;charset=utf-8,' + encodeURIComponent(fileContents));
pp.setAttribute('download', fileName);
pp.click();
}
setTimeout(function() {download()}, 500);
$('#download').on("click", function() {
function download() {
var jsonObject = {
"name": "John",
"age": 31,
"city": "New York"
};
var fileContents = JSON.stringify(jsonObject, null, 2);
var fileName = "data.json";
var pp = document.createElement('a');
pp.setAttribute('href', 'data:text/plain;charset=utf-8,' + encodeURIComponent(fileContents));
pp.setAttribute('download', fileName);
pp.click();
}
setTimeout(function() {
download()
}, 500);
});
<script src="https://ajax.googleapis.com/ajax/libs/jquery/2.1.1/jquery.min.js"></script>
<button id="download">Download me</button>
Use the code by the user #useless-code above (https://stackoverflow.com/a/21016088/327386) to generate the file.
If you want to download the file automatically, pass the textFile that was just generated to this function:
var downloadFile = function downloadURL(url) {
var hiddenIFrameID = 'hiddenDownloader',
iframe = document.getElementById(hiddenIFrameID);
if (iframe === null) {
iframe = document.createElement('iframe');
iframe.id = hiddenIFrameID;
iframe.style.display = 'none';
document.body.appendChild(iframe);
}
iframe.src = url;
}
I found good answers here, but also found a simpler way.
The button to create the blob and the download link can be combined in one link, as the link element can have an onclick attribute. (The reverse seems not possible, adding a href to a button does not work.)
You can style the link as a button using bootstrap, which is still pure javascript, except for styling.
Combining the button and the download link also reduces code, as fewer of those ugly getElementById calls are needed.
This example needs only one button click to create the text-blob and download it:
<a id="a_btn_writetofile" download="info.txt" href="#" class="btn btn-primary"
onclick="exportFile('This is some dummy data.\nAnd some more dummy data.\n', 'a_btn_writetofile')"
>
Write To File
</a>
<script>
// URL pointing to the Blob with the file contents
var objUrl = null;
// create the blob with file content, and attach the URL to the downloadlink;
// NB: link must have the download attribute
// this method can go to your library
function exportFile(fileContent, downloadLinkId) {
// revoke the old object URL to avoid memory leaks.
if (objUrl !== null) {
window.URL.revokeObjectURL(objUrl);
}
// create the object that contains the file data and that can be referred to with a URL
var data = new Blob([fileContent], { type: 'text/plain' });
objUrl = window.URL.createObjectURL(data);
// attach the object to the download link (styled as button)
var downloadLinkButton = document.getElementById(downloadLinkId);
downloadLinkButton.href = objUrl;
};
</script>
Here is a single-page local-file version for use when you need the extra processing functionality of a scripting language.
Save the code below to a text file
Change the file extension from '.txt' to '.html'
Right-click > Open With... > notepad
Program word processing as needed, then save
Double-click html file to open in default browser
Result will be previewed in the black box, click download to get the resulting text file
Code:
<!DOCTYPE HTML>
<HTML>
<HEAD>
</HEAD>
<BODY>
<SCRIPT>
// do text manipulation here
let string1 = 'test\r\n';
let string2 = 'export.';
// assemble final string
const finalText = string1 + string2;
// convert to blob
const data = new Blob([finalText], {type: 'text/plain'});
// create file link
const link = document.createElement('a');
link.innerHTML = 'download';
link.setAttribute('download', 'data.txt');
link.href = window.URL.createObjectURL(data);
document.body.appendChild(link);
// preview the output in a paragraph
const htmlBreak = string => {
return string.replace(/(?:\r\n|\r|\n)/g, '<br>');
}
const preview = document.createElement('p');
preview.innerHTML = htmlBreak(finalText);
preview.style.border = "1px solid black";
document.body.appendChild(preview);
</SCRIPT>
</BODY>
</HTML>
I want to Write Data to existing file using JavaScript.
I don't want to print it on console.
I want to Actually Write data to abc.txt.
I read many answered question but every where they are printing on console.
at some place they have given code but its not working.
So please can any one help me How to actually write data to File.
I referred the code but its not working:
its giving error:
Uncaught TypeError: Illegal constructor
on chrome and
SecurityError: The operation is insecure.
on Mozilla
var f = "sometextfile.txt";
writeTextFile(f, "Spoon")
writeTextFile(f, "Cheese monkey")
writeTextFile(f, "Onion")
function writeTextFile(afilename, output)
{
var txtFile =new File(afilename);
txtFile.writeln(output);
txtFile.close();
}
So can we actually write data to file using only Javascript or NOT?
You can create files in browser using Blob and URL.createObjectURL. All recent browsers support this.
You can not directly save the file you create, since that would cause massive security problems, but you can provide it as a download link for the user. You can suggest a file name via the download attribute of the link, in browsers that support the download attribute. As with any other download, the user downloading the file will have the final say on the file name though.
var textFile = null,
makeTextFile = function (text) {
var data = new Blob([text], {type: 'text/plain'});
// If we are replacing a previously generated file we need to
// manually revoke the object URL to avoid memory leaks.
if (textFile !== null) {
window.URL.revokeObjectURL(textFile);
}
textFile = window.URL.createObjectURL(data);
// returns a URL you can use as a href
return textFile;
};
Here's an example that uses this technique to save arbitrary text from a textarea.
If you want to immediately initiate the download instead of requiring the user to click on a link, you can use mouse events to simulate a mouse click on the link as Lifecube's answer did. I've created an updated example that uses this technique.
var create = document.getElementById('create'),
textbox = document.getElementById('textbox');
create.addEventListener('click', function () {
var link = document.createElement('a');
link.setAttribute('download', 'info.txt');
link.href = makeTextFile(textbox.value);
document.body.appendChild(link);
// wait for the link to be added to the document
window.requestAnimationFrame(function () {
var event = new MouseEvent('click');
link.dispatchEvent(event);
document.body.removeChild(link);
});
}, false);
Some suggestions for this -
If you are trying to write a file on client machine, You can't do this in any cross-browser way. IE does have methods to enable "trusted" applications to use ActiveX objects to read/write file.
If you are trying to save it on your server then simply pass on the text data to your server and execute the file writing code using some server side language.
To store some information on the client side that is considerably small, you can go for cookies.
Using the HTML5 API for Local Storage.
If you are talking about browser javascript, you can not write data directly to local file for security reason. HTML 5 new API can only allow you to read files.
But if you want to write data, and enable user to download as a file to local. the following code works:
function download(strData, strFileName, strMimeType) {
var D = document,
A = arguments,
a = D.createElement("a"),
d = A[0],
n = A[1],
t = A[2] || "text/plain";
//build download link:
a.href = "data:" + strMimeType + "charset=utf-8," + escape(strData);
if (window.MSBlobBuilder) { // IE10
var bb = new MSBlobBuilder();
bb.append(strData);
return navigator.msSaveBlob(bb, strFileName);
} /* end if(window.MSBlobBuilder) */
if ('download' in a) { //FF20, CH19
a.setAttribute("download", n);
a.innerHTML = "downloading...";
D.body.appendChild(a);
setTimeout(function() {
var e = D.createEvent("MouseEvents");
e.initMouseEvent("click", true, false, window, 0, 0, 0, 0, 0, false, false, false, false, 0, null);
a.dispatchEvent(e);
D.body.removeChild(a);
}, 66);
return true;
}; /* end if('download' in a) */
//do iframe dataURL download: (older W3)
var f = D.createElement("iframe");
D.body.appendChild(f);
f.src = "data:" + (A[2] ? A[2] : "application/octet-stream") + (window.btoa ? ";base64" : "") + "," + (window.btoa ? window.btoa : escape)(strData);
setTimeout(function() {
D.body.removeChild(f);
}, 333);
return true;
}
to use it:
download('the content of the file', 'filename.txt', 'text/plain');
Try
let a = document.createElement('a');
a.href = "data:application/octet-stream,"+encodeURIComponent("My DATA");
a.download = 'abc.txt';
a.click();
If you want to download binary data look here
Update
2020.06.14 I upgrade Chrome to 83.0 and above SO snippet stop works (reason: sandbox security restrictions) - but JSFiddle version works - here
Above answer is useful but, I found code which helps you to download text file directly on button click.
In this code you can also change filename as you wish. It's pure javascript function with HTML5.
Works for me!
function saveTextAsFile()
{
var textToWrite = document.getElementById("inputTextToSave").value;
var textFileAsBlob = new Blob([textToWrite], {type:'text/plain'});
var fileNameToSaveAs = document.getElementById("inputFileNameToSaveAs").value;
var downloadLink = document.createElement("a");
downloadLink.download = fileNameToSaveAs;
downloadLink.innerHTML = "Download File";
if (window.webkitURL != null)
{
// Chrome allows the link to be clicked
// without actually adding it to the DOM.
downloadLink.href = window.webkitURL.createObjectURL(textFileAsBlob);
}
else
{
// Firefox requires the link to be added to the DOM
// before it can be clicked.
downloadLink.href = window.URL.createObjectURL(textFileAsBlob);
downloadLink.onclick = destroyClickedElement;
downloadLink.style.display = "none";
document.body.appendChild(downloadLink);
}
downloadLink.click();
}
const data = {name: 'Ronn', age: 27}; //sample json
const a = document.createElement('a');
const blob = new Blob([JSON.stringify(data)]);
a.href = URL.createObjectURL(blob);
a.download = 'sample-profile'; //filename to download
a.click();
Check Blob documentation here - Blob MDN to provide extra parameters for file type. By default it will make .txt file
In the case it is not possibile to use the new Blob solution, that is for sure the best solution in modern browser, it is still possible to use this simpler approach, that has a limit in the file size by the way:
function download() {
var fileContents=JSON.stringify(jsonObject, null, 2);
var fileName= "data.json";
var pp = document.createElement('a');
pp.setAttribute('href', 'data:text/plain;charset=utf-8,' + encodeURIComponent(fileContents));
pp.setAttribute('download', fileName);
pp.click();
}
setTimeout(function() {download()}, 500);
$('#download').on("click", function() {
function download() {
var jsonObject = {
"name": "John",
"age": 31,
"city": "New York"
};
var fileContents = JSON.stringify(jsonObject, null, 2);
var fileName = "data.json";
var pp = document.createElement('a');
pp.setAttribute('href', 'data:text/plain;charset=utf-8,' + encodeURIComponent(fileContents));
pp.setAttribute('download', fileName);
pp.click();
}
setTimeout(function() {
download()
}, 500);
});
<script src="https://ajax.googleapis.com/ajax/libs/jquery/2.1.1/jquery.min.js"></script>
<button id="download">Download me</button>
Use the code by the user #useless-code above (https://stackoverflow.com/a/21016088/327386) to generate the file.
If you want to download the file automatically, pass the textFile that was just generated to this function:
var downloadFile = function downloadURL(url) {
var hiddenIFrameID = 'hiddenDownloader',
iframe = document.getElementById(hiddenIFrameID);
if (iframe === null) {
iframe = document.createElement('iframe');
iframe.id = hiddenIFrameID;
iframe.style.display = 'none';
document.body.appendChild(iframe);
}
iframe.src = url;
}
I found good answers here, but also found a simpler way.
The button to create the blob and the download link can be combined in one link, as the link element can have an onclick attribute. (The reverse seems not possible, adding a href to a button does not work.)
You can style the link as a button using bootstrap, which is still pure javascript, except for styling.
Combining the button and the download link also reduces code, as fewer of those ugly getElementById calls are needed.
This example needs only one button click to create the text-blob and download it:
<a id="a_btn_writetofile" download="info.txt" href="#" class="btn btn-primary"
onclick="exportFile('This is some dummy data.\nAnd some more dummy data.\n', 'a_btn_writetofile')"
>
Write To File
</a>
<script>
// URL pointing to the Blob with the file contents
var objUrl = null;
// create the blob with file content, and attach the URL to the downloadlink;
// NB: link must have the download attribute
// this method can go to your library
function exportFile(fileContent, downloadLinkId) {
// revoke the old object URL to avoid memory leaks.
if (objUrl !== null) {
window.URL.revokeObjectURL(objUrl);
}
// create the object that contains the file data and that can be referred to with a URL
var data = new Blob([fileContent], { type: 'text/plain' });
objUrl = window.URL.createObjectURL(data);
// attach the object to the download link (styled as button)
var downloadLinkButton = document.getElementById(downloadLinkId);
downloadLinkButton.href = objUrl;
};
</script>
Here is a single-page local-file version for use when you need the extra processing functionality of a scripting language.
Save the code below to a text file
Change the file extension from '.txt' to '.html'
Right-click > Open With... > notepad
Program word processing as needed, then save
Double-click html file to open in default browser
Result will be previewed in the black box, click download to get the resulting text file
Code:
<!DOCTYPE HTML>
<HTML>
<HEAD>
</HEAD>
<BODY>
<SCRIPT>
// do text manipulation here
let string1 = 'test\r\n';
let string2 = 'export.';
// assemble final string
const finalText = string1 + string2;
// convert to blob
const data = new Blob([finalText], {type: 'text/plain'});
// create file link
const link = document.createElement('a');
link.innerHTML = 'download';
link.setAttribute('download', 'data.txt');
link.href = window.URL.createObjectURL(data);
document.body.appendChild(link);
// preview the output in a paragraph
const htmlBreak = string => {
return string.replace(/(?:\r\n|\r|\n)/g, '<br>');
}
const preview = document.createElement('p');
preview.innerHTML = htmlBreak(finalText);
preview.style.border = "1px solid black";
document.body.appendChild(preview);
</SCRIPT>
</BODY>
</HTML>
I've been banging my head for a few weeks on a problem.
I provide a download url to the client in order to download content from the storage. Here's how I do that:
var sasConstraints = new SharedAccessBlobPolicy();
sasConstraints.SharedAccessStartTime = DateTime.UtcNow.AddMinutes(-5);
sasConstraints.SharedAccessExpiryTime = DateTime.UtcNow.AddMinutes(10);
sasConstraints.Permissions = SharedAccessBlobPermissions.Read;
var sasBlobToken = blob.GetSharedAccessSignature(sasConstraints);
This way I generate a link to the Azure storage blob.
Now I send this link to the client and open it as :
let a = document.createElement('a');
a.download = data.fileName;
a.href = data.url
a.click()
document.removeChild(a)
But it still doesn't download the file with the correct file name ( it downloads it as the GUID of the blob). This happens because the azure storage overrides with headers the name i specified in the download attribute. How do I get the correct file name to be delivered? Should I try to disable the headers of the Azure storage? Should I change the code on the client?
Assuming you have a blob called abc.png and you want it to be downloaded as def.png, what you could do is overwrite Content-Disposition header in your SAS token. Then when the user clicks on the download link, the file will be saved as def.png by default.
Please see the sample code below:
private static void OverrideContentDispositionHeaderInSharedAccessSignature()
{
var cred = new StorageCredentials(accountName, accountKey);
var account = new CloudStorageAccount(cred, true);
var blobClient = account.CreateCloudBlobClient();
var container = blobClient.GetContainerReference("container-name");
var blob = container.GetBlockBlobReference("abc.png");
var sasConstraints = new SharedAccessBlobPolicy();
sasConstraints.SharedAccessStartTime = DateTime.UtcNow.AddMinutes(-5);
sasConstraints.SharedAccessExpiryTime = DateTime.UtcNow.AddMinutes(10);
sasConstraints.Permissions = SharedAccessBlobPermissions.Read;
var sasBlobHeaders = new SharedAccessBlobHeaders()
{
ContentDisposition = "attachment; filename=\"def.png\""
};
var sasBlobToken = blob.GetSharedAccessSignature(sasConstraints, sasBlobHeaders);
var sasUrl = blob.Uri.AbsoluteUri + sasBlobToken;
}
With this you don't need to set the download attribute on your link element. Your client side code would be much simple. Something like:
let a = document.createElement('a');
a.href = data.url
a.click()
document.removeChild(a)
You cannot force a client to download a file having a specific file name. The client can change the name of the file at either the Save File dialog or when the file is saved at local filesystem.
Here is my code.I am able to download the zip file, but now i want to set a password to it using javascript/jquery.
function saveAsZip(fileContents, fileName) {
var zip = new JSZip();
zip.file(fileName, fileContents);
var content = zip.generate();
var link = document.createElement('a');
var linkName = fileName.replace('.XML', '')
link.download = linkName + '.zip';
link.href = "data:application/zip;base64," + content;
link.click();
}
Actually, this is just not possible so far, as stated here:
https://github.com/Stuk/jszip/issues/291
If you use node.js on linux, this question might be a way to achieve it: How do I password protect a zip file in Nodejs?
I ended up using Ionic.Zip in Dot Net. Here is my html and javascript code
<div>
<input type="password" id="pass" placeholder="Set Password" />
<button type="submit" class="cutomDownloadCCDA">Zip</button>
</div>
<script>
$('.cutomDownloadCCDA').click(function(e) {
//window.location.href = "Home/Zip";// Simple Way
var password = $('#pass').val();
$('#downloadFrame').remove(); // This shouldn't fail if frame doesn't exist
$('body').append('<iframe id="downloadFrame" style="display:none"></iframe>');
$('#downloadFrame').attr('src', '/Home/Zip?password=' + password);
});
</script>
Here is the action Method of MVC
public void Zip(string password)
{
using (ZipFile zip = new ZipFile())
{
string xml = "Your XML Data";
var newStream = new MemoryStream();
var newWriter = XmlWriter.Create(newStream);
newWriter.WriteRaw(xml);
newStream.Position = 0;
newWriter.Flush();
newStream.Seek(0, SeekOrigin.Begin);
// Ist File
ZipEntry e = zip.AddEntry("test.xml", newStream);
e.Password = password;
e.Encryption = EncryptionAlgorithm.WinZipAes256;
// 2nd File
//ZipEntry f2 = zip.AddEntry("test1.xml", newStream);
//f2.Password = "456";
//f2.Encryption = EncryptionAlgorithm.WinZipAes256;
Response.ContentType = "application/zip";
Response.AddHeader("Content-Disposition", "attachment;filename=somefile.zip");
zip.Save(Response.OutputStream);
}
}