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 wanted to be able to paste an image from the clipboard into IPython.
Being new to Python, but having solved this problem before in web-apps, I hacked a solution using JavaScript after spending a lot of time poking around in Firefox's inspector.
I found window.IPython and used trial-and-error to guess at which functions to avoid too much DOM hacking. I tried looking for documentation for the JS API but couldn't find anything.
Is there documentation for the IPython/Jupyter JS API somewhere?
Code FYI. Draft only but good enough for me. Use in your own notebooks at your own peril:
%%javascript
// remove the paste listener if it already exists
if (window.paste_listener)
{
window.removeEventListener('paste',window.paste_listener);
}
// (re)declare the paste listener
window.paste_listener = function(event)
{
if (event instanceof ClipboardEvent)
{
var file = event.clipboardData.items[0].getAsFile();
if (file && file.type.substr(0,6) == "image/")
{
var reader = new FileReader();
reader.onloadend = function() {
var cell = IPython.notebook.insert_cell_below('code');
cell.set_text("%%html\n<img src='" + reader.result + "' />");
cell.execute();
};
reader.readAsDataURL(file);
}
}
}
// and add it
window.addEventListener('paste', window.paste_listener);
I'm trying to add an autocomplete feature in my Google Spreadsheet using this Google Apps Script suggest box library from Romain Vialard and James Ferreira's book:
function doGet() {
// Get a list of all my Contacts
var contacts = ContactsApp.getContacts();
var list = [];
for(var i = 0; i < contacts.length; i++){
var emails = contacts[i].getEmails();
if(emails[0] != undefined){
list.push(emails[0].getAddress());
}
}
var app = UiApp.createApplication();
var suggestBox = SuggestBoxCreator.createSuggestBox(app, 'contactPicker', 200, list);
app.add(suggestBox);
return app;
}
function onEdit() {
var s = SpreadsheetApp.getActiveSheet();
if( s.getName() == "my_sheet_name" ) { //checks that we're on the correct sheet
var r = s.getActiveCell();
if( r.getColumn() == 1) {
doGet();
}
}
}
But when I start editing the column 1 of "my_sheet_name" nothing hapens (if I replace doGet() for other function, this other function runs Ok). I've already installed the Suggest Box library. So, why the doGet() function doesn't work?
small confusion here...
The doGet() ..... return app; structure that you are using here is for standalone webapps that need to be deployed and run with their own url in a browser window.
What you are trying to do is to show a Ui in a popup window in a spreadsheet, the mechanism is different : see example below and have a look at the documentation here.
function doGet_or_any_other_name_preferably_something_more_specific() {
var contacts = ContactsApp.getContacts();
var list = [];
for(var i = 0; i < contacts.length; i++){
var emails = contacts[i].getEmails();
if(emails[0] != undefined){
list.push(emails[0].getAddress());
}
}
var app = UiApp.createApplication();
var suggestBox = SuggestBoxCreator.createSuggestBox(app, 'contactPicker', 200, list);
app.add(suggestBox);
SpreadsheetApp.getActive().show(app);
}
Note that this code will allow the Ui to show up but that's about all.... no data will be written in the spreadsheet since you didn't implement any handler to handle the data return. For details about that step read the aforementioned documentation and the examples shown on Romain's website.
EDIT following your comment : tested with this exact code (copied/pasted) and working, see capture below.
I was hunting for an implementations of YUI AutoComplete and I came across this script from the site asklaila.com -
<script type="text/JavaScript">
YAHOO.example.ACJson = new function() {
this.oACDS = new YAHOO.widget.DS_XHR("/AutoComplete.do",
["Suggestions[0].Results","Name"]);
this.oACDS.queryMatchContains = true;
this.oACDS.scriptQueryAppend = "city=Mysore"; // Needed for YWS
function fnCallback(e, args) {
document.searchForm.where.focus();
acSelected = true;
return false;
}
this.oAutoComp = new YAHOO.widget.AutoComplete('what','whatContainer', this.oACDS);
this.oAutoComp.itemSelectEvent.subscribe(fnCallback);
this.oAutoComp.formatResult = function (oResultItem,sQuery) {
return oResultItem[0];
}
this.oAutoComp.queryDelay = 0;
this.oAutoComp.useIFrame = true;
this.oAutoComp.prehighlightClassName = "yui-ac-prehighlight";
this.oAutoComp.minQueryLength = 2;
this.oAutoComp.autoHighlight = false;
this.oAutoComp.textboxFocusEvent.subscribe(function() {
this.oAutoComp.sendQuery("");
});
this.oAutoComp.doBeforeExpandContainer = function(oTextbox, oContainer, sQuery, aResults) {
var pos = YAHOO.util.Dom.getXY(oTextbox);
pos[1] += YAHOO.util.Dom.get(oTextbox).offsetHeight + 2;
YAHOO.util.Dom.setXY(oContainer,pos);
return true;
};
}
</script>
It is implenting the YUI AutoComplete Dropdown. What I want to understand is what this
this.oACDS = new YAHOO.widget.DS_XHR("/AutoComplete.do", ["Suggestions[0].Results","Name"]);
does and its effects on code.
That's using an older version of YUI, but it is setting up a DataSource for the autocomplete to read from. This particular DataSource uses XHR to request information from the server to populate the autocomplete field.
"Autocomplete.do"
Is a relative URL that is being queried by the DataSource every time the autocomplete fires while the user is typing.
["Suggestions[0].Results","Name"]
Is the responseSchema that tells the DataSource how to parse the results from the request to the URL. It needs to know how to parse the data so that it can show the proper results.
this.oACDS = new YAHOO.widget.DS_XHR("/AutoComplete.do", ["Suggestions[0].Results","Name"]);
On every key press, it fetches a json response from the server, and uses it to populate the autocomplete dropdown. The json contains names to display only at this node, "Suggestions[0].Results" in the "name" field.
If you have any trouble, ask ahead. I wrote that piece of code for asklaila.com
I was hunting for implementations of
YUI Autocomplete and I came across
this script...
Why not take a look at YUI AutoComplete page for in-depth examples.
Yahoo! UI Library: AutoComplete