I would like to know if there is any way to generate a text/xml file in javascript. I want users to be able to fill out a page form when they are offline, save the data, and then use the saved file at a later point in time. The browser will be IE, most likely IE7.
Thanks
The files should be stored on client filesystems, right?
In general, saving data on client's computer by a web script would be considered a security breach. I would avoid doing so but if it's one of your project requirements, you can give it a try.
Since the target platform would be IE, you can try ActiveX. Example code (not tested):
var fso = new ActiveXObject("Scripting.FileSystemObject");
var fh = fso.CreateTextFile("c:\\path\\file.txt", true);
fh.WriteLine("Some text");
fh.Close();
You might have to use Flash in order to access the user's filesystem to save the file. That is the way most client-side components work if they need to create a file wholly on the client.
Time to learn ActionScript, and say goodbye to iDevices compatibility!
Related
I'm trying to write to a local file using javascript and html on a mac. I've seen forums saying you could use ActiveXObject, but that is only on windows using IE right?
You can not access local file system using Javascript. But if want to store a Javascript variable, then you can look into LocalStorage.
http://diveintohtml5.info/storage.html
If HTML5 is a valid option for you, you can use the new filesystem API. Take a look at this introduction: http://www.noupe.com/webdev/html5-filesystem-api-create-files-store-locally-using-javascript-webkit.html
Security limitations don't allow javascript to access the local file system through the browser.
But you can use the Node.js interpreter to run javascript "server side".
If this is the case, your code should look something like this.
yes ,there is a way to save file,but not in local system,because of some security reasons browser's don't allow to save local files,but there are many ways by that you can save file in client side system!
The most common if you using HTML5 then localstorage.setItem('yourfilename',fileasblob);
Create a blob of file that you want to store,and save it on localstorage by its name!
example :
var filedata = "......yourfilecontent.....";
var locfile = new Blob([filedata],{content-type});
localstorage.setItem('newfile.txt',locfile); //for save
var mylocfile = localstorage.getItem('newfile.txt');
var locfilesrc = URL.createObjectURL(mylocfile);//retrive as temporary URL for any use!
by this way you can save any file on local storage,And the main thing is that this storage is not deleted until you can not clear it by your own!
So I've been researching this for a couple days and haven't come up with anything conclusive. I'm trying to create a (very) rudimentary liveblogging setup because I don't want to pay for something like CoverItLive. My process is: Local HTML file > Cloud storage (Dropbox/Drive/etc) > iframe on content page. All that works, and with some CSS even looks pretty nice despite the less-than-awesome approach. But here's the thing: the liveblog itself is made up of an HTML table, and I have to manually copy/paste the code for a new row, fill in the timestamp, write the new message, and save the document (which then syncs with the cloud and shows up in the iframe). To simplify the process I've made another HTML file which I intend to run locally and use to add entries to the table automatically. At the moment it's just a bunch of input boxes and some javascript to automate the timestamp and write the table row from the input data.
Code, as it stands now: http://jsfiddle.net/LukeLC/999bH/
What I'm looking to do from here is find a way to somehow export the generated table data to another .html file on my hard drive. So far I've managed to get this code...
if(document.documentElement && document.documentElement.innerHTML){
var a=document.getElementById("tblive").innerHTML;
a=a.replace(/</g,'<');
var w=window.open();
w.document.open();
w.document.write('<pre><tblive>\n'+a+'\n</tblive></pre>');
w.document.close();
}
}
...to open just the generated table code in a new window, and sure, I can save the source from there, but the whole point is to eliminate steps like that from the process.
How can I tell the page to save the generated code to a separate .html file when I click on the 'submit' button? Again, all of this happens locally, not on a server.
I'm not very good with javascript--and maybe a different language will be necessary--but any help is much appreciated.
I suppose you could do something like this:
var myHTMLDoc = "<html><head><title>mydoc</title></head><body>This is a test page</body></html>";
var uri = "data:application/octet-stream;base64,"+btoa(myHTMLDoc);
document.location = uri;
BTW, btoa might not be cross-browser, I think modern browsers all have it, but older versions of IE don't. AFAIK base64 isn't even needed. you might be able to get away with
var uri = "data:application/octet-stream,"+myHTMLDoc;
Drawbacks with this is that you can't set the filename when it gets saved
You cant do this with javascript but you can have a HTML5 link to open save dialogue:
<a href="pageToDownload.html" download>Download</a>
You could add some smarts to automate it on the processed page after the POST.
fiddle : http://jsfiddle.net/ghQ9M/
Simple answer, you can't.
JavaScript is restricted to perform such operations due to security reasons.
The best way to accomplish that, would be, to call a server page that would write
the new file on the server. Then from javascript perform a POST request to the
server page passing the data you want to write to the new file.
If you want the user to save the page to it's file system, this is a different
problem and the best approach to accomplish that, would be to, notify the user/ask him
to save the page, that page could be your new window like you are doing w.open().
Let me do some demonstration for you:
//assuming you know jquery or are willing to use it :)
var html = $("#tblive").html().replace(/</g, '<');
//generating your download button
$.post('generate_page.php', { content: html })
.done(function( data ) {
var filename = data;
//inject some html to allow user to navigate to the new page (example)
$('#tblive').parent().append(
'Check your Dynamic Page!');
// you data here, is the response from the server so you can return
// your new dynamic page file name here.
// and maybe to some window.location="new page";
});
On the server side, something like this:
<?php
if($_REQUEST["content"]){
$pagename = uniqid("page_", true) . '.html';
file_put_contents($pagename, $_REQUEST["content"]);
echo $pagename;
}
?>
Some notes, I haven't tested the example, but it works in theory.
I assume that with this the effort to implement it should be minimal, assuming this solves your problem.
A server based solution:
You'll need to set up a server (or your PC) to serve your HTML page with headers that tell your browser to download the page instead of processing the HTML markup. If you want to do this on your local machine, you can use software such as WAMP (or MAMP for Mac or LAMP for Linux) that is basically a web server in a .exe. It's a lot of hassle but it'll work.
This question already has answers here:
Create and save a file with JavaScript [duplicate]
(11 answers)
Closed 7 years ago.
I have a situation where I need to give my users the option to save some data stored locally in their client memory to disk. The current workaround I have is having a handler like this
(define-handler (download-deck) ((deck :json))
(setf (header-out :content-type) "application/json"
(header-out :content-disposition) "attachment")
deck)
which does exactly what it looks like. The client sends their data up, and saves the returned file locally.
This seems stupid.
Please, please tell me there's a better, simpler, cross-browser way to let a client save some local data to their disk with a file-save dialog box.
Every answer I read on the subject either says "no, you can't save files with javascript" or "yes, there's this one semi-documented piece of the Chrome API that might let you do it in three pages".
This "FileSaver" library may help. If you want it to be reasonably cross-browser, you'll also need this to implement the W3C Blob API in places it's not already implemented. Both respect namespaces, and are completely framework agnostic, so don't worry about naming issues.
Once you've got those included, and as long as you're only saving text files, you should be able to
var blob = new Blob(["Hello, world!"], {type: "text/plain;charset=utf-8"});
saveAs(blob, "hello world.txt");
Note that the first argument to new Blob has to be a list of strings, and that you're expected to specify the filename. As in, the user will see this file being downloaded locally, but won't be able to name it themselves. Hopefully they're using a browser that handles local filename collisions...
This is my code:
<a id='tfa_src_data'>Export</a>
document.getElementById('tfa_src_data').onclick = function() {
var csv = JSON.stringify(localStorage['savedCoords']);
var csvData = 'data:application/csv;charset=utf-8,'
+ encodeURIComponent(csv);
this.href = csvData;
this.target = '_blank';
this.download = 'filename.txt';
};
You can use various data types.
Depending on what you are trying to do exactly, the HTML5 local storage concept might help you.
So what is HTML5 Storage? Simply put, it’s a way for web pages to store named key/value pairs locally, within the client web browser. Like cookies, this data persists even after you navigate away from the web site, close your browser tab, exit your browser, or what have you. Unlike cookies, this data is never transmitted to the remote web server (unless you go out of your way to send it manually). http://diveintohtml5.info/storage.html
There's also the Filesystem API (so far only implemented in Chrome AFAIK)
http://www.html5rocks.com/en/tutorials/file/filesystem/
I'm not able to save to the xml file on my machine.
I have noticed that node value is changed temprorily but not permanent in xml file.
P.S : This is only a simple HTML file with javascript
It is giving me an error "Permission Denied"
function viewBookDetails() {
var xmlDoc = xmlLoader("cart.xml");
//var x = xmlDoc.getElementsByTagName("dogHouse")[0];
var x = xmlDoc.documentElement;
var newel = xmlDoc.createElement("essy");
x.appendChild(newel);
alert(x.xml);
xmlDoc.save("cart.xml");
}
is it not possible to save xml file on my machine?
Thank you,
In general, browser JavaScript has no I/O API and cannot read or write to the client filesystem since that could be a security loophole. I haven't seen or used the save() method before but it looks like it's an IE specific extension to the XML DOM. If you must use it, this thread might provide the solution, the answer that worked for the OP there suggested:
I haven't proofed your code but here is something you might want to try. I am taking a shot in the dark that you are using this on a Windows OS since you are using IE and from the sound of the error. Just take your html file that you have and rename it the whatever.hta and it will then be able to write to the xml file and save.
Also, the documentation for the method says the following for when the argument is a string (as in your code snippet):
String
Specifies the file name. This must be a file name rather than a URL. The file is created, if necessary, and the contents are replaced entirely with the contents of the saved document. This mode is not intended for use from a secure client, such as Microsoft Internet Explorer.
From the forum posts (links below) that deal with the same issue, I gleaned the following:
This is an IE specific extension and so will only work in IE
There are obviously security restrictions in place so you shouldn't be able to do this 'out of the box'
One workaround that crops up often is to rename the file extension to .hta (Hypertext Application) instead of .html
I'm not sure but there might also be some workarounds by changing the permissions for the security zones your application runs in
References:
http://www.codingforums.com/showthread.php?t=25048
http://p2p.wrox.com/xml/4053-error-using-xml-save-method.html
http://www.daniweb.com/web-development/javascript-dhtml-ajax/threads/204995
I'd like to make an XML document in JavaScript then have a save dialog appear.
It's OK if they have to click before the save can occur.
It's *not* OK if I *have* to use IE to achieve this (I don't even need to support it at all). However, Windows is a required platform (so Firefox or Chrome are the preferred browsers if I can only do this in one browser).
It's *not* OK if I need a web server. But conversely, I don't want to require the JavaScript to be run on a local file only, i.e. elevated privileges -- if possible. That is, I'd like to to run locally or on a *static* host. But just locally is OK.
It's OK to have to bend over backwards to do this. The file won't be very big, but internet access might either be there, be spotty or just not be a possibility at all -- see (3).
So far the only ideas I have seen are to save the XML to an iframe and save that document -- but it seems that you can only do this in IE? Also, that I could construct a data URI and place that in a link. My fear here is that it will just open the XML file in the window, rather than prompt the user to save it.
I know that if I require the JavaScript to be local, I can raise privileges and just directly save the file (or hopefully cause a save dialog box to appear). However, I'd much prefer a solution where I do not require raised privileges (even a Firefox 3.6 only solution).
I apologize if this offends anyone's sensibilities (for example, not supporting every browser). I basically want to write an offline application and Javascript/HTML/CSS seem to be the best candidate considering the complexity of the requirements and the time available. However, I have this single requirement of being able to save data that must be overcome before I can choose this line of development.
How about this downloadify script?
Which is based on Flash and jQuery, which can prompt you dialog box to save file in your computer.
Downloadify.create('downloadify',{
filename: function(){
return document.getElementById('filename').value;
},
data: function(){
return document.getElementById('data').value;
},
onComplete: function(){
alert('Your File Has Been Saved!');
},
onCancel: function(){
alert('You have cancelled the saving of this file.');
},
onError: function(){
alert('You must put something in the File Contents or there will be nothing to save!');
},
swf: 'media/downloadify.swf',
downloadImage: 'images/download.png',
width: 100,
height: 30,
transparent: true,
append: false
});
Using a base64 encoded data URI, this is possible with only html & js. What you can do is encode the data that you want to save (in your case, a string of XML data) into base64, using a js library like jquery-base64 by carlo. Then put the encoded string into a link, and add your link to the DOM.
Example using the library I mentioned (as well as jquery):
<html>
<head>
<title>Example</title>
</head>
<body>
<script>
//include jquery and jquery-base64 here (or whatever library you want to use)
document.write('click to make save dialog');
</script>
</body>
</html>
...and remember to make the content-type something like application/octet-stream so the browser doesn't try to open it.
Warning: some older IE versions don't support base64, but you said that didn't matter, so this should work fine for you.
Without any more insight into your specific requirements, I would not recommend a pure Javascript/HTML solution. From a user perspective you would probably get the best results writing a native application. However if it will be faster to use Javascript/HTML, I recommend using a local application hosting a lightweight web server to serve up your content. That way you can cleanly handle the file saving server-side while focusing the bulk of your effort on the front-end application.
You can code up a web server in - for example - Python or Ruby using very few lines of code and without 3rd party libraries. For example, see:
Making a simple web server in python
WEBrick - Writing a custom servlet
python-trick-really-little-http-server - This one is really simple, and will easily let you server up all of your HTML/CSS/JS files:
"""
Serves files out of its current directory.
Doesn't handle POST requests.
"""
import SocketServer
import SimpleHTTPServer
PORT = 8080
def move():
""" sample function to be called via a URL"""
return 'hi'
class CustomHandler(SimpleHTTPServer.SimpleHTTPRequestHandler):
def do_GET(self):
#Sample values in self for URL: http://localhost:8080/jsxmlrpc-0.3/
#self.path '/jsxmlrpc-0.3/'
#self.raw_requestline 'GET /jsxmlrpc-0.3/ HTTP/1.1rn'
#self.client_address ('127.0.0.1', 3727)
if self.path=='/move':
#This URL will trigger our sample function and send what it returns back to the browser
self.send_response(200)
self.send_header('Content-type','text/html')
self.end_headers()
self.wfile.write(move()) #call sample function here
return
else:
#serve files, and directory listings by following self.path from
#current working directory
SimpleHTTPServer.SimpleHTTPRequestHandler.do_GET(self)
httpd = SocketServer.ThreadingTCPServer(('localhost', PORT),CustomHandler)
print "serving at port", PORT
httpd.serve_forever()
Finally - Depending on who will be using your application, you also have the option of compiling a Python program into a Frozen Binary so the end user does not have to have Python installed on their machine.
Javascript is not allowed to write to a local machine. Your question is similar to this one.
I suggest creating a simple desktop app.
Is localhost PHP server ok? Web traditionally can't save to hard drive because of security concerns. PHP can push files though it requires a server.
Print to PDF plugins are available for available for all browsers. Install once, print to PDF forever. Then, you can use a javascript or Flash to call a Print function.
Also, if you are developing for an environment where internet access is spotty, conwider using VB.NET or some other desktop language.
EDIT:
You can use the browser's Print function.
Are you looking for something like this?
If PHP is ok, if would be much easier.
With IE you could use document.execCommand, but I note that IE is not an option.
Here's something that looks like it might help, although it will not prompt with SaveAs dialog, https://developer.mozilla.org/en/Code_snippets/File_I%2F%2FOL.
One simple but odd way to do this that doesn't require any Flash is to create an <a/> with a data URI for its href. This even has pretty good cross-browser support, although for IE it must be at least version 8 and the URI must be < 32k. It looks like someone else on SO has more to say on the topic.
Why not use a hybrid flash for client and some server solution server-side. Most people have flash so you can default to client side to conserve resources on the server.