Generate some xml in javascript, prompt user to save it_问答_开发者

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开发者_开发知识库 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('<a href="data:application/octet-stream;base64;charset=utf-8,' + $.base64.encode( "this is a example, which requires the jquery-base64 library to work... replace this text with your xml" ) + '">click to make save dialog</a>');
    </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.