How to save an ajax response in firefox

Question

I need to find a way to write ajax responses to a file. The responses are XML strings, which is more than fine by me.

What I would like to do, is click on something in my webpage, and save the XML that is returned to a file.

But since I know, that Javascript can't access local files by itself, it is also possible to just send the data on to another server, where PHP would take care of this.

Now the place where I'm stuck is the javascript and the interception. I know, that some of this can be done using greaseMonkey in Firefox. If so, how? Thanks!

Edit: Some explaining.

• The script that creates the output is not written by me.
• Yes, I could see the data in Firebug, seeing is one thing. I need to interpret the data
• There are a lot of requests going on here. About 1 every 2 seconds, so copying them by hand isn't an option.

Still, help?

Answer 1

You should provide more details, a link to the target page is best.
Is the page using jQuery?, Some other library?, or custom XMLHttpRequest() calls?

Anyway, a simpler approach may work, try it first...
If the AJAX data is being written to the page, attach a DOMSubtreeModified event listener to the container element. Something like:

document.getElementById ("ContainerID").addEventListener ("DOMSubtreeModified", YourFunction, false);

function YourFunction () {
    //--- Get the target node's inner HTML and send it to our server. 
}

Note that DOMSubtreeModified events work fine in FF and Chrome, the two main browsers for Greasemonkey.

If the data is not being written to the page, then the best way to intercept the AJAX depends on if the target page is using a library like jQuery.

A generic way to intercept AJAX can be seen in this SO question (and others).

As you said, once you have the data, to automatically write it to a file, use GM_xmlhttpRequest() to send it to a server that you control.

Answer 2

Why cannot you do it like this?

Save AJAX response to file on the server side and then provide a link to it, so it can be downloaded.

Answer 3

Firebug will also help, you can view in very convenient way each response in few formats, and eventually copy/save it.

Answer 4

Use a normal (non-AJAX) request and add a Content-Disposition: attachment; filename="foo.xml" header to the response.

Answer 5

If you're just going to save the XML, why are you using AJAX? Just set location.href to the location of a PHP script that sends a "Content-disposition: attachment" header and gives the XML in the response body. AJAX seems totally the wrong tool for the job.