如何从JavaScript更改XML元素值？

Question

I have an XML DB and I have been able to parse the XML using DOM with JS. The thing I am unable to figure out is, how can I change a value in my XML db?

I tried using:

xmlDoc.getElementsByTagName("COMMENT")[0].childNodes[0].nodeValue="text"; 

But this does not changes the actual DB. When I refresh my page, it gives me the same old value again.

What am I doing wrong?

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Edit:

I am making changes only on the client page and not sending the data back to make relevant changes in database itself.

I understand I should use AJAX or something, but could you please give me directions on what I should read or some examples where I can learn?

Answer 1

You cannot write to XML with JavaScript, only load a copy of the XML DOM into memory and manipulate that copy. Obviously that is destroyed when the JS instance restarts (reloading the page) or you re-load from the original file.

If the XML is on the server, you will need a server-side language such as PHP, ASP.NET, Ruby on Rails, etc. to write anything to disk on the server. That code executes on the server, not in the browser.

• Reading and Writing XML in c#
• XML for PHP developers, Part 1
• Ruby on Rails and XML

To communicate between your JavaScript code and your server-side code, AJAX is the answer. A List Apart has a good resource for getting started . The simplest model that comes to mind is using AJAX to send the complete, modified XML chunk to server-side code, which simply saves it.

If you are dealing with huge files and frequent updates, you may want to consider using AJAX to send manipulation instructions to the server-side code, which execute the changes and save the file.

Answer 2

您基本上没有告诉我们任何相关信息，但是很可能您只是在更改客户端页面，并且不做任何努力（例如使用表单或AJAX）发回更改。

Answer 3

You need to save db after changes. It is not possible with DOM and JS on Web Browser, so you should use AJAX or sth similar to process XML