106185 - DOM Element has non-null nodeValue attribute

Status: RESOLVED INCOMPLETE

(Core Graveyard :: Java APIs for DOM, defect)

Description

[M. Epstein]

Not sure whether this problem is in the DOM implementation or the Java wrapper 
for it, but it clearly states in the DOM Level 2 Core Spec. that calling 
getNodeValue() on an Element should return null. I've been working with form 
elements and it seems that getNodeValue() returns the current value for INPUT 
elements. I don't particularly have a problem with this, but technically it 
doesn't comply with the DOM, and, more importantly, it is not clearly stated in 
the API or sample code (as far as I can tell), that this is the way to get the 
current value of a text field in a form. After struggling with 
textfield.getAttribute("value"), I learned from a newsgroup that this will 
always supply the default value. This article (http://groups.google.com/groups?
hl=en&threadm=8r91o3%24eq91%40secnews.netscape.com&rnum=1&prev=/groups%3Fq%
3Dmozilla%2Bdom%2Bform%2Bvalue%26hl%3Den%26group%3Dnetscape.public.mozilla.java%
26rnum%3D1%26selm%3D8r91o3%2524eq91%2540secnews.netscape.com) also implies that 
the proper way to get the current value is to cast the element to 
HTMLInputElement and call that interface's getValue() method. The Java DOM for 
Mozilla doesn't seem to have this interface, and after looking through the code 
for org.mozilla.webclient.test.DOMAccessPanel it became clear that calling 
getNodeValue() was the way to get the value. I understand time and resource 
constraints may prevent full compatibility with DOM Level 2, but shouldn't 
something like this be clearly documented somewhere?

A related issue concerns TEXTAREA elements. The value of a TEXTAREA should be 
contained in a TEXT node inside of it, but using the DOMViewer that is part of 
the sample application that comes with the Webclient, it is possible to set the 
text by typing it into the value field or by adding a TEXT node as a child of 
the TEXTAREA (as it should be). What's troubling is that it is possible to add 
different values using both of these methods.

Did I miss an explanation of these inconsistencies somewhere or are they not 
documented?

Comment 1

[Boris Zbarsky [:bzbarsky]]

we _are_ talking about Java, not JavaScript, right?

Comment 2

[M. Epstein]

That is correct. I am referring to Java classes in the packages under
org.mozilla
Most of the classes I use directly are in org.mozilla.webclient, but I
suspect the DOM implementation is backed by classes in org.mozilla.dom. The
problem may not even lie in these classes--it could be in the native Mozilla
DOM implementation.

Comment 3

[Boris Zbarsky [:bzbarsky]]

OK.  The proper way to get the current value of a form element is:

element.getValue()

This is not the same as element.getAttribute("value"), as you pointed out.

Doesn't really affect this bug, but thought I'd let you know.  :)