[jdom-interest] Comment and ProcessingInstruction parents

[Elliotte Rusty Harold]

The Comment and ProcessingInstruction classes appear to be deeply 
schizophrenic about who can be their parents, specifically whether or 
not a Document is allowed as a parent of one of these. (This is legal in 
normal XML temrinology. A typical xml-stylesheet processing instruction 
in the prolog would be considered to have the document itself as its 
parent.)

For example, in ProcessingInstruction the parent field is declared to 
have type Object:

    /** Parent element, document, or null if none */
    protected Object parent;

However, setParent() and getParent() only allow elements as parents:

    /**
     * <p>
     * This will return the parent of this 
<code>ProcessingInstruction</code>.
     *   If there is no parent, then this returns <code>null</code>.
     * </p>
     *
     * @return parent of this <code>ProcessingInstruction</code>
     */
    public Element getParent() {
        if (parent instanceof Element) {
            return (Element) parent;
        }
        return null;
    }

    /**
     * <p>
     * This will set the parent of this <code>ProcessingInstruction</code>.
     * </p>
     *
     * @param parent <code>Element</code> to be new parent.
     * @return this <code>ProcessingInstruction</code> modified.
     */
    protected ProcessingInstruction setParent(Element parent) {
        this.parent = parent;
        return this;
    }

One of these needs to be fixed, and I think it's setParent() and 
getParent(). Processing instructions and comments do appear with the 
document itself as the natural parent. We need to support that.


-- 
+-----------------------+------------------------+-------------------+
| Elliotte Rusty Harold | elharo at metalab.unc.edu | Writer/Programmer |
+-----------------------+------------------------+-------------------+ 
|           The XML Bible, 2nd Edition (IDG Books, 2001)             |
|             http://www.cafeconleche.org/books/bible2/              |
|   http://www.amazon.com/exec/obidos/ISBN=0764547607/cafeaulaitA/   |
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