Manel,
Okay - so my disclaimer is that I don't claim to be overly knowledgeable about
Betwixt. I joined the list to ask some questions about Betwixt and no one
answered me, so I've tried to help anyone that has questions.
Given your input - I'd say that LayerNode "has-a" (array) list, not that
LayerNode "is-a" (array) list. Because LayerNode has attributes (chiefly
'name', and maybe other elements) that make it more than just a subclass of
ArrayList<FieldNode>. (The Head Start Design Patterns book has an example, a
"Bath is-a Tub" doesn't sound right - but a "Bath has-a Tub" does sound right.
I may be wrong here in the view on the containment relation, but I think it
works better)
Now, there is a way to tell the BeanReader that your XML has a collection that
is not wrapped in a "containing" element. Which is your case here. But I'll
get to that after explaining how I've mapped the objects.
This is the approach that I'd try:
LayerNode.betwixt:
------------------
<?xml version='1.0' encoding='UTF-8' ?>
<info primitiveTypes='element'>
<element name='LayerNode'>
<attribute name="name" property="name"/>
<element name="FieldNode" property="nodes" updater="addFieldNode"/>
<addDefaults/>
</element>
</info>
LayerNode.java:
------------------------
public class LayerNode {
private List<FieldNode> nodes = new ArrayList<FieldNode>();
private String name;
public void addFieldNode(FieldNode fnode) {
nodes.add(fnode);
}
/* important - you need to have your getters/setters, I've omitted them
- but I
defined them in accordance with what you'd expect for a bean/pojo */
}
(note - I added 'id' when I was trying to map this without your sample...)
FieldNode.betwixt:
--------------------
<?xml version='1.0' encoding='UTF-8' ?>
<info primitiveTypes='element'>
<hide property='position'/>
<element name='FieldNode'>
<attribute name="id" property="id"/>
<attribute name="name" property="name"/>
<addDefaults/>
</element>
</info>
FieldNode.java:
-------------------
public class FieldNode {
private Long id;
private String name;
private int position;
/* bean/pojo getters/setters omitted */
}
I wrote a little JUnit test to see if it was loading correctly:
public void testDocumentLoad() { // class omitted to save space
try {
LayerNode root = getRootNode("./text.xml");
assertNotNull(root);
} catch (Exception e) {
e.printStackTrace(); System.out.println("exception occured... lame");
}
}
public LayerNode getRootNode(String filename) {
try { // this assumes 'filename' is on the classpath
InputStream xtnodes = getClass().getResourceAsStream(filename);
BeanReader beanReader = new BeanReader();
beanReader.getXMLIntrospector().getConfiguration()
.setWrapCollectionsInElement(false);
beanReader.registerBeanClass(LayerNode.class);
return (LayerNode)beanReader.parse(xtnodes);
} catch (Exception e) {
e.printStackTrace(); System.out.println("exception occured... lame");
return null;
}
}
file: text.xml (file used)
--------------------------------------
<?xml version='1.0' encoding='UTF-8' ?>
<LayerNode name="a">
<FieldNode id="650" name="a1"/>
<FieldNode id="999" name="a2"/>
</LayerNode>
I was able to get LayerNode loaded with the two FieldNode instances,
with their
id and name properties populated.
I've had similar issues in my projects. I found odd things like, the 'name'
attribute of an element wouldn't get automatically mapped to the 'name'
property of the corresponding object. So what I'd do is get something working
- then slowly add to the xml and the object. I still don't feel too
comfortable with Betwixt overall. And it seemed nearly impossible to get help
- so I hope this helps you out.
Andy
/****************************************
* @author: Andrew Lenards
* @email: [EMAIL PROTECTED]
* @title: Systems Programmer, Principal
* @project: Tree of Life Web Project
* @website: http://tolweb.org/
* @dept: Dept. of Entomology
* @school: University of Arizona
* @geo-loc: Tucson, AZ 85721
***************************************/
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