OX Mapping attributes

Question

Hi,
Could someone tell me how to map the value from an object attribute to a xml attribute when using 10.1.3 to perform ObjectXML.
I am able to get my XML Unmarshalled, make changes and Marshal it, but it appears the tag attributes are not coming through
eg
i get
<phone-number>12345</phone-number>
<phone-number>67890</phone-number>
and i want
<phone-number type="home">12345</phone-number>
<phone-number type="work">67890</phone-number>
how do i do it?
Thanks

Answer 1

Hi Martyn,
Mapping an object attribute to XML attribute is similar to mapping an object attribute to an XML text node. The difference is in the XPath specified. To indicate an XML attribute append an "@" to the attribute name when specifying the XPath (see the code example below).
XMLDescriptor desc = new XMLDescriptor();
desc.setJavaClass(PhoneNumber.class);
desc.setDefaultRootElement("phone-number");
XMLDirectMapping typeMapping = new XMLDirectMapping();
typeMapping.setAttributeName("type");
typeMapping.setXPath("@type");
desc.addMapping(typeMapping);
XMLDirectMapping numberMapping = new XMLDirectMapping();
numberMapping.setAttributeName("number");
numberMapping.setXPath("text()");
desc.addMapping(numberMapping);This mapping can also be created in the TopLink Mapping Workbench by selecting the XML attribute using the XPath Chooser GUI.
If your mapping is correct and you are still not seeing the attribute when you marshal the object to XML there are 2 possible causes:
1. You have marked the mapping as read only. In this case TopLink will read the attribute value during the unmarshal operation but will not write the attribute value during the marshal operation.
2. The corresponding value in the object model is null, null values in the object model are not written out when the object is marshalled to XML.
-Blaise