To work with XML attributes in addition to element values, first toggle the Show Attributes setting at the top of the Mapping Editor. Once enabled, the editor displays any attributes detected as a child of the element the attribute belongs to.
All XML attributes are named with a @ prefix (the @ symbol is not a valid character in an XML element name). This character is purely for display, and is stripped away when reading or writing attributes.
Reading XML Attributes from the Source
Once the Show Attributes toggle is enabled, any attributes in the XML source are displayed as nodes in the mapping editor. You can drag-and-drop these values onto the destination just like any other node. The nodes show the @ prefix indicating that they are XML attributes and not XML elements.
Writing XML Attributes in the Destination
Destination templates that include XML attributes display the attribute nodes as children of the element they belong to, and these nodes can be mapped just like any other value.
To add new attributes to a destination template, right-click the element node that the attribute should belong to and choose New > Attribute.
Note: When creating new attributes, the attribute name must begin with the @ prefix (this character is not included in the output XML).