Synopsis

This element establishes conditions that are continuously applied to the instance data.

With instance data defined neatly by the instance element, the question remains of how to annotate instance data nodes with properties necessary for forms. Chapter 5, The XForms Model describes these model item properties but, for now, it is sufficient to know that each model item property is represented by an attribute on this element.

The properties are applied through an additional attribute, nodeset, which, not surprisingly, selects a node-set. For each node in the selected node-set, model item properties are initialized according to the corresponding attribute value. If two separate bind elements are configured to set conflicting model item properties on the same node, an error condition will result, preventing the form from operating.