The constraint Property
Release 2.0 - ...
Specifies a predicate that needs to be satisfied for the associated instance data node to be considered valid.
| Computed Expression | Yes |
| Legal Values | Any expression that is convertible to XPath boolean with boolean(). |
| Default Value | true() |
| Inheritance Rules | does not inherit. |
When evaluating to XPath false, the associated model item is not valid; the converse is not necessarily true. This model item property does not prevent form controls and XForms actions from setting invalid values into data nodes.
Example
| XML |
Copy Code
|
|---|---|
<xforms:bind nodeset="/range/to" constraint="number(.) > number(/range/from)"/> |
|
Specification
Link to the XForms specification: the constraint Property.