XFA Specification
Chapter 15, Template Specification
Template Reference
618
The ref element
An element holding an XFA-SOM expression that identifies a node to be included in an XML digital
signature.
<ref
Properties:
id="xml-id"
use="cdata"
usehref="cdata"
>
...pcdata...
</ref>
The ref element is used within the following other elements:
manifest proto
The reference must be to a node that is written out to XML when the form is saved. The reference is stored
in the XML digital signature manifest as an XPath expression pointing to the corresponding element in the
XML document. The computed signature includes that element and all of its children.
If the value of this element includes the destination of the signature, the signature handler automatically
excludes the signature from the signature value it calculates.
Examples of SOM expressions used as the value of this element are foo[*] and mySubform..myField
Content
The XFA-SOM expression.
The id property
A unique identifier that may be used to identify this element as a target.
The use property
Invokes another object in the same document as a prototype for this object. The content of this property is
either a SOM expression (which cannot start with '#') or a '#' character followed by an XML ID.
Starting with XFA 2.4 the object used as a prototype no longer needs to be the child of
proto
. Any object
of the appropriate class can be used as a prototype.
If both
use
and
usehref
are non-empty
usehref
takes precedence.
The usehref property
Invokes an external object as a prototype for this object. The content of this property is an URL, followed
by '#', followed by either an XML ID or by som(SOM_expr) where
SOM_expr
represents a SOM expression.
The XML ID or SOM expression is resolved in the context of the external document.
If both
use
and
usehref
are non-empty
usehref
takes precedence.