XFA Specification
Chapter 3, Object Models in XFA
Document Object Models
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<bind dataRef="$record.manual" match="dataRef" />
</subform>
In the second XML sample the order of the
dataRef
and
match
properties has been changed but this is
not significant and is not
necessarily
reflected in the DOM.
Children
Children are nodes that can occur any number of times (including zero). When expressed in XML child
elements can freely interleave with property elements and such interleaving has no significance. However
the order of child nodes with respect to each other is significant. When a DOM is expressed in XML
document order corresponds to a depth-first traversal of the tree. For child nodes document order
corresponds to oldest-to-youngest. By convention oldest-to-youngest is also referred to as left-to-right.
For example, consider the following fragment of XML:
<subform name="book">
<field name="title"> ... </field>
<field name="author"> ... </field>
<field name="publisher"> ... </field>
<field name="ISBN"> ... </field>
</subform>
When the fragment is loaded into the Template DOM the result is as follows:
subform
children
of the
subform
name
“book”
field
field
field
field
property
of the
subform
name
“title”
property
of a field
name
“author”
name
“publisher”
name
“ISBN”
Children in a DOM
The subform object has five nodes below it, one property node and four child nodes. Each of the child
nodes is a field object. There are exactly as many child nodes as are present in the XML. The document
order of the children is exactly as presented in the XML.
Note that a similar hierarchy is used in XDP documents to represent a collection of DOMs in a single
document. However an XDP may contain subtrees that are not represented by a DOM (for example
application-specific data). At the same time some DOMs (such as the Form and Layout DOMs) are never
represented in an XDP. For this reason in an XDP the outermost element tag is
xdp
rather than
xfa
.
The DOMs Used in XFA
This section introduces the individual DOMs and briefly describes each.