6
Using Acrobat JavaScript in Forms
Forms Essentials
The XFA DOM model contains a root object that consists of either a
treeList
or a
Tree
.
A
treeList
consists of a list of nodes (which is why it is sometimes called a
NodeList
).
A
Tree
consists of a hierarchical structure of nodes, each of which may contain content, a
model, or a
textNode
.
The following properties and methods are available in a
treeList
object:
Properties:
length
Methods:
append
,
insert
,
item
,
namedItem
, and
remove
.
The following properties and methods are available in a
Tree
object:
Properties:
all
,
classAll
,
classIndex
,
index
,
name
,
nodes
,
parent
,
somExpression
Methods:
resolveNode
,
resolveNodes
Each
Node
element represents an element and its children in the XML DOM. To obtain a
string representation of the node, invoke its
saveXML
method. To apply an XSL transform
(XSLT) to the node and its children, invoke its
applyXSL
method. The following properties
and methods are available in a
Node
object:
Properties:
id
,
isContainer
,
isNull
,
model
,
ns
,
oneOfChild
Methods:
applyXSL
,
assignNode
,
clone
,
getAttribute
,
getElement
,
isPropertySpecified
,
loadXML
,
saveXML
,
setAttribute
,
setElement
There are two approaches to accessing content in an XML stream. In the first approach, XFA
syntax may be used to manipulate the XML DOM. In the second approach, you may use
standard XPath syntax.
The Acrobat JavaScript
XML
object provides two methods useful for manipulating XML
documents:
applyXPath
and
parse
.
The
applyXPath
permits the manipulation of an XML document via an XPath, and the
parse
method creates an object representing an XML document tree. Both of these return
an
XFA
object.
The first approach involves the usage of the
XFL
object’s
parse
method for accessing and
manipulating XML streams. The second approach involves the usage of the
XFL
object’s
applyXPath
method.
Both approaches are illustrated below.
112
Acrobat JavaScript Scripting Guide