Demo Product DocumentationSoftQuad Inc.<Anchor
Id="SDK3"/>Element OverviewIntroduction to ElementsBy far the vast majority of objects (apart from text) that authors
encounter when traversing a document are Element nodes. <Anchor Id="SDK273"/>Element Interfaces<Anchor Id="SDK274"/>Elements and
Attributes<Anchor Id="SDK279"/>Introduction to Attributes
Elements may have attributes associated with them; since the Element
interface inherits from Node, the generic Node interface method
getAttributes may be used to retrieve the set of all
attributes for an element. There are methods on the Element interface to retrieve either an Attr
object by name or an attribute value by name. In XML, where an attribute value
may contain entity references, an Attr object should be retrieved to examine
the possibly fairly complex sub-tree representing the attribute value. On the
other hand, in HTML, where all attributes have simple string values, methods to
directly access an attribute value can safely be used as a convenience. Before you can access an Attribute, you must first gain access to the
associated Element.<Anchor Id="SDK378"/>Setting the Attribute
ValuesAttr objects inherit the Node interface, but since they are not actually
child nodes of the element they describe, the DOM does not consider them part
of the document tree. Thus, the Node attributes parentNode, previousSibling,
and nextSibling have a null value for Attr objects. The DOM takes the view that
attributes are properties of elements rather than having a separate identity
from the elements they are associated with; this should make it more efficient
to implement such features as default attributes associated with all elements
of a given type. Furthermore, Attr nodes may not be immediate children of a
DocumentFragment. However, they can be associated with Element nodes contained
within a DocumentFragment. In short, users and implementors of the DOM need to
be aware that Attr nodes have some things in common with other objects
inheriting the Node interface, but they also are quite distinct. The attribute's effective value is determined as follows:If this attribute has been explicitly assigned any value, that value is
the attribute's effective valueOtherwise, if there is a declaration for this attribute, and that
declaration includes a default value, then that default value is the
attribute's effective valueOtherwise, the attribute does not exist on this element in the structure
model until it has been explicitly added.In XML, where the value of an attribute can contain entity references,
the child nodes of the Attr node provide a representation in which entity
references are not expanded. These child nodes may be either Text or
EntityReference nodes. Because the attribute type may be unknown, there are no
tokenized attribute values. The following topics describe DOM attributes: Interface
Attr
Interface Element<Anchor
Id="SDK48"/>DOM Level 1 Core: Element FunctionssetAttribute
setAttributeSets the Attributes on the associated Element objectFundamental
<Anchor Id="SDK85"/>SyntaxOMG IDLvoidsetAttribute (in
DOMStringname, in DOMStringvalue) raises (DOMException);
<Anchor Id="SDK86"/>Javapublic voidsetAttribute (
Stringname, Stringvalue) throws (DOMException);
<Anchor Id="SDK87"/>ECMA Script
setAttribute (name, value
)
<Anchor Id="SDK88"/>Parametersname(IN) The name of the attribute to create or alter.value(IN) Value to set in string form<Anchor Id="SDK89"/>Exceptions
These are the applicable exceptions. INVALID_CHARACTER_ERRRaised if the specified name contains an invalid character. NO_MODIFICATION_ALLOWED_ERRRaised if this node is readonly.<Anchor
Id="SDK90"/>RemarkssetAttribute adds a new attribute. If an attribute
with that name is already present in the element, its value is changed to be
that of the value parameter. This value is a simple string, it is not parsed as
it is being set. So any markup (such as syntax to be recognized as an entity
reference) is treated as literal text, and needs to be appropriately escaped by
the implementation when it is written out. In order to assign an attribute value that contains entity references,
the user must create an Attr node plus any Text and EntityReference nodes,
build the appropriate subtree, and use setAttributeNode to
assign it as the value of an attribute.
