PBDOM_ELEMENT

The PBDOM_ELEMENT represents an XML element modeled in PowerScript. The PBDOM_ELEMENT methods allow access to element attributes, children, and text.

In addition to the methods inherited from PBDOM_OBJECT, the PBDOM_ELEMENT class has the following methods:

• AddNamespaceDeclaration and RemoveNamespaceDeclaration to add namespace declarations to and remove them from the PBDOM_ELEMENT

• GetAttribute, GetAttributes, GetAttributeValue, HasAttributes, RemoveAttribute, SetAttribute, and SetAttributes to manipulate the attributes of the PBDOM_ELEMENT

• GetChildElement, GetChildElements, HasChildElements, RemoveChildElement, and RemoveChildElements to manipulate the children of the PBDOM_ELEMENT

• GetNamespacePrefix and GetNamespaceURI to get the prefix and URI of the namespace associated with the PBDOM_ELEMENT

• GetQualifiedName to get the full name of the PBDOM_ELEMENT including the prefix (if any)

• SetDocument to set a PBDOM_DOCUMENT as the parent of the PBDOM_ELEMENT

• SetNamespace to set the namespace of the PBDOM_ELEMENT

• SetText to set the text content of the PBDOM_ELEMENT

In PBDOM, an XML element's attributes are not its children. They are properties of elements rather than having a separate identity from the elements they are associated with.

Consider the following simple XML document :

<root attr="value1">
   <child attr_1="value1" attr_2="value2"/>
</root>

The solid line joining root with child represents a parent-child relationship. The dashed lines represent a "property-of" relationship between an attribute and its owner element.

The PBDOM_ELEMENT content management methods do not apply to PBDOM_ATTRIBUTE objects. There are separate get, set, and remove methods for attributes.

Because they are not children of their owner elements, PBDOM does not consider attributes as part of the overall PBDOM document tree, but they are linked to it through their owner elements.

An attribute can contain child objects (XML text and entity reference nodes), so an attribute forms a subtree of its own.

In PBDOM, an XML element's attribute is set using the PBDOM_ELEMENT SetAttribute and SetAttributes methods. These methods always attempt to create new attributes for the PBDOM_ELEMENT and attempt to replace existing attributes with the same name and namespace URI.

If the PBDOM_ELEMENT already contains an existing attribute with the same name and namespace URI, these methods first remove the existing attribute and then insert a new attribute into the PBDOM_ELEMENT. Calling the SetAttribute method can cause a PBDOM_ATTRIBUTE (representing an existing attribute of the PBDOM_ELEMENT) to become detached from its owner PBDOM_ELEMENT.

For example, consider the following element:

<an_element an_attr="some_value"/>

If a PBDOM_ELEMENT object pbdom_an_elem represents the element an_element and the following statement is issued, the method first attempts to create a new attribute for the an_element element:

pbdom_an_elem.SetAttribute("an_attr", "some_other_value")

Then, because an_element already contains an attribute with the name an_attr, the attribute is removed. If there is an existing PBDOM_ATTRIBUTE object that represents the original an_attr attribute, this PBDOM_ATTRIBUTE is detached from its owner element (an_element).