PBDOM_ATTRIBUTE

The PBDOM_ATTRIBUTE class represents an XML attribute modeled in PowerScript. The PBDOM_ATTRIBUTE methods allow access to element attributes and namespace information.

Methods

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

GetBooleanValue, SetBooleanValue, GetDateValue, SetDateValue, GetDateTimeValue, SetDateTimeValue, GetDoubleValue, SetDoubleValue, GetIntValue, SetIntValue, GetLongValue, SetLongValue, GetRealValue, SetRealValue, GetTimeValue, SetTimeValue, GetUIntValue, SetUintValue, GetULongValue,and SetULongValue to get and set the value of the PBDOM_ATTRIBUTE as the specified datatype
GetNamespacePrefix and GetNamespaceURI to get the prefix and URI of the namespace associated with the PBDOM_ATTRIBUTE
GetOwnerElementObject and SetOwnerElementObject to get and set the owner PBDOM_ELEMENT of the PBDOM_ATTRIBUTE
GetQualifiedName to get the full name of the PBDOM_ATTRIBUTE including the prefix, if any
SetNamespace to set the namespace of the PBDOM_ATTRIBUTE
SetText to set the text content of the PBDOM_ATTRIBUTE

Child PBDOM_OBJECTs

A PBDOM_ATTRIBUTE contains a subtree of child PBDOM_OBJECTs. The child objects can be a combination of PBDOM_TEXT and PBDOM_ENTITYREFERENCE objects.

The following example produces a PBDOM_ELEMENT named elem that contains a PBDOM_ATTRIBUTE named attr:

PBDOM_ATTRIBUTE pbdom_attr
PBDOM_TEXT pbdom_txt
PBDOM_ENTITYREFERENCE pbdom_er
PBDOM_ELEMENT pbdom_elem

pbdom_elem  = Create PBDOM_ELEMENT 
pbdom_elem.SetName ("elem")

pbdom_attr = Create PBDOM_ATTRIBUTE
pbdom_attr.SetName("attr")
pbdom_attr.SetText("Part 1 ")

pbdom_txt = Create PBDOM_TEXT
pbdom_txt.SetText (" End.")

pbdom_er = Create PBDOM_ENTITYREFERENCE 
pbdom_er.SetName("ER")

pbdom_attr.AddContent(pbdom_er)
pbdom_attr.AddContent(pbdom_txt)

pbdom_elem.SetAttribute(pbdom_attr)

The element tag in the XML looks like this:

<elem attr="Part 1 &ER; End.">

In Figure 14-3, the arrows indicate a parent-child relationship between the PBDOM_ATTRIBUTE and the other PBDOM_OBJECTs:

Figure 14-3: PBDOM_ATTRIBUTE subtree example

Arrows indicate a parent-child relationship between the P B DOM _ ATTRIBUTE a t t r and the P B DOM _ OBJECTs P B DOM _ TEXT Part 1, P B DOM _ ENTITY REFERENCE E R, and P B DOM _ TEXT End.

The Default PBDOM_TEXT child

A PBDOM_ATTRIBUTE generally always contains at least one PBDOM_TEXT child that might contain an empty string. This is the case unless the RemoveContent method has been called to remove all contents of the PBDOM_ATTRIBUTE.

The following examples show how a PBDOM_TEXT object with an empty string can become the child of a PBDOM_ATTRIBUTE.

Example 1 The following example uses the PBDOM_ELEMENT SetAttribute method. The name of the PBDOM_ATTRIBUTE is set to attr but the text value is an empty string. The PBDOM_ATTRIBUTE will have one child PBDOM_TEXT that will contain an empty string:

PBDOM_DOCUMENT  pbdom_doc
PBDOM_ATTRIBUTE  pbdom_attr
PBDOM_OBJECT    pbdom_obj_array[]

try

  pbdom_doc = Create PBDOM_DOCUMENT
  pbdom_doc.NewDocument("root")

  // Note that the name of the attribute is set to
  // "attr" and its text value is the empty string ""
  pbdom_doc.GetRootElement().SetAttribute("attr", "")
  
  pbdom_attr = &
     pbdom_doc.GetRootElement().GetAttribute("attr")

  MessageBox ("HasChildren", &
     string(pbdom_attr.HasChildren()))
  
catch(PBDOM_EXCEPTION pbdom_except)
  MessageBox ("PBDOM_EXCEPTION", &
     pbdom_except.GetMessage())
end try

When you use the SaveDocument method to render pbdom_doc as XML, it looks like this:

<root attr="" />

Example 2 The following example creates a PBDOM_ATTRIBUTE and sets its name to attr. No text value is set, but a PBDOM_TEXT object is automatically created and attached to the PBDOM_ATTRIBUTE. This is the default behavior for every PBDOM_ATTRIBUTE created in this way:

PBDOM_DOCUMENT  pbdom_doc
PBDOM_ATTRIBUTE  pbdom_attr

try
  pbdom_doc = Create PBDOM_DOCUMENT
  pbdom_doc.NewDocument("root")
  
  // Create a PBDOM_ATTRIBUTE and set its name to "attr"
  pbdom_attr = Create PBDOM_ATTRIBUTE
  pbdom_attr.SetName("attr")

  pbdom_doc.GetRootElement().SetAttribute(pbdom_attr)
  
  MessageBox ("HasChildren", &
     string(pbdom_attr.HasChildren()))
  
catch(PBDOM_EXCEPTION pbdom_except)
  MessageBox ("PBDOM_EXCEPTION", &
     pbdom_except.GetMessage())
end try

When you call the SetText method (or any of the other Set* methods except SetNamespace), the default PBDOM_TEXT is replaced by a new PBDOM_TEXT. If you call the SetContent method, you can replace the default PBDOM_TEXT by a combination of PBDOM_TEXT and PBDOM_ENTITYREFERENCE objects.