XML Reference: Siebel Enterprise Application Integration > XML Integration Objects and the DTD Wizard >

How the DTD Wizard Creates XML Integration Objects

XML integration objects consist of the following:

• Elements
• Attributes
• Element's #PCDATA
• Names
• Hierarchy
• Connectors
• Cardinality

CAUTION:  The DTD Wizard removes recursion by breaking loops. Repeating entities in XML at run time are not supported.

Elements

Generally, XML elements map to components within integration objects. However, in many cases the component is so simple that it is a performance optimization to map these elements into component fields of the parent element rather than as child components.

Elements are expressed this way (within brackets and starting with an exclamation point):

<!ELEMENT car (year, model, color+)>

An element can be mapped to a component field when the following three properties are satisfied:

• The component field must match an element within the DTD.
• The component field must match the cardinality of the element in the DTD; in other words, if the DTD specifies only one instance of this element type is valid, all subsequent appearances of this element type are illegal.
• The element must appear within the root element; any element appearing outside of the root is illegal.

When an element is mapped to component field, the component field has the property XML Style set to Element.

Attributes

Attributes include additional information related to an element, can be either required or implied (optional), and might have a default value. For example, an element might be a car with soundsystem, transmission, and doors as attributes. Soundsystem can be any text and is required; transmission is required because there is a default listed; other is optional.This would be expressed this way:

<!ELEMENT car>

<!ATTLLST car

        soundsystem      CDATA        #REQUIRED

        transmission     (automatic | manual | 5-speed-manual) "automatic"

        other            CDATA        #IMPLIED>

Attributes are always mapped to component fields and are related directly to elements. The component field within Siebel application has the XML Style property set to Attribute.

Element's #PCDATA

If the element is mapped to an integration component, then its #PCDATA is mapped to a component field <!Element> #PCDATA. If the element is mapped to a field, then the #PCDATA is mapped to the value of the field.

Names

Name is the name of the component or the field of the integration object. Because these names have to be unique within an integration object, the names might have suffixes attached to make them unique.

• Property External Name is the name of the attribute or the element in the external system, such as CustName.
• Property XML Tag is the name of the tag in the XML, such as <customer>.

Hierarchy

The parent components of integration components in an integration object correspond to their parents in XML. For integration component fields, if the property XML Parent Field is set, then the field in the same component with its Name value equal to the XML Parent Field corresponds to the parent in the XML. This happens because elements can be mapped to fields of integration components.

For integration component fields, if the property XML Parent Field is not set, then the parent component corresponds to the parent in the XML.

Connectors

Connectors specify the order of elements and either/or relationships, if one exists, as shown in Table 14.

CAUTION:  The Siebel DTD wizard does not support "one or the other" ( | ) relationships expressed in DTDs. "One or the other" ( | ) will be treated the same as "followed by" ( , ).

Cardinality

As shown in Table 15, the DTD syntax allows you to specify a cardinality (the number of times an element can appear within an XML document) for elements using the following modifiers: question mark (?), plus sign (+), and asterisk (*), or none. Elements with a cardinality, or occurrence, specified in a DTD map only to Integration Components. The Cardinality property in the Integration Component within Siebel maps to the specified cardinality information in the DTD.

The specification for DTDs supports using parentheses to express complex hierarchical structures. For example:

<!ELEMENT rating ((tutorial | reference)*, overall)+ >

The DTD Wizard uses the operator (?, *, +, or "none") closest to the child element as that child element's cardinality. In addition, the DTD Wizard will ignore such grouping by parentheses as illustrated in the preceding example.