# apiBaseClassifier

The <apiBaseClassifier> element specifies a base classifier from which the classifier inherits part of its instance, structure, or behavior.

#### Description

Base classes are a useful way to group objects that share a common set of functionality. Base classes can provide a default set of functionality and allow customization though extension.

This element can provide an href attribute if the description of the API item is available. If the description is not available, the <apiBaseClassifier> element can provide the name of the API item in its contents.

- If you use an href attribute to a DITA API topic that describes the related API item, you do not need to provide any other information.

- If you provide an href attribute to some other format (such as HTML), you need to provide the name of the related API item inside the <apiBaseClassifier> element.

- If you cannot provide an href attribute (for instance, if the description of the related API item might not be available), you must provide the name of the related API item inside the <apiBaseClassifier> element and the fully qualified name of the element in the keyref attribute. The keyref attribute must provide a unique key such as a fully qualified classifier name for the named API item.

For example, in Java API specialization, the <apiBaseClassifier> represents the <javaBaseClass> for a superclass and the <javaBaseInterface> for a super interface.

#### Example

The following example shows a simple <apiBaseClassifier> element for a Visual Basic API class:

    <apiClassifier id="com.ibm.xtools.xde" outputclass="class" platform="vb">
        <apiName>RXEAbstraction</apiName>
        <shortdesc>Specifies one or more interfaces or interface members that will be implemented
            in the class or structure definition in which it appears.</shortdesc>
        <apiClassifierDetail>
           <apiClassifierDef>
    		<!– SYNTAX
              Public Class RXEAbstraction
              Inherits IRXEClass
            –>
              <apiQualifier name="access" value="public"/>
              <apiBaseClassifier>
                <apiItemName href=”IRXEClass”>IRXEClass</apiItemName>
                <apiDefNote>Required. A class whose properties, methods, and events will be
                    implemented by corresponding members in a class or structure.</apiDefNote>
              </apiBaseClassifier>
              <apiClassifierMember><apiItemName>RXEAbstraction</apiItemName>
              </apiClassifierMember>
           </apiClassifierDef>
    	</apiClassifierDetail>
    </apiClassifier>

#### Contained by

apiClassifierDef

#### Content model

(text data) (any number)

#### Inheritance

topic/xref reference/xref apiRef/apiRelation

Parent topic: apiClassifierDef