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Home » apache-tomcat-6.0.26-src » javax » servlet » jsp » tagext » [javadoc | source]
javax.servlet.jsp.tagext
public class: TagSupport [javadoc | source]
java.lang.Object
   javax.servlet.jsp.tagext.TagSupport

All Implemented Interfaces:
    IterationTag, Serializable

Direct Known Subclasses:
    LoopTagSupport, ConditionalTagSupport, BodyTagSupport

A base class for defining new tag handlers implementing Tag.

The TagSupport class is a utility class intended to be used as the base class for new tag handlers. The TagSupport class implements the Tag and IterationTag interfaces and adds additional convenience methods including getter methods for the properties in Tag. TagSupport has one static method that is included to facilitate coordination among cooperating tags.

Many tag handlers will extend TagSupport and only redefine a few methods.
Field Summary
protected  String id    The value of the id attribute of this tag; or null. 
protected  PageContext pageContext    The PageContext. 
Constructor:
 public TagSupport() 
Method from javax.servlet.jsp.tagext.TagSupport Summary:
doAfterBody,   doEndTag,   doStartTag,   findAncestorWithClass,   getId,   getParent,   getValue,   getValues,   release,   removeValue,   setId,   setPageContext,   setParent,   setValue
Methods from java.lang.Object:
clone,   equals,   finalize,   getClass,   hashCode,   notify,   notifyAll,   toString,   wait,   wait,   wait
Method from javax.servlet.jsp.tagext.TagSupport Detail:
 public int doAfterBody() throws JspException 
    Default processing for a body.
 public int doEndTag() throws JspException 
    Default processing of the end tag returning EVAL_PAGE.
 public int doStartTag() throws JspException 
    Default processing of the start tag, returning SKIP_BODY.
 public static final Tag findAncestorWithClass(Tag from,
    Class klass) 
    Find the instance of a given class type that is closest to a given instance. This method uses the getParent method from the Tag interface. This method is used for coordination among cooperating tags.

    The current version of the specification only provides one formal way of indicating the observable type of a tag handler: its tag handler implementation class, described in the tag-class subelement of the tag element. This is extended in an informal manner by allowing the tag library author to indicate in the description subelement an observable type. The type should be a subtype of the tag handler implementation class or void. This addititional constraint can be exploited by a specialized container that knows about that specific tag library, as in the case of the JSP standard tag library.

    When a tag library author provides information on the observable type of a tag handler, client programmatic code should adhere to that constraint. Specifically, the Class passed to findAncestorWithClass should be a subtype of the observable type.

 public String getId() 
    The value of the id attribute of this tag; or null.
 public Tag getParent() 
    The Tag instance most closely enclosing this tag instance.
 public Object getValue(String k) 
    Get a the value associated with a key.
 public Enumeration<String> getValues() 
    Enumerate the keys for the values kept by this tag handler.
 public  void release() 
    Release state.
 public  void removeValue(String k) 
    Remove a value associated with a key.
 public  void setId(String id) 
    Set the id attribute for this tag.
 public  void setPageContext(PageContext pageContext) 
    Set the page context.
 public  void setParent(Tag t) 
    Set the nesting tag of this tag.
 public  void setValue(String k,
    Object o) 
    Associate a value with a String key.