javax.servlet.jsp.tagext

Class TagExtraInfo

java.lang.Object

javax.servlet.jsp.tagext.TagExtraInfo

public abstract class TagExtraInfo
extends java.lang.Object

Extra tag information for a custom tag. It performs a similar function to BeanInfo classes, but for tag libraries. The TagExtraInfo class will be called at JSP compile time to:

1. instantiate and initialize runtime variables
2. validate tags

The TagExtraInfo class is specified in the TLD using the teiclass attribute:

 <tag>
   <name>foo</name>
   <tagclass>com.caucho.tags.FooTag</tagclass>
   <teiclass>com.caucho.tags.FooTagInfo</teiclass>
 </tag>
 

Constructor Summary

Constructors

Constructor and Description
TagExtraInfo() Implementing classes must implement a zero-arg constructor.

Method Summary

Modifier and Type	Method and Description
TagInfo	getTagInfo() Gets the TLD tag info for this tag.
VariableInfo[]	getVariableInfo(TagData data) Returns information needed to instantiate runtime variables.
boolean	isValid(TagData data) Validates the tag, so errors can be caught at compile-time instead of waiting for runtime.
void	setTagInfo(TagInfo tagInfo) Sets the TLD tag info for this tag.
ValidationMessage[]	validate(TagData data) Validates the tag.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Detail

TagExtraInfo

public TagExtraInfo()

Implementing classes must implement a zero-arg constructor.

Method Detail

getVariableInfo

public VariableInfo[] getVariableInfo(TagData data)

Returns information needed to instantiate runtime variables.

The default implementation returns null.

For example, if the tag initializes a nested integer named by the foo attribute, getVariableInfo might return the following:

 public VariableInfo []getVariableInfo(TagData data)
 {
   VariableInfo []info = new VariableInfo[1];
   String foo = data.getAttribute("foo");
   info[0] = new VariableInfo(foo, "int", true, VariableInfo.NESTED);
   return info;
 }
 

Parameters:

data - The tag's static attributes and values.

isValid

public boolean isValid(TagData data)

Validates the tag, so errors can be caught at compile-time instead of waiting for runtime.

The default implementation returns true.

setTagInfo

public final void setTagInfo(TagInfo tagInfo)

Sets the TLD tag info for this tag.

getTagInfo

public final TagInfo getTagInfo()

Gets the TLD tag info for this tag.

validate

public ValidationMessage[] validate(TagData data)

Validates the tag.