Package org.apache.taglibs.standard.lang.jstl

Class Evaluator

java.lang.Object

org.apache.taglibs.standard.lang.jstl.Evaluator

All Implemented Interfaces:

ExpressionEvaluator

public class Evaluator
extends Object
implements ExpressionEvaluator

This is the expression evaluator "adapter" that customizes it for use with the JSP Standard Tag Library. It uses a VariableResolver implementation that looks up variables from the PageContext and also implements its implicit objects. It also wraps ELExceptions in JspExceptions that describe the attribute name and value causing the error.

Version:

$Change: 181177 $$DateTime: 2001/06/26 08:45:09 $$Author: kchung $

Author:

Nathan Abramson - Art Technology Group, Shawn Bayern

Constructor Summary

Constructors

Constructor	Description
Evaluator()

Method Summary

Modifier and Type	Method	Description
Object	evaluate(String pAttributeName, String pAttributeValue, Class pExpectedType, javax.servlet.jsp.tagext.Tag pTag, javax.servlet.jsp.PageContext pPageContext)	Conduit to old-style call for convenience.
Object	evaluate(String pAttributeName, String pAttributeValue, Class pExpectedType, javax.servlet.jsp.tagext.Tag pTag, javax.servlet.jsp.PageContext pPageContext, Map functions, String defaultPrefix)	Evaluates the expression at request time
static String	parseAndRender(String pAttributeValue)	Parses the given attribute value, then converts it back to a String in its canonical form.
String	validate(String pAttributeName, String pAttributeValue)	Translation time validation of an attribute value.

Methods inherited from class java.lang.Object

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

Constructor Detail

Evaluator

public Evaluator()

Method Detail

validate

public String validate(String pAttributeName,
                       String pAttributeValue)

Translation time validation of an attribute value. This method will return a null String if the attribute value is valid; otherwise an error message.

Specified by:

validate in interface ExpressionEvaluator

evaluate

public Object evaluate(String pAttributeName,
                       String pAttributeValue,
                       Class pExpectedType,
                       javax.servlet.jsp.tagext.Tag pTag,
                       javax.servlet.jsp.PageContext pPageContext,
                       Map functions,
                       String defaultPrefix)
                throws javax.servlet.jsp.JspException

Evaluates the expression at request time

Throws:

javax.servlet.jsp.JspException

evaluate

public Object evaluate(String pAttributeName,
                       String pAttributeValue,
                       Class pExpectedType,
                       javax.servlet.jsp.tagext.Tag pTag,
                       javax.servlet.jsp.PageContext pPageContext)
                throws javax.servlet.jsp.JspException

Conduit to old-style call for convenience.

Specified by:

evaluate in interface ExpressionEvaluator

Throws:

javax.servlet.jsp.JspException

parseAndRender

public static String parseAndRender(String pAttributeValue)
                             throws javax.servlet.jsp.JspException

Parses the given attribute value, then converts it back to a String in its canonical form.

Throws:

javax.servlet.jsp.JspException