org.apache.tapestry.services
Interface ExpressionEvaluator

All Known Implementing Classes:

ExpressionEvaluatorImpl

public interface ExpressionEvaluator

Wrapper around the OGNL library.

Since:

4.0

Author:

Howard M. Lewis Ship

Method Summary

boolean	isConstant(java.lang.String expression) Returns true if the expression evaluates to a constant or other literal value.
java.lang.Object	read(java.lang.Object target, java.lang.String expression) Reads a property of the target, defined by the expression.
java.lang.Object	readCompiled(java.lang.Object target, java.lang.Object expression) Reads a property of the target, defined by the (previously compiled) expression.
void	write(java.lang.Object target, java.lang.String expression, java.lang.Object value) Updates a property of the target, defined by the expression.
void	writeCompiled(java.lang.Object target, java.lang.Object expression, java.lang.Object value) Updates a property of the target, defined by the (previously compiled) expression.

Method Detail

read

public java.lang.Object read(java.lang.Object target,
                             java.lang.String expression)

Reads a property of the target, defined by the expression.

Throws:

org.apache.hivemind.ApplicationRuntimeException - if the expression can not be parsed, or if some other error occurs during evaluation of the expression.

readCompiled

public java.lang.Object readCompiled(java.lang.Object target,
                                     java.lang.Object expression)

Reads a property of the target, defined by the (previously compiled) expression.

Throws:

org.apache.hivemind.ApplicationRuntimeException - if some other error occurs during evaluation of the expression.

write

public void write(java.lang.Object target,
                  java.lang.String expression,
                  java.lang.Object value)

Updates a property of the target, defined by the expression.

Throws:

org.apache.hivemind.ApplicationRuntimeException - if the expression can not be parsed, or if some other error occurs during evaluation of the expression.

writeCompiled

public void writeCompiled(java.lang.Object target,
                          java.lang.Object expression,
                          java.lang.Object value)

Updates a property of the target, defined by the (previously compiled) expression.

Throws:

org.apache.hivemind.ApplicationRuntimeException - if some other error occurs during evaluation of the expression.

isConstant

public boolean isConstant(java.lang.String expression)

Returns true if the expression evaluates to a constant or other literal value.

Throws:

org.apache.hivemind.ApplicationRuntimeException - if the expression is not valid