Package org.zkoss.xel

Interface ExpressionFactory

All Known Implementing Classes:

ApacheELFactory, ApacheELFactory, BindXelFactory, BindXelFactoryEx, ELFactory, ELFactory, MVELFactory, OGNLFactory

public interface ExpressionFactory

Used to prepare expressions (Expression).

Since:

3.0.0

Author:

tomyeh

Field Summary

Fields

Modifier and Type	Field	Description
static int	FEATURE_CLASS	Used with isSupported(int) to know whether the factory supports FunctionMapperExt.resolveClass(java.lang.String)
static int	FEATURE_FUNCTION	Used with isSupported(int) to know whether the factory supports FunctionMapper.resolveFunction(java.lang.String, java.lang.String)

Method Summary

Modifier and Type	Method	Description
java.lang.Object	evaluate(XelContext ctx, java.lang.String expression, java.lang.Class<?> expectedType)	Evaluates an expression.
boolean	isSupported(int feature)	Returns whether an feature is supported.
Expression	parseExpression(XelContext ctx, java.lang.String expression, java.lang.Class<?> expectedType)	Prepares (a.k.a., compiles) an expression.

Field Detail

FEATURE_FUNCTION

static final int FEATURE_FUNCTION

Used with isSupported(int) to know whether the factory supports FunctionMapper.resolveFunction(java.lang.String, java.lang.String)

See Also:

Constant Field Values

FEATURE_CLASS

static final int FEATURE_CLASS

Used with isSupported(int) to know whether the factory supports FunctionMapperExt.resolveClass(java.lang.String)

See Also:

Constant Field Values

Method Detail

isSupported

boolean isSupported(int feature)

Returns whether an feature is supported.

Parameters:

feature - which feature to query. It can be a combination of FEATURE_FUNCTION and FEATURE_CLASS.

parseExpression

Expression parseExpression(XelContext ctx,
                           java.lang.String expression,
                           java.lang.Class<?> expectedType)
                    throws XelException

Prepares (a.k.a., compiles) an expression.

Parameters:

ctx - the context information to prepare the expression. It can be null, in which case no functions are supported for this invocation.

expression - the expression to be evaluated.

expectedType - the expected type of the result of the evaluation

Throws:

XelException

evaluate

java.lang.Object evaluate(XelContext ctx,
                          java.lang.String expression,
                          java.lang.Class<?> expectedType)
                   throws XelException

Evaluates an expression.

Parameters:

ctx - the context information to evaluate an expression. It can be null, in which case no functions are supported for this invocation.

expression - the expression to be evaluated. Note: the expression is enclosed with ${ and }, regardless of what implementation is used.

expectedType - the expected type of the result of the evaluation

Throws:

XelException