ognl

Interface Node

All Superinterfaces:

JavaSource

All Known Implementing Classes:

ASTAdd, ASTAnd, ASTAssign, ASTBitAnd, ASTBitNegate, ASTBitOr, ASTChain, ASTConst, ASTCtor, ASTDivide, ASTEq, ASTEval, ASTGreater, ASTGreaterEq, ASTIn, ASTInstanceof, ASTKeyValue, ASTLessEq, ASTList, ASTMap, ASTMethod, ASTMultiply, ASTNegate, ASTNot, ASTNotEq, ASTNotIn, ASTOr, ASTProject, ASTProperty, ASTRemainder, ASTRootVarRef, ASTSelect, ASTSelectFirst, ASTSelectLast, ASTSequence, ASTShiftLeft, ASTShiftRight, ASTStaticField, ASTStaticMethod, ASTSubtract, ASTTest, ASTThisVarRef, ASTUnsignedShiftRight, ASTVarRef, ASTXor, BooleanExpression, ComparisonExpression, ExpressionNode, NumericExpression, SimpleNode

public interface Node
extends JavaSource

JJTree interface for AST nodes, as modified to handle the OGNL operations getValue and setValue. JJTree's original comment: All AST nodes must implement this interface. It provides basic machinery for constructing the parent and child relationships between nodes.

Author:

Luke Blanshard (blanshlu@netscape.net), Drew Davidson (drew@ognl.org)

Method Summary

Methods

Modifier and Type	Method and Description
ExpressionAccessor	getAccessor() Gets the compiled bytecode enhanced expression accessor for getting/setting values.
Object	getValue(OgnlContext context, Object source) Extracts the value from the given source object that is appropriate for this node within the given context.
void	jjtAddChild(Node n, int i) This method tells the node to add its argument to the node's list of children.
void	jjtClose() This method is called after all the child nodes have been added.
Node	jjtGetChild(int i) This method returns a child node.
int	jjtGetNumChildren() Return the number of children the node has.
Node	jjtGetParent()
void	jjtOpen() This method is called after the node has been made the current node.
void	jjtSetParent(Node n) This pair of methods are used to inform the node of its parent.
void	setAccessor(ExpressionAccessor accessor) Sets a new compiled accessor for this node expression.
void	setValue(OgnlContext context, Object target, Object value) Sets the given value in the given target as appropriate for this node within the given context.

Methods inherited from interface ognl.JavaSource

toGetSourceString, toSetSourceString

Method Detail

jjtOpen

void jjtOpen()

This method is called after the node has been made the current node. It indicates that child nodes can now be added to it.

jjtClose

void jjtClose()

This method is called after all the child nodes have been added.

jjtSetParent

void jjtSetParent(Node n)

This pair of methods are used to inform the node of its parent.

Parameters:

n - the Node to make the parent of this node.

jjtGetParent

Node jjtGetParent()

jjtAddChild

void jjtAddChild(Node n,
               int i)

This method tells the node to add its argument to the node's list of children.

Parameters:

n - the Node to add as a child of this node.

i - the position at which to add the child node.

jjtGetChild

Node jjtGetChild(int i)

This method returns a child node. The children are numbered from zero, left to right.

Parameters:

i - the position from which to get the child node.

Returns:

the child Node at position i.

jjtGetNumChildren

int jjtGetNumChildren()

Return the number of children the node has.

Returns:

the number of children for this node.

getValue

Object getValue(OgnlContext context,
              Object source)
                throws OgnlException

Extracts the value from the given source object that is appropriate for this node within the given context.

Parameters:

context - the OgnlContext within which to perform the operation.

source - the Object from which to get the value.

Returns:

the value from the source (as appropriate within the provided context).

Throws:

OgnlException - if the value get fails.

setValue

void setValue(OgnlContext context,
            Object target,
            Object value)
              throws OgnlException

Sets the given value in the given target as appropriate for this node within the given context.

Parameters:

context - the OgnlContext within which to perform the operation.

target - the Object upon which to set the value.

value - the Object representing the value to apply to the target.

Throws:

OgnlException - if the value set fails.

getAccessor

ExpressionAccessor getAccessor()

Gets the compiled bytecode enhanced expression accessor for getting/setting values.

Returns:

The accessor for this node, or null if none has been compiled for it.

setAccessor

void setAccessor(ExpressionAccessor accessor)

Sets a new compiled accessor for this node expression.

Parameters:

accessor - The compiled representation of this node.