com.im.df.api.dml
Class DFTerm

java.lang.Object
  com.im.df.api.dml.DFTerm

Direct Known Subclasses:

DFTermExpression, DFTermField, DFTermValue

public abstract class DFTerm
extends Object

This object is a superclass of all objects used for definition of expression terms for query execution in DIF.

Method Summary

abstract void	accept(DFTermVisitor visitor)
abstract Class<? extends DFFieldDataTypeCapability>	getTermReturnType() Compute the return type of the term.
TermErrors	validate(DFDataTree dataTree) Validate the term.

Methods inherited from class java.lang.Object

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

Method Detail

validate

public final TermErrors validate(DFDataTree dataTree)

Validate the term.

Parameters:

dataTree - The parameter is optional (it means it can be null). If dataTree is specified the term is validated in context of the datatree otherwise (if null) it is supposed that the whole term is defined inside one DFEntity

Returns:

The result of validation. Never returns null.

getTermReturnType

public abstract Class<? extends DFFieldDataTypeCapability> getTermReturnType()

Compute the return type of the term. Can return null if it cannot be determined.

Returns:

The class which is subclass of DFFieldDataTypeCapability or null

accept

public abstract void accept(DFTermVisitor visitor)