dods.dap.Server
Class ClauseFactory

java.lang.Object
  dods.dap.Server.ClauseFactory

public class ClauseFactory
extends Object

Represents a source of Clause objects for the constraint expression parser. By inheriting from this class and overriding the "newX" methods, you can create a factory that provides your own Clause objects instead of the default ones. This custom factory can be given to the parser via the CEEvaluator interface.

See Also:

CEEvaluator

Field Summary

protected FunctionLibrary

functionLibrary

Constructor Summary

ClauseFactory()
Creates a new clause factory with a blank function library.

ClauseFactory(FunctionLibrary functionLibrary)
Creates a clause factory which uses the specified function library.

Method Summary

TopLevelClause	newBoolFunctionClause(String functionName, List children) Generates a clause which invokes a function that returns a boolean value.
SubClause	newBTFunctionClause(String functionName, List children) Generates a clause which invokes a function that returns a BaseType.
SubClause	newDereferenceClause(String url) Generates a clause representing a remote value, referenced by a URL.
TopLevelClause	newRelOpClause(int operator, SubClause lhs, List rhs) Generates a clause which which compares subclauses, using one of the relative operators supported by the Operator class.
SubClause	newValueClause(dods.dap.BaseType value, boolean constant) Generates a clause representing a simple value, such as "var1" or "19".

Methods inherited from class java.lang.Object

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

Field Detail

functionLibrary

protected FunctionLibrary functionLibrary

Constructor Detail

ClauseFactory

public ClauseFactory()

Creates a new clause factory with a blank function library. This constructor is sufficient for servers with no server side functions.

See Also:

FunctionLibrary

ClauseFactory

public ClauseFactory(FunctionLibrary functionLibrary)

Creates a clause factory which uses the specified function library. This constructor allows you to parse CE's using a customized function library.

Parameters:

functionLibrary - The function library that will be used when creating clauses that invoke server-side functions.

Method Detail

newRelOpClause

public TopLevelClause newRelOpClause(int operator,
                                     SubClause lhs,
                                     List rhs)
                              throws SDODSException

Generates a clause which which compares subclauses, using one of the relative operators supported by the Operator class.

Throws:

SDODSException

newBoolFunctionClause

public TopLevelClause newBoolFunctionClause(String functionName,
                                            List children)
                                     throws SDODSException,
                                            dods.dap.NoSuchFunctionException

Generates a clause which invokes a function that returns a boolean value.

Throws:

SDODSException

dods.dap.NoSuchFunctionException

See Also:

BoolFunctionClause

newValueClause

public SubClause newValueClause(dods.dap.BaseType value,
                                boolean constant)
                         throws SDODSException

Generates a clause representing a simple value, such as "var1" or "19".

Throws:

SDODSException

See Also:

ValueClause

newBTFunctionClause

public SubClause newBTFunctionClause(String functionName,
                                     List children)
                              throws SDODSException,
                                     dods.dap.NoSuchFunctionException

Generates a clause which invokes a function that returns a BaseType.

Throws:

SDODSException

dods.dap.NoSuchFunctionException

See Also:

BTFunctionClause

newDereferenceClause

public SubClause newDereferenceClause(String url)
                               throws SDODSException

Generates a clause representing a remote value, referenced by a URL. Note that dereferencing is not currently supported, and the default implementation of this clause type throws an exception when it is evaluated.

Throws:

SDODSException

See Also:

DereferenceClause