opendap.servers

Class ClauseFactory

java.lang.Object

opendap.servers.ClauseFactory

public class ClauseFactory
extends java.lang.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

Fields

Modifier and Type	Field and Description
protected FunctionLibrary	functionLibrary

Constructor Summary

Constructors

Constructor and Description
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

Modifier and Type	Method and Description
TopLevelClause	newBoolFunctionClause(java.lang.String functionName, java.util.List children) Generates a clause which invokes a function that returns a boolean value.
SubClause	newBTFunctionClause(java.lang.String functionName, java.util.List children) Generates a clause which invokes a function that returns a BaseType.
SubClause	newDereferenceClause(java.lang.String url) Generates a clause representing a remote value, referenced by a URL.
TopLevelClause	newRelOpClause(int operator, SubClause lhs, java.util.List rhs) Generates a clause which which compares subclauses, using one of the relative operators supported by the Operator class.
SubClause	newValueClause(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,
                                     java.util.List rhs)
                              throws DAP2ServerSideException

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

Throws:

DAP2ServerSideException

newBoolFunctionClause

public TopLevelClause newBoolFunctionClause(java.lang.String functionName,
                                            java.util.List children)
                                     throws DAP2ServerSideException,
                                            NoSuchFunctionException

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

Throws:

DAP2ServerSideException

NoSuchFunctionException

See Also:

BoolFunctionClause

newValueClause

public SubClause newValueClause(BaseType value,
                                boolean constant)
                         throws DAP2ServerSideException

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

Throws:

DAP2ServerSideException

See Also:

ValueClause

newBTFunctionClause

public SubClause newBTFunctionClause(java.lang.String functionName,
                                     java.util.List children)
                              throws DAP2ServerSideException,
                                     NoSuchFunctionException

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

Throws:

DAP2ServerSideException

NoSuchFunctionException

See Also:

BTFunctionClause

newDereferenceClause

public SubClause newDereferenceClause(java.lang.String url)
                               throws DAP2ServerSideException

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:

DAP2ServerSideException

See Also:

DereferenceClause