public abstract class Parameter
extends java.lang.Object
Parameter
and thereby change the selection of dimension or measure elements that the query represents.
The createSource
method of a Parameter
creates a parameterized Source
. You then use the parameterized Source
as a parameter to a method that selects one or more elements of another Source
and produces a derived Source
. You can create a Cursor
for the Source
to retrieve the results of the query.
You can change the selection of elements that the derived Source
represents with the setValue
method of a concrete subclass of Parameter
. The Cursor
for the query Source
then has the values of the new selection. You do not need to create a new Cursor
. You can instead just get the values for the new selection from the existing Cursor
.
Modifier and Type | Method and Description |
---|---|
abstract java.lang.Object |
acceptVisitor(ParameterVisitor visitor, java.lang.Object context)
Calls the appropriate method of the specified
ParameterVisitor and passes that method the Parameter and the specified context Object . |
Source |
createSource()
Creates a
Source of the appropriate data type that contains the value specified for the Parameter . |
DataProvider |
getDataProvider()
Gets the
DataProvider for this Parameter . |
java.lang.String |
getID()
Gets a
String that uniquely identifies this Parameter during this connection. |
abstract java.lang.Object |
getValueObject()
Gets an
Object that contains the value for this Parameter . |
public abstract java.lang.Object acceptVisitor(ParameterVisitor visitor, java.lang.Object context)
ParameterVisitor
and passes that method the Parameter
and the specified context Object
.visitor
- An instance a class derived from the ParameterVisitor
class.context
- An Object
.Object
returned by the appropriate method of the specified ParameterVisitor
.public final DataProvider getDataProvider()
DataProvider
for this Parameter
.DataProvider
for this Parameter
.public final java.lang.String getID()
String
that uniquely identifies this Parameter
during this connection.String
that uniquely identifies this Parameter
.public abstract java.lang.Object getValueObject()
Object
that contains the value for this Parameter
.Object
that contains the value for this Parameter
.public Source createSource()
Source
of the appropriate data type that contains the value specified for the Parameter
. The concrete subclasses of Parameter
have constructors that take an initial value. An application can specify a different value by calling the setValue
of the subclass.Source
associated with the Parameter
.