oracle.olapi.data.source
Class DynamicDefinition

java.lang.Object
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  +--oracle.olapi.data.source.SourceDefinition
        |
        +--oracle.olapi.data.source.DynamicDefinition

public final class DynamicDefinition

extends SourceDefinition

A proxy for the SourceDefinition of the Source returned by the SourceGenerator for a Template. An application creates a DynamicDefinition for a Template by calling the createDynamicDefinition method on the Template and passing it a SourceGenerator. The application can then generate the Source defined by the Template by calling the getSource method of the DynamicDefinition. The DynamicDefinition inherits the getSource method from SourceDefinition.

When an application calls the getSource method of the DynamicDefinition, the generateSource method of the SourceGenerator is called. That method uses the values stored in the MetadataState for the Template to create the Source returned by getSource. If the Source has no inputs, the application can create a Cursor for the Source to retrieve the data it specifies from the data store.

An application can modify the query produced by the Template by calling methods of the Template to change the values of one or more of the fields in its MetadataState object. The application can then call the getSource method of the DynamicDefinition again to generate a Source using the new values or different logic or both. The instances of the Template and DynamicDefinition objects remain the same but the Source that the Template produces has changed.

See Also:

MetadataState, SourceGenerator, Template

getCurrent

public final SourceDefinition getCurrent()

Gets the SourceDefinition for the Source currently returned by the generateSource method of the SourceGenerator for this DynamicDefinition. The relationship between that SourceDefinition and the Source is immutable. For example, if the current state of the Template components is such that the generateSource method returns the result of a join method call, then a call to getCurrent returns a JoinDefinition. Calling the getSource method of that JoinDefinition always returns the same Source, the Source that is paired to it.

In contrast, the getSource method of DynamicDefinition returns the Source that the generateSource method produces. The DynamicDefinition is a proxy for the SourceDefinition that is immutably paired to the Source. Thus if the current state of the values used to create the Source changes, then the getSource method returns a different Source, yet the DynamicDefinition remains the same.

The getCurrent method is primarily informational, and is not used by an application in building a query. An application uses the getSource method to get the Source for the Template and then uses that Source in building a complex query or in the process of creating a Cursor for retrieving the data defined by the Source.

Returns:

The SourceDefinition for the Source currently generated by the SourceGenerator.

getSourceGenerator

public final SourceGenerator getSourceGenerator()

Gets the SourceGenerator for this DynamicDefinition.

Returns:

The SourceGenerator for this DynamicDefinition.

getTemplate

public final Template getTemplate()

Gets the Template whose createDynamicDefinition method returned this DynamicDefinition.

Returns:

The Template used in creating this DynamicDefinition.

isModified

public final boolean isModified(Transaction transaction)

Indicates whether, in the specified Transaction, the Template for this DynamicDefinition has changed the Source that it generates for this DynamicDefinition.

Parameters:

transaction - The Transaction to specify.

Returns:

true if the Source has been modified in the specified Transaction and false if it has not.