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ExtractorEventTransformer Class

Oracle® Fusion Middleware .NET API Reference for Oracle Coherence
14c (14.1.1.0)
F23534-02
ExtractorEventTransformer is a special purpose ICacheEventTransformer implementation that transforms emitted events, extracting one or more properties from either the "OldValue" or the "NewValue".
Inheritance Hierarchy
SystemObject
  Tangosol.Util.TransformerExtractorEventTransformer

Namespace:  Tangosol.Util.Transformer
Assembly:  Coherence (in Coherence.dll) Version: 14.1.1.14 (14.1.1.14)
Syntax
C#
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public class ExtractorEventTransformer : ICacheEventTransformer, 
	IPortableObject

The ExtractorEventTransformer type exposes the following members.

Constructors
  NameDescription
Public methodExtractorEventTransformer
Default constructor.
Public methodExtractorEventTransformer(String)
Construct a ExtractorEventTransformer that transforms CacheEventArgs's values based on the specified method name.
Public methodExtractorEventTransformer(IValueExtractor)
Construct a ExtractorEventTransformer that transforms CacheEventArgs values based on the specified extractor.
Public methodExtractorEventTransformer(IValueExtractor, IValueExtractor)
Construct a ExtractorEventTransformer that transforms CacheEventArgs values based on the specified extractors.
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Properties
  NameDescription
Public propertyNewValueExtractor
Return a IValueExtractor used to transfrom the event's NewValue.
Public propertyOldValueExtractor
Return a IValueExtractor used to transfrom the event's OldValue.
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Methods
  NameDescription
Public methodEquals(Object)
Compare the ExtractorEventTransformer with another object to determine equality.
(Overrides ObjectEquals(Object).)
Public methodEquals(ExtractorEventTransformer)
Compare the ExtractorEventTransformer with another object to determine equality.
Protected methodFinalize
Allows an object to try to free resources and perform other cleanup operations before it is reclaimed by garbage collection.
(Inherited from Object.)
Public methodGetHashCode
Determine a hash value for the ExtractorEventTransformer object according to the general Object.GetHashCode contract.
(Overrides ObjectGetHashCode.)
Public methodGetType
Gets the Type of the current instance.
(Inherited from Object.)
Protected methodMemberwiseClone
Creates a shallow copy of the current Object.
(Inherited from Object.)
Public methodReadExternal
Restore the contents of a user type instance by reading its state using the specified IPofReader object.
Public methodToString
Provide a human-readable representation of this object.
(Overrides ObjectToString.)
Public methodTransform
Transform the specified CacheEventArgs using the corresponding extractors.
Public methodWriteExternal
Save the contents of a POF user type instance by writing its state using the specified IPofWriter object.
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Remarks
This transformation will generally result in the change of the values' data type.

Example: the following code will register a listener to receive events only if the value of the "AccountBalance" property changes. The transformed event's "NewValue" will be a IList containing the "LastTransactionTime" and "AccountBalance" properties. The "OldValue" will always be null.

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IFilter filter = new ValueChangeEventFilter("AccountBalance");
IValueExtractor extractor = new MultiExtractor("LastTransactionTime,AccountBalance");
ICacheEventTransformer transformer = new ExtractorEventTransformer(null, extractor);

cache.AddCacheListener(listener,
                       new CacheEventTransformerFilter(filter,
                                                       transformer),
                       false);

See Also