com.massa.mrules.accessor

Class MCoalesceAccessor

java.lang.Object

com.massa.mrules.base.AbstractMRulesObject

com.massa.mrules.addon.AbstractAddon

com.massa.mrules.accessor.AbstractReadAccessor

com.massa.mrules.accessor.MCoalesceAccessor

All Implemented Interfaces:

IAccessor, IReadAccessor, IAddon, IMRulesObject, Outable, Serializable, Cloneable

@PersistantProperties(properties=@PersistantProperty(property="sources",alias="source"))
public class MCoalesceAccessor
extends AbstractReadAccessor

Returns the first non-null result of the sub-accessors.

See Also:

Serialized Form

Nested Class Summary

Nested classes/interfaces inherited from interface com.massa.mrules.accessor.IReadAccessor

IReadAccessor.Standalone

Field Summary

Fields

Modifier and Type	Field and Description
static String	COALESCE_ID

Constructor Summary

Constructors

Constructor and Description
MCoalesceAccessor()
MCoalesceAccessor(IReadAccessor... sources)
MCoalesceAccessor(List<IReadAccessor> sources)

Method Summary

Modifier and Type	Method and Description
MCoalesceAccessor	clone() Clones the Addon.
<G,C extends Collection<G>> void	compileCollection(ICompilationContext ctxt, Class<C> expectedType, Class<G> expectedGenericType) Implementation to handle case when expected result is a Collection.
void	compileValue(ICompilationContext ctxt, Class<?> expectedType) Implementation to handle case when expected result is a single value.
boolean	equals(Object o)
CostInfo	getEstimatedReadCost(ICompilationContext ctxt) Estimates the reading complexity, to allow callers to optimize calls.
Class<?>	getGenericCollectionType(IContext ctxt) Returns the Generic type, if value is a collection or an array, evaluated : at compilation time for standard compilation at runtime for light compilation and execution phase or null if the type can't be resolved or value is not a collection.
Class<?>[]	getGenericTypes(IContext ctxt) By default, creates a 1 cell array with IAccessor.getGenericCollectionType(IContext) return value if any, or null if no value.
String	getImplementationId() Unique addon implementation ID.
List<IReadAccessor>	getSources()
Class<?>	getType(IContext ctxt) Returns the value's class, evaluated : at compilation time for standard compilation at runtime for light compilation or null if the type can't be resolved.
int	hashCode()
protected Object	internalGet(IExecutionContext ctxt) Specific addon implementation must be here.
boolean	isCacheUsed() Returns false by default.
boolean	isShouldIterate() If this iterator is dedicated to iterate over values, then it should be precised.
void	setSources(List<IReadAccessor> sources)
void	toString(OuterWithLevel outer) Method used to send String representation of the current object to the OuterWithLevel.

Methods inherited from class com.massa.mrules.accessor.AbstractReadAccessor

castToExpected, compileRead, compileRead, compileRead, compileRead, get, isConstantValue, isShouldBeWrappedToConstantValue, isShouldNotCache

Methods inherited from class com.massa.mrules.addon.AbstractAddon

getInternalCacheIdentifier, isInternalCacheIdentifierNeeded, optimize, resetCachedData, setInternalCacheIdentifier, toString, wasRegistered

Methods inherited from class com.massa.mrules.base.AbstractMRulesObject

getDebugInfo, getDescription, getName, setDebugInfo, setDescription, setName

Methods inherited from class java.lang.Object

finalize, getClass, notify, notifyAll, wait, wait, wait

Methods inherited from interface com.massa.mrules.addon.IAddon

getInternalCacheIdentifier, isInternalCacheIdentifierNeeded, optimize, resetCachedData, setInternalCacheIdentifier, wasRegistered

Methods inherited from interface com.massa.mrules.base.IMRulesObject

getDebugInfo, getDescription, getName, setDebugInfo, setDescription, setName

Field Detail

COALESCE_ID

public static final String COALESCE_ID

See Also:

Constant Field Values

Constructor Detail

MCoalesceAccessor

public MCoalesceAccessor()

MCoalesceAccessor

public MCoalesceAccessor(List<IReadAccessor> sources)

MCoalesceAccessor

public MCoalesceAccessor(IReadAccessor... sources)

Method Detail

compileValue

public void compileValue(ICompilationContext ctxt,
                         Class<?> expectedType)
                  throws MRuleValidationException

Description copied from class: AbstractReadAccessor

Implementation to handle case when expected result is a single value.

Specified by:

compileValue in class AbstractReadAccessor

Throws:

MRuleValidationException

compileCollection

public <G,C extends Collection<G>> void compileCollection(ICompilationContext ctxt,
                                                          Class<C> expectedType,
                                                          Class<G> expectedGenericType)
                                                   throws MRuleValidationException

Description copied from class: AbstractReadAccessor

Implementation to handle case when expected result is a Collection.

Specified by:

compileCollection in class AbstractReadAccessor

Throws:

MRuleValidationException

getEstimatedReadCost

public CostInfo getEstimatedReadCost(ICompilationContext ctxt)
                              throws MRuleValidationException

Description copied from interface: IReadAccessor

Estimates the reading complexity, to allow callers to optimize calls. Calls to this method should be done on a compiled accessor, so that all information is available to compute complexity.
Calls to non-compiled instance may return non-accurate results.

Parameters:

ctxt - Compilation context.

Throws:

MRuleValidationException - if validation problem detected.

internalGet

protected Object internalGet(IExecutionContext ctxt)
                      throws MAccessorException

Description copied from class: AbstractReadAccessor

Specific addon implementation must be here.

Specified by:

internalGet in class AbstractReadAccessor

Throws:

MAccessorException

getType

public Class<?> getType(IContext ctxt)
                 throws MAccessorException

Description copied from interface: IAccessor

Returns the value's class, evaluated :

• at compilation time for standard compilation
• at runtime for light compilation

or null if the type can't be resolved.

Throws:

MAccessorException

getGenericCollectionType

public Class<?> getGenericCollectionType(IContext ctxt)
                                  throws MAccessorException

Description copied from interface: IAccessor

Returns the Generic type, if value is a collection or an array, evaluated :

• at compilation time for standard compilation
• at runtime for light compilation and execution phase

or null if the type can't be resolved or value is not a collection.

Throws:

MAccessorException

getGenericTypes

public Class<?>[] getGenericTypes(IContext ctxt)
                           throws MAccessorException

Description copied from class: AbstractReadAccessor

By default, creates a 1 cell array with IAccessor.getGenericCollectionType(IContext) return value if any, or null if no value.

Specified by:

getGenericTypes in interface IAccessor

Overrides:

getGenericTypes in class AbstractReadAccessor

Throws:

MAccessorException

isShouldIterate

public boolean isShouldIterate()

Description copied from interface: IReadAccessor

If this iterator is dedicated to iterate over values, then it should be precised. In this case, the "get" method should return an Iterator, of instances of "getType".
Non-read only accessors should not be iterable. BUT it's not mandatory. In this particular case, the "set" method should be described precisely ...
Please not that returned Iterators should not support the "remove" method.
They also should use MRuleInternalRuntimeException if Exception must be thrown.
This method is not dependent on the compilation process. it can be called before and will return the correct result.

getImplementationId

public String getImplementationId()

Description copied from interface: IAddon

Unique addon implementation ID. In case of conflict, an Class Initialization error will be raised.

isCacheUsed

public boolean isCacheUsed()

Description copied from class: AbstractAddon

Returns false by default.

Specified by:

isCacheUsed in interface IAddon

Overrides:

isCacheUsed in class AbstractAddon

clone

public MCoalesceAccessor clone()

Description copied from interface: IAddon

Clones the Addon.
The general contract is that the clone of a compiled Addon is still compiled.

Specified by:

clone in interface IAccessor

Specified by:

clone in interface IReadAccessor

Specified by:

clone in interface IAddon

Specified by:

clone in interface IMRulesObject

Overrides:

clone in class AbstractReadAccessor

equals

public boolean equals(Object o)

Overrides:

equals in class Object

hashCode

public int hashCode()

Overrides:

hashCode in class Object

toString

public void toString(OuterWithLevel outer)
              throws IOException

Description copied from interface: Outable

Method used to send String representation of the current object to the OuterWithLevel.

Throws:

IOException

getSources

public List<IReadAccessor> getSources()

setSources

public void setSources(List<IReadAccessor> sources)