com.massa.mrules.accessor

Interface IReadAccessor

All Superinterfaces:

Cloneable, IAccessor, IAddon, IMRulesObject, Outable, Serializable

All Known Subinterfaces:

IReadAccessor.Standalone, IReadWriteAccessor

All Known Implementing Classes:

Abs, AbstractConditionWrapperAccessor, AbstractExecutableWrapperAccessor, AbstractMapAccessor, AbstractPropertyCheckAccessor, AbstractReadAccessor, AbstractReadSourceAccessor, Average, DefaultVariablesManager.AbstractVariableAccessor, DefaultVariablesManager.Date, DefaultVariablesManager.DateTime, DefaultVariablesManager.Now, DefaultVariablesManager.NullValue, DefaultVariablesManager.Readbase, DefaultVariablesManager.RootReadbase, DefaultVariablesManager.RootWritebase, DefaultVariablesManager.RulesetName, DefaultVariablesManager.Time, DefaultVariablesManager.Writebase, Divide, Jdk8VariablesManager.Jdk8Date, Jdk8VariablesManager.Jdk8DateTime, Jdk8VariablesManager.Jdk8Now, Jdk8VariablesManager.Jdk8Time, MArithmeticAccessor, MAvailableAccessor, MCastAccessor, MCoalesceAccessor, MConcatenateAccessor, MConditionsCountAccessor, MConditionWrapperAccessor, MCountAccessor, MDateDiffAccessor, MDateManipulationAccessor, MDefinedAccessor, MExecutableWrapperAccessor, MFilterAccessor, MFormatAccessor, MIterateAccessor, MMapEntriesAccessor, MMapKeysAccessor, MMapValuesAccessor, MMinMaxAccessor, MMinMaxAccessor.Max, MMinMaxAccessor.Min, MNewInstanceAccessor, MNullIfEmptyAccessor, Mod, MPropertyAccessor, MSearchAccessor, MSingleMathOperation, MSizeAccessor, MSplitAccessor, MSubPartAccessor, MTernaryAccessor, Multiply, MValueAccessor, MValuesAccessor, MVariablePropertyAccessor, Pow, Round, Subtract, Sum

public interface IReadAccessor
extends IAccessor

An object which gets whatever value. Compilation methods allows to ask for a precise object type. The Accessor will do everything possible to transform original values in order to conform to what is asked. Note that ALL implementations have to be thread safe for execution.

Nested Class Summary

Nested Classes

Modifier and Type	Interface and Description
static interface	IReadAccessor.Standalone Annotating a read accessor with the Standalone interface just points out that this particular accessor may have side effects and should be able to be called in a standalone way, i.e. ignoring its returing value.

Method Summary

Modifier and Type	Method and Description
IReadAccessor	clone() Clones the Accessor.
void	compileRead(ICompilationContext ctxt) Compiles this accessor to retrieve a value or a Collection, with no constraint.
void	compileRead(ICompilationContext ctxt, Class<?> expectedType) Compiles this accessor to retrieve a value or a Collection, for witch generic type should be automatically detected if possible.
<G,C extends Collection<G>> void	compileRead(ICompilationContext ctxt, Class<C> expectedType, Class<G> expectedGenericType) Compiles this accessor to retrieve a collection, for witch generic type should be automatically detected if not provided and possible.
void	compileRead(ICompilationContext ctxt, IAccessor accessor) Compiles this accessor to retrieve a value or a Collection, in order to conform to what the provided one awaits for.
Object	get(IExecutionContext ctxt) Gets the value.
CostInfo	getEstimatedReadCost(ICompilationContext ctxt) Estimates the reading complexity, to allow callers to optimize calls.
boolean	isConstantValue() Tells if this accessor returns a constant value for all executions.
boolean	isShouldBeWrappedToConstantValue() Tells if this accessor should be wrapped into a constant value for optimization.
boolean	isShouldIterate() If this iterator is dedicated to iterate over values, then it should be precised.

Methods inherited from interface com.massa.mrules.accessor.IAccessor

getGenericCollectionType, getGenericTypes, getType

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

getImplementationId, getInternalCacheIdentifier, isCacheUsed, isInternalCacheIdentifierNeeded, optimize, resetCachedData, setInternalCacheIdentifier, wasRegistered

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

getDebugInfo, getDescription, getName, setDebugInfo, setDescription, setName

Methods inherited from interface com.massa.mrules.util.out.Outable

toString

Method Detail

compileRead

void compileRead(ICompilationContext ctxt)
          throws MRuleValidationException

Compiles this accessor to retrieve a value or a Collection, with no constraint.

Parameters:

ctxt - Compilation context.

Throws:

MRuleValidationException - if validation problem detected.

compileRead

void compileRead(ICompilationContext ctxt,
                 IAccessor accessor)
          throws MRuleValidationException

Compiles this accessor to retrieve a value or a Collection, in order to conform to what the provided one awaits for.

Parameters:

ctxt - Compilation context.

accessor - Compilation base.

Throws:

MRuleValidationException - if validation problem detected.

compileRead

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

Compiles this accessor to retrieve a value or a Collection, for witch generic type should be automatically detected if possible.

Parameters:

ctxt - Compilation context.

expectedType - If any type is expected. Null if none.

Throws:

MRuleValidationException - if validation problem detected.

compileRead

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

Compiles this accessor to retrieve a collection, for witch generic type should be automatically detected if not provided and possible.

Parameters:

ctxt - Compilation context.

expectedType - If any specific implem is expected for the collection. Null (or "Collection.class") if none.

expectedGenericType - If any generic type is expected for the collection. Null if none.

Throws:

MRuleValidationException - if validation problem detected.

getEstimatedReadCost

CostInfo getEstimatedReadCost(ICompilationContext ctxt)
                       throws MRuleValidationException

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.

get

Object get(IExecutionContext ctxt)
    throws MAccessorException

Gets the value. Automatic cast might be done according to specified expected types.

Parameters:

ctxt - Compilation context.

Returns:

Result

Throws:

MAccessorException

isShouldIterate

boolean isShouldIterate()

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.

clone

IReadAccessor clone()

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

Specified by:

clone in interface IAccessor

Specified by:

clone in interface IAddon

Specified by:

clone in interface IMRulesObject

isConstantValue

boolean isConstantValue()

Tells if this accessor returns a constant value for all executions.

Since:

1.5.0

isShouldBeWrappedToConstantValue

boolean isShouldBeWrappedToConstantValue()

Tells if this accessor should be wrapped into a constant value for optimization.

Since:

1.5.0