com.artemis.injection

Class FieldHandler

java.lang.Object

com.artemis.injection.FieldHandler

public class FieldHandler
extends Object

FieldHandler provides dependency-values to an Injector by sequentially iterating over a list of registered FieldResolver.

The method resolve(Object, Class, Field) will return the first non-null value provided by FieldResolver.resolve(Object, Class, Field), or null if no resolver returned a valid value.

During World construction, after systems and managers have been created, initialize(World, Map) will be called for each registered FieldResolver

If FieldResolver implements UseInjectionCache, UseInjectionCache.setCache(InjectionCache) will be called prior to FieldResolver.initialize(World) being called, availing the InjectionCache used by this handler.

Author:

Snorre E. Brekke

Field Summary

Fields

Modifier and Type	Field and Description
protected Bag<FieldResolver>	fieldResolvers

Constructor Summary

Constructors

Constructor and Description
FieldHandler(InjectionCache cache) Constructs a ned FieldHandler with an ArtemisFieldResolver and WiredFieldResolver already registered, which can resolve ComponentMapper, BaseSystem and Manager types registered in the World Wire.
FieldHandler(InjectionCache cache, Bag<FieldResolver> fieldResolvers) Constructs a new FieldHandler with the provided fieldResolvers.

Method Summary

Modifier and Type	Method and Description
void	addFieldResolver(FieldResolver fieldResolver) Adds a FieldResolver to this handler.
Bag<FieldResolver>	getFieldResolvers()
void	initialize(World world, Map<String,Object> injectables) During World construction, after systems and managers have been created, initialize(World, Map) will be called for each registered FieldResolver
Object	resolve(Object target, Class<?> fieldType, Field field) Returns the first non-null value provided by FieldResolver.resolve(Object, Class, Field), or null if no resolver returned a valid value.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Field Detail

fieldResolvers

protected Bag<FieldResolver> fieldResolvers

Constructor Detail

FieldHandler

public FieldHandler(InjectionCache cache,
                    Bag<FieldResolver> fieldResolvers)

Constructs a new FieldHandler with the provided fieldResolvers. This constructor should be used when full control over the FieldResolver order is required.

For Artemis to function correctly, ArtemisFieldResolver should be added somewhere in the bag, or added via addFieldResolver(FieldResolver) prior to world construction.

Parameters:

cache - used for better reflection-speed.

fieldResolvers - bag of fieldresolver this FieldHandler should use.

See Also:

ArtemisFieldResolver

FieldHandler

public FieldHandler(InjectionCache cache)

Constructs a ned FieldHandler with an ArtemisFieldResolver and WiredFieldResolver already registered, which can resolve ComponentMapper, BaseSystem and Manager types registered in the World Wire.

Parameters:

cache - used for better reflection-speed.

See Also:

ArtemisFieldResolver

Method Detail

initialize

public void initialize(World world,
                       Map<String,Object> injectables)

During World construction, after systems and managers have been created, initialize(World, Map) will be called for each registered FieldResolver

If FieldResolver implements UseInjectionCache, UseInjectionCache.setCache(InjectionCache) will be called prior to FieldResolver.initialize(World) being called, availing the InjectionCache used by this handler.

Parameters:

world - the world this FieldHandler is being used for

Throws:

WorldConfigurationException - when injector has no way to deal with injectables.

resolve

public Object resolve(Object target,
                      Class<?> fieldType,
                      Field field)

Returns the first non-null value provided by FieldResolver.resolve(Object, Class, Field), or null if no resolver returned a valid value.

Parameters:

fieldType - class of the field

field - field for which a value should be resolved

Returns:

a non-null value if any FieldResolver could provide an instance for the field, null if the field could not be resolved

addFieldResolver

public final void addFieldResolver(FieldResolver fieldResolver)

Adds a FieldResolver to this handler. Resolvers added first, will be used first for resolving fields, so the order of add operations is significant.

Parameters:

fieldResolver - is added to this FieldHandler fieldresolver-list

getFieldResolvers

public Bag<FieldResolver> getFieldResolvers()