Package org.eclipse.emfforms.bazaar

Interface Bazaar<T>

Type Parameters:

T - the type of product create by this Bazaar

All Known Implementing Classes:

BazaarImpl, ThreadSafeBazaar

public interface Bazaar<T>

A Bazaar is a flexible registry for factories to create specific objects of type T, called "product". To create a product, an arbitrary number of Vendor is queried. Vendor request certain parameters to create a product. This is queried from the BazaarContext. If a AllPermission parameters requested by a Vendor are present in the BazaarContext, a Vendor will do a Bid. The Vendor with the highest Bid will finally create a product. If two or more Vendor do the same bid, the registered Bazaar.PriorityOverlapCallBack will be notified, an arbitrary Vendor with the same Bid will create the product in this case. To transform parameter in the BazaarContext into parameters Vendors expect, you can register BazaarContextFunctions at the Bazaar.

Author:

jonas

Nested Class Summary

Nested Classes

Modifier and Type	Interface	Description
static class	Bazaar.Builder<T>	A fluent builder of Bazaars.
static interface	Bazaar.PriorityOverlapCallBack<T>	If two or more Vendors make the same bid, the registered Bazaar.PriorityOverlapCallBack will be notified, an arbitrary Vendor with the same Bid will create the product in this case.

Method Summary

Modifier and Type	Method	Description
void	addContextFunction(java.lang.String key, BazaarContextFunction contextFunction)	Adds a BazaarContextFunction to this Bazaar to exchange existing parameters to a parameter requested by a Vendor.
void	addVendor(Vendor<? extends T> vendor)	Adds a Vendor to the bazaar.
T	createProduct(BazaarContext context)	Creates a product of type T, provided by the Vendor with the highest Bid and which is statisfied by the parameters in the BazaarContext.
java.util.List<T>	createProducts(BazaarContext context)	Creates a list of products of type T, provided by Vendors which are statisfied by the parameters in the BazaarContext, ordered by their Bid.
void	removeVendor(Vendor<? extends T> vendor)	Removes a Vendor from the bazaar.
void	setPriorityOverlapCallBack(Bazaar.PriorityOverlapCallBack<? super T> priorityOverlapCallBack)	Adds a Bazaar.PriorityOverlapCallBack, see Bazaar.PriorityOverlapCallBack.

Method Detail

addVendor

void addVendor(Vendor<? extends T> vendor)

Adds a Vendor to the bazaar. Will be queried if a product is requested, the best fitting will create the product. Has no effect if the vendor is already present in this bazaar.

Parameters:

vendor - the Vendor

removeVendor

void removeVendor(Vendor<? extends T> vendor)

Removes a Vendor from the bazaar. Has no effect if the vendor is not present in this bazaar.

Parameters:

vendor - the Vendor to remove

addContextFunction

void addContextFunction(java.lang.String key,
                        BazaarContextFunction contextFunction)

Adds a BazaarContextFunction to this Bazaar to exchange existing parameters to a parameter requested by a Vendor.

Parameters:

key - the key of a requested parameter, which can be exchanged from other available parameters in the BazaarContext by this BazaarContextFunction

contextFunction - the BazaarContextFunction being able to exchange to the requested parameter

createProduct

T createProduct(BazaarContext context)

Creates a product of type T, provided by the Vendor with the highest Bid and which is statisfied by the parameters in the BazaarContext. In case of tied bids, the Bazaar.PriorityOverlapCallBack if one is set will be notified of which vendor is chosen to break the tie. Note that during the bidding process, ties may have to be broken in this way that are later defeated by a higher bid.

Parameters:

context - the BazaarContext, which is used to provide requested parameters for Vendor

Returns:

the product provided by the best Vendor

See Also:

setPriorityOverlapCallBack(PriorityOverlapCallBack)

createProducts

java.util.List<T> createProducts(BazaarContext context)

Creates a list of products of type T, provided by Vendors which are statisfied by the parameters in the BazaarContext, ordered by their Bid. Ties are not broken as all bids are successful and are used only for ordering.

Parameters:

context - the BazaarContext, which is used to provide requested parameters for Vendor

Returns:

a list of products ordered by the highest Bid

setPriorityOverlapCallBack

void setPriorityOverlapCallBack(Bazaar.PriorityOverlapCallBack<? super T> priorityOverlapCallBack)

Adds a Bazaar.PriorityOverlapCallBack, see Bazaar.PriorityOverlapCallBack.

Parameters:

priorityOverlapCallBack - a PriorityOverlapCallBack