/*
* This project is licensed under the MIT license. Module model-view-viewmodel is using ZK framework licensed under LGPL (see lgpl-3.0.txt).
*
* The MIT License
* Copyright © 2014-2022 Ilkka Seppälä
*
* Permission is hereby granted, free of charge, to any person obtaining a copy
* of this software and associated documentation files (the "Software"), to deal
* in the Software without restriction, including without limitation the rights
* to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
* copies of the Software, and to permit persons to whom the Software is
* furnished to do so, subject to the following conditions:
*
* The above copyright notice and this permission notice shall be included in
* all copies or substantial portions of the Software.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
* AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
* OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
* THE SOFTWARE.
*/
package com.iluwatar.roleobject;
import static com.iluwatar.roleobject.Role.BORROWER;
import static com.iluwatar.roleobject.Role.INVESTOR;
import lombok.extern.slf4j.Slf4j;
/**
* The Role Object pattern suggests to model context-specific views of an object as separate role
* objects which are dynamically attached to and removed from the core object. We call the resulting
* composite object structure, consisting of the core and its role objects, a subject. A subject
* often plays several roles and the same role is likely to be played by different subjects. As an
* example consider two different customers playing the role of borrower and investor, respectively.
* Both roles could as well be played by a single {@link Customer} object. The common superclass for
* customer-specific roles is provided by {@link CustomerRole}, which also supports the {@link
* Customer} interface.
*
* The {@link CustomerRole} class is abstract and not meant to be instantiated.
* Concrete subclasses of {@link CustomerRole}, for example {@link BorrowerRole} or {@link
* InvestorRole}, define and implement the interface for specific roles. It is only these subclasses
* which are instantiated at runtime. The {@link BorrowerRole} class defines the context-specific
* view of {@link Customer} objects as needed by the loan department. It defines additional
* operations to manage the customer’s credits and securities. Similarly, the {@link InvestorRole}
* class adds operations specific to the investment department’s view of customers. A client like
* the loan application may either work with objects of the {@link CustomerRole} class, using the
* interface class {@link Customer}, or with objects of concrete {@link CustomerRole} subclasses.
* Suppose the loan application knows a particular {@link Customer} instance through its {@link
* Customer} interface. The loan application may want to check whether the {@link Customer} object
* plays the role of Borrower. To this end it calls {@link Customer#hasRole(Role)} with a suitable
* role specification. For the purpose of our example, let’s assume we can name roles with enum. If
* the {@link Customer} object can play the role named “Borrower,” the loan application will ask it
* to return a reference to the corresponding object. The loan application may now use this
* reference to call Borrower-specific operations.
*/
@Slf4j
public class ApplicationRoleObject {
/**
* Main entry point.
*
* @param args program arguments
*/
public static void main(String[] args) {
var customer = Customer.newCustomer(BORROWER, INVESTOR);
LOGGER.info(" the new customer created : {}", customer);
var hasBorrowerRole = customer.hasRole(BORROWER);
LOGGER.info(" customer has a borrowed role - {}", hasBorrowerRole);
var hasInvestorRole = customer.hasRole(INVESTOR);
LOGGER.info(" customer has an investor role - {}", hasInvestorRole);
customer.getRole(INVESTOR, InvestorRole.class)
.ifPresent(inv -> {
inv.setAmountToInvest(1000);
inv.setName("Billy");
});
customer.getRole(BORROWER, BorrowerRole.class)
.ifPresent(inv -> inv.setName("Johny"));
customer.getRole(INVESTOR, InvestorRole.class)
.map(InvestorRole::invest)
.ifPresent(LOGGER::info);
customer.getRole(BORROWER, BorrowerRole.class)
.map(BorrowerRole::borrow)
.ifPresent(LOGGER::info);
}
}