# BeforeDeleteSupport.java

    package org.codefilarete.stalactite.engine.cascade;

    import java.util.function.Consumer;
    import java.util.function.Function;
    import java.util.function.Predicate;
    import java.util.stream.Collectors;

    import org.codefilarete.tool.collection.Iterables;
    import org.codefilarete.tool.function.Predicates;
    import org.codefilarete.stalactite.engine.listener.DeleteListener;

    /**
     * @author Guillaume Mary
     */
    public class BeforeDeleteSupport<TRIGGER, TARGET> implements DeleteListener<TRIGGER> {

    	private final Consumer<Iterable<TARGET>> beforeDeleteAction;

    	private final Function<TRIGGER, TARGET> targetProvider;

    	private final Predicate<TARGET> targetFilter;

    	public BeforeDeleteSupport(Consumer<Iterable<TARGET>> beforeDeleteAction, Function<TRIGGER, TARGET> targetProvider) {
    		this(beforeDeleteAction, targetProvider, Predicates.acceptAll());
    	}

    	public BeforeDeleteSupport(Consumer<Iterable<TARGET>> beforeDeleteAction, Function<TRIGGER, TARGET> targetProvider, Predicate<TARGET> targetFilter) {
    		this.beforeDeleteAction = beforeDeleteAction;
    		this.targetProvider = targetProvider;
    		this.targetFilter = targetFilter;
    	}

    	@Override
    	public void beforeDelete(Iterable<? extends TRIGGER> entities) {
    		beforeDeleteAction.accept(Iterables.stream(entities).map(targetProvider).filter(targetFilter).collect(Collectors.toList()));
    	}
    }