package com.dooapp.gaedo.finders.id;
import java.util.Collection;
import java.util.List;
import com.dooapp.gaedo.finders.FieldInformer;
import com.dooapp.gaedo.finders.FinderCrudService;
import com.dooapp.gaedo.finders.Informer;
import com.dooapp.gaedo.finders.QueryBuilder;
import com.dooapp.gaedo.finders.QueryExpression;
import com.dooapp.gaedo.finders.expressions.Expressions;
import com.dooapp.gaedo.properties.Property;
/**
* Helper class simplifying the writing of an IdBasedService by providing some helper methods
* @author ndx
*
*/
public class IdBasedServiceHelper<DataType, InformerType extends Informer<DataType>> {
private List<Property> idProperties;
private FinderCrudService<DataType, InformerType> backEnd;
public IdBasedServiceHelper(List<Property> idProperties,
FinderCrudService<DataType, InformerType> backEnd) {
this.idProperties = idProperties;
this.backEnd = backEnd;
}
public DataType findById(final Object... id) {
return backEnd.find().matching(new QueryBuilder<InformerType>() {
@Override
public QueryExpression createMatchingExpression(
InformerType informer) {
QueryExpression returned = null;
for(int index=0; index<id.length; index++) {
FieldInformer fieldInformer = backEnd.getInformer().get(idProperties.get(index).getName());
QueryExpression propertyEquality = fieldInformer.equalsTo(id[index]);
if(returned==null) {
returned = propertyEquality;
} else {
returned = Expressions.and(returned, propertyEquality);
}
}
return returned;
}
}).getFirst();
}
public Collection<Property> getIdProperties() {
return idProperties;
}
public boolean assignId(DataType value, Object... id) {
for(int index=0; index<id.length; index++) {
idProperties.get(index).set(value, id[index]);
}
return true;
}
}