/**
* Constructs a new MultiElementQuery instance. MultiElementQuery requires the target, the result
* and the element class being provided. It will use them for creating the result object.
*
* <p>The execution of an empty query will result in the same object being returned. No operation
* will be performed.
*
* @param elementClass A class of the components in the queried composition.
* @param targetClass A class of the queried object.
* @param resultClass A class of the result, it must be a class that can be instantiated. If it is
* not, a {@link QueryException} will be thrown during query execution.
*/
public MultiElementQuery(Class<?> elementClass, Class<?> targetClass, Class<?> resultClass) {
initialSelectors.add(InitialSelectors.all());
valueFilter = ValueFilters.any();
functions.add(QueryFunctions.<R>noOperation());
this.targetClass = targetClass;
this.elementClass = elementClass;
this.resultClass = resultClass;
}
@SuppressWarnings("unchecked")
protected void addValueFilter(IValueFilter<? super E> filter) {
valueFilter = ValueFilters.<Object>allOf(valueFilter, filter);
}
/**
* Adds a value filter that operates on a specific field of the target class to the query.
*
* @param fieldName A field name that will be used in matching.
* @param filter A value filter to add.
* @param <S> A type of the field.
* @return This query.
*/
public <S> MultiElementQuery<E, Q, R> matching(String fieldName, IValueFilter<S> filter) {
addValueFilter(ValueFilters.<E, S>fieldValue(fieldName, filter));
return this;
}
