/// <summary>
/// Returns a specification that joins both specified specifications together using
/// the OR operator.
/// </summary>
/// <typeparam name="T">The entity type.</typeparam>
/// <param name="specification1">The first specification.</param>
/// <param name="specification2">The second specification.</param>
/// <returns>A query specification.</returns>
public static QuerySpecification <T> Or <T>(this QuerySpecification <T> specification1, QuerySpecification <T> specification2)
{
var adhocSpec1 = new AdHoc <T>(specification1.MatchingCriteria);
var adhocSpec2 = new AdHoc <T>(specification2.MatchingCriteria);
InvocationExpression invokedExpr = Expression.Invoke(adhocSpec2.MatchingCriteria, adhocSpec1.MatchingCriteria.Parameters.Cast <Expression>());
Expression <Func <T, bool> > dynamicClause = Expression.Lambda <Func <T, bool> >(Expression.OrElse(adhocSpec1.MatchingCriteria.Body, invokedExpr), adhocSpec1.MatchingCriteria.Parameters);
return(new AdHoc <T>(dynamicClause));
}
/// <summary>
/// Returns a specification that joins both specified specifications together using
/// the OR operator.
/// </summary>
/// <typeparam name="T">The entity type.</typeparam>
/// <param name="specification1">The first specification.</param>
/// <param name="specification2">The second specification.</param>
/// <returns>A query specification.</returns>
public static QuerySpecification <T> Or <T>(this QuerySpecification <T> specification1,
QuerySpecification <T> specification2)
{
InvocationExpression invokedExpr = Expression.Invoke(specification2.MatchingCriteria !,
specification1.MatchingCriteria !.Parameters);
Expression <Func <T, bool> > dynamicClause = Expression.Lambda <Func <T, bool> >(
Expression.OrElse(specification1.MatchingCriteria !.Body, invokedExpr),
specification1.MatchingCriteria !.Parameters);
return(new AdHoc <T>(dynamicClause));
}
/// <summary>
/// Returns a specification that joins both specified specifications together using
/// the AND operator.
/// </summary>
/// <typeparam name="T">The entity type.</typeparam>
/// <param name="specification1">The first specification.</param>
/// <param name="specification2">The second specification.</param>
/// <returns>A query specification.</returns>
public static QuerySpecification <T> And <T>(this QuerySpecification <T> specification1,
QuerySpecification <T> specification2)
{
if (specification1 == null)
{
throw new ArgumentNullException(nameof(specification1));
}
if (specification2 == null)
{
throw new ArgumentNullException(nameof(specification2));
}
InvocationExpression invokedExpr =
Expression.Invoke(specification2.MatchingCriteria !, specification1.MatchingCriteria !.Parameters);
Expression <Func <T, bool> > dynamicClause = Expression.Lambda <Func <T, bool> >(
Expression.AndAlso(specification1.MatchingCriteria !.Body, invokedExpr),
specification1.MatchingCriteria !.Parameters);
return(new AdHoc <T>(dynamicClause));
}
