89 lines
3.9 KiB
C#
89 lines
3.9 KiB
C#
|
|
|||
|
|
using System;
|
|||
|
|
using System.Linq.Expressions;
|
|||
|
|
|
|||
|
|
namespace MyCode.Project.Infrastructure
|
|||
|
|
{
|
|||
|
|
/// <summary>
|
|||
|
|
/// Represents the base class for specifications.
|
|||
|
|
/// </summary>
|
|||
|
|
/// <typeparam name="T">The type of the object to which the specification is applied.</typeparam>
|
|||
|
|
public abstract class Specification<T> : ISpecification<T>
|
|||
|
|
{
|
|||
|
|
#region Public Methods
|
|||
|
|
/// <summary>
|
|||
|
|
/// Evaluates a LINQ expression to its corresponding specification.
|
|||
|
|
/// </summary>
|
|||
|
|
/// <param name="expression">The LINQ expression to be evaluated.</param>
|
|||
|
|
/// <returns>The specification which represents the same semantics as the given LINQ expression.</returns>
|
|||
|
|
public static Specification<T> Eval(Expression<Func<T, bool>> expression)
|
|||
|
|
{
|
|||
|
|
return new ExpressionSpecification<T>(expression);
|
|||
|
|
}
|
|||
|
|
#endregion
|
|||
|
|
|
|||
|
|
#region ISpecification<T> Members
|
|||
|
|
/// <summary>
|
|||
|
|
/// Returns a <see cref="System.Boolean"/> value which indicates whether the specification
|
|||
|
|
/// is satisfied by the given object.
|
|||
|
|
/// </summary>
|
|||
|
|
/// <param name="obj">The object to which the specification is applied.</param>
|
|||
|
|
/// <returns>True if the specification is satisfied, otherwise false.</returns>
|
|||
|
|
public virtual bool IsSatisfiedBy(T obj)
|
|||
|
|
{
|
|||
|
|
return this.GetExpression().Compile()(obj);
|
|||
|
|
}
|
|||
|
|
/// <summary>
|
|||
|
|
/// Combines the current specification instance with another specification instance
|
|||
|
|
/// and returns the combined specification which represents that both the current and
|
|||
|
|
/// the given specification must be satisfied by the given object.
|
|||
|
|
/// </summary>
|
|||
|
|
/// <param name="other">The specification instance with which the current specification
|
|||
|
|
/// is combined.</param>
|
|||
|
|
/// <returns>The combined specification instance.</returns>
|
|||
|
|
public ISpecification<T> And(ISpecification<T> other)
|
|||
|
|
{
|
|||
|
|
return new AndSpecification<T>(this, other);
|
|||
|
|
}
|
|||
|
|
/// <summary>
|
|||
|
|
/// Combines the current specification instance with another specification instance
|
|||
|
|
/// and returns the combined specification which represents that either the current or
|
|||
|
|
/// the given specification should be satisfied by the given object.
|
|||
|
|
/// </summary>
|
|||
|
|
/// <param name="other">The specification instance with which the current specification
|
|||
|
|
/// is combined.</param>
|
|||
|
|
/// <returns>The combined specification instance.</returns>
|
|||
|
|
public ISpecification<T> Or(ISpecification<T> other)
|
|||
|
|
{
|
|||
|
|
return new OrSpecification<T>(this, other);
|
|||
|
|
}
|
|||
|
|
/// <summary>
|
|||
|
|
/// Combines the current specification instance with another specification instance
|
|||
|
|
/// and returns the combined specification which represents that the current specification
|
|||
|
|
/// should be satisfied by the given object but the specified specification should not.
|
|||
|
|
/// </summary>
|
|||
|
|
/// <param name="other">The specification instance with which the current specification
|
|||
|
|
/// is combined.</param>
|
|||
|
|
/// <returns>The combined specification instance.</returns>
|
|||
|
|
public ISpecification<T> AndNot(ISpecification<T> other)
|
|||
|
|
{
|
|||
|
|
return new AndNotSpecification<T>(this, other);
|
|||
|
|
}
|
|||
|
|
/// <summary>
|
|||
|
|
/// Reverses the current specification instance and returns a specification which represents
|
|||
|
|
/// the semantics opposite to the current specification.
|
|||
|
|
/// </summary>
|
|||
|
|
/// <returns>The reversed specification instance.</returns>
|
|||
|
|
public ISpecification<T> Not()
|
|||
|
|
{
|
|||
|
|
return new NotSpecification<T>(this);
|
|||
|
|
}
|
|||
|
|
/// <summary>
|
|||
|
|
/// Gets the LINQ expression which represents the current specification.
|
|||
|
|
/// </summary>
|
|||
|
|
/// <returns>The LINQ expression.</returns>
|
|||
|
|
public abstract Expression<Func<T, bool>> GetExpression();
|
|||
|
|
#endregion
|
|||
|
|
}
|
|||
|
|
}
|