// Licensed to the .NET Foundation under one or more agreements.
// The .NET Foundation licenses this file to you under the MIT license.
 
namespace Microsoft.AspNetCore.Mvc.Routing;
 
/// <summary>
/// <para>
/// An attribute which specifies a required route value for an action or controller.
/// </para>
/// <para>
/// When placed on an action, the route data of a request must match the expectations of the required route data
/// in order for the action to be selected. All other actions without a route value for the given key cannot be
/// selected unless the route data of the request does omits a value matching the key.
/// See <see cref="IRouteValueProvider"/> for more details and examples.
/// </para>
/// <para>
/// When placed on a controller, unless overridden by the action, the constraint applies to all
/// actions defined by the controller.
/// </para>
/// </summary>
[AttributeUsage(AttributeTargets.Class | AttributeTargets.Method, AllowMultiple = true, Inherited = true)]
public abstract class RouteValueAttribute : Attribute, IRouteValueProvider
{
    /// <summary>
    /// Creates a new <see cref="RouteValueAttribute"/>.
    /// </summary>
    /// <param name="routeKey">The route value key.</param>
    /// <param name="routeValue">The expected route value.</param>
    protected RouteValueAttribute(
        string routeKey,
        string routeValue)
    {
        ArgumentNullException.ThrowIfNull(routeKey);
        ArgumentNullException.ThrowIfNull(routeValue);
 
        RouteKey = routeKey;
        RouteValue = routeValue;
    }
 
    /// <inheritdoc />
    public string RouteKey { get; }
 
    /// <inheritdoc />
    public string RouteValue { get; }
}