70 lines
2.6 KiB
C#
70 lines
2.6 KiB
C#
using System;
|
|
using System.Collections.Generic;
|
|
using System.Threading.Tasks;
|
|
|
|
namespace Tapeti.Helpers
|
|
{
|
|
/// <summary>
|
|
/// Helper class for executing the middleware pattern.
|
|
/// </summary>
|
|
public static class MiddlewareHelper
|
|
{
|
|
/// <summary>
|
|
/// Executes the chain of middleware synchronously, starting with the last item in the list.
|
|
/// </summary>
|
|
/// <param name="middleware">The list of middleware to run</param>
|
|
/// <param name="handle">Receives the middleware which should be called and a reference to the action which will call the next. Pass this on to the middleware.</param>
|
|
/// <param name="lastHandler">The action to execute when the innermost middleware calls next.</param>
|
|
/// <typeparam name="T"></typeparam>
|
|
public static void Go<T>(IReadOnlyList<T> middleware, Action<T, Action> handle, Action lastHandler)
|
|
{
|
|
var handlerIndex = middleware?.Count - 1 ?? -1;
|
|
if (middleware == null || handlerIndex == -1)
|
|
{
|
|
lastHandler();
|
|
return;
|
|
}
|
|
|
|
void HandleNext()
|
|
{
|
|
handlerIndex--;
|
|
if (handlerIndex >= 0)
|
|
handle(middleware[handlerIndex], HandleNext);
|
|
else
|
|
lastHandler();
|
|
}
|
|
|
|
handle(middleware[handlerIndex], HandleNext);
|
|
}
|
|
|
|
|
|
/// <summary>
|
|
/// Executes the chain of middleware asynchronously, starting with the last item in the list.
|
|
/// </summary>
|
|
/// <param name="middleware">The list of middleware to run</param>
|
|
/// <param name="handle">Receives the middleware which should be called and a reference to the action which will call the next. Pass this on to the middleware.</param>
|
|
/// <param name="lastHandler">The action to execute when the innermost middleware calls next.</param>
|
|
/// <typeparam name="T"></typeparam>
|
|
public static async Task GoAsync<T>(IReadOnlyList<T> middleware, Func<T, Func<Task>, Task> handle, Func<Task> lastHandler)
|
|
{
|
|
var handlerIndex = middleware?.Count - 1 ?? -1;
|
|
if (middleware == null || handlerIndex == -1)
|
|
{
|
|
await lastHandler();
|
|
return;
|
|
}
|
|
|
|
async Task HandleNext()
|
|
{
|
|
handlerIndex--;
|
|
if (handlerIndex >= 0)
|
|
await handle(middleware[handlerIndex], HandleNext);
|
|
else
|
|
await lastHandler();
|
|
}
|
|
|
|
await handle(middleware[handlerIndex], HandleNext);
|
|
}
|
|
}
|
|
}
|