Itminus.Middleware 0.2.1

A Refined , Extended and Minimal Middleware System , shamelessly copied from ASP.NET Core .

The Honor Blongs to Microsoft .

Concepts

There're two key Types in the middleware system .

1. WorkDelegate<TContext>

WorkDelegate<TContext> represents a delegate which defines what to do with the TContext parameter :

Task WorkDelegate<TContext>(TContext context)

2. WorkContainer<TContext>

WorkContainer<TContext> is a container to store codes that describe how to deal with TContext in the future . We can invoke a Build() method to create a new WorkDelegate<TContext> .

Usage

1. contruct a new container WorkContainer<TContext> , such as WorkContainer<List<string> ，WorkContainer<HttpContext> ，WorkContainer<ConfigurationBuilder> ， and so on .
2. register middlewares
3. build all middlewares into a finally combined WorkDelegate<TContext>

// construct a container
var container = new WorkContainer<List<string>>();

// regsiter a middleware
container
    .Use(next =>
    {
        return async context =>
        {
            context.Add(MessageCall(1,true));
            await next(context);
            context.Add(MessageCall(1,false));
        };
    })
    // register a in-line style middleware
    .Use(async (context, next) =>
    {
        context.Add(MessageCall(3,true));
        await next();
        context.Add(MessageCall(3,false));
    });

    var d = container.Build();
    var _context = new List<string>();
    d(_context);

Branch

container
    .MapWhen( predicateTrue, next => {
        return async context => {
            context.Add(MessageCall(1, true));
            await next(context);
            context.Add(MessageCall(1, false));
        };
    })
    .MapWhen( predicateTrue, async (context,next) => {
        context.Add(MessageCall(3, true));
        await next();
        context.Add(MessageCall(3, false));
    })

Terminal

container
    // register a terminal middleware
    .Run((context) =>
    {
        context.Add(MessageCall(4,true));
        return Task.CompletedTask;
    });

Branch-Terminal

container
    .RunWhen( predicateTrue, (context) => {
        context.Add(MessageCall(7, false));
        return Task.CompletedTask;
    });