How to get response body using custom middle ware?

Question

problem

How to get response body on invoke next context using custom middle ware ??

After reach to line of await _next.Invoke(context) from debug;

not return json data from action result getusermenu

[HttpGet(Contracts.ApiRoutes.Security.GetUserMenus)]
 public IActionResult GetUserMenu(string userId)
        {
            string strUserMenus = _SecurityService.GetUserMenus(userId);
            return Ok(strUserMenus);
        }

I need to get response body from action result above

header :
key : Authorization
value : ehhhheeedff .

my code i try it :

public async Task InvokeAsync(HttpContext context, DataContext dataContext)
        {


            // than you logic to validate token              

            if (!validKey)
            {
                context.Response.StatusCode = (int)HttpStatusCode.Forbidden;
                await context.Response.WriteAsync("Invalid Token");
            }
            //if valid than next middleware Invoke
            else
            {
                await _next.Invoke(context);
// i need after that get result on last of thread meaning return data of usermenu

            }
        }
    }
 public static class TokenExtensions
    {
        public static IApplicationBuilder UseTokenAuth(this IApplicationBuilder builder)
        {
              return builder.UseMiddleware<TokenValidateMiddleware>();

        }
    }


          [no return data from access token][1]

https://i.stack.imgur.com/PHUMs.png

if(validtoken)
{
continue display getusermenuaction and show result

}

when valid token it return data like below on browser googlechrom

[
  {
    "form_name": "FrmAddPrograms",
    "title": "Adding Screens",
    "url": "",
    "permissions": {
      "Insert": "True",
      "Edit": "True",
      "Read": "True",
      "Delete": "True",
      "Print": "True",
      "Excel": "False",
      "RecordList": "False"
    }
  },

but on my app browser return not valid token

What kind of response are you expecting? Calling next on the request delegate just forwards the request to the next middleware in line or the request reaches a backstop handler provided by ASP.NET Core when it creates the pipeline, which sends the request back along the pipeline in the other direction. — Dennis VW, Sep 15 '19 at 08:43
forword request to nextmiddleware line and show response body — ahmed abed elaziz, Sep 16 '19 at 05:06

score 0 · Answer 1 · answered Sep 16 '19 at 05:25

0

Try to get response body in custom middleware using below code:

public class CustomMiddleware
{
    private readonly RequestDelegate next;

    public CustomMiddleware(RequestDelegate next)
    {
        this.next = next;
    }

    public async Task Invoke(HttpContext context)
    {

        if (!validKey)
        {
            context.Response.StatusCode = (int)HttpStatusCode.Forbidden;
            await context.Response.WriteAsync("Invalid Token");
        }
        //if valid than next middleware Invoke
        else
        {
            Stream originalBody = context.Response.Body;

            try
            {
                using (var memStream = new MemoryStream())
                {
                    context.Response.Body = memStream;

                    await next(context);

                    memStream.Position = 0;
                    string responseBody = new StreamReader(memStream).ReadToEnd();//get response body here after next.Invoke()

                    memStream.Position = 0;
                    await memStream.CopyToAsync(originalBody);
                }

            }
            finally
            {
                context.Response.Body = originalBody;
            }
        }          
    }
}

answered Sep 16 '19 at 05:25

Ryan

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thank you for reply still return invalid token on browser although from debug it reach to isvalid =true and and from debug get value of string responseBody as i need and on postman show result correct but in browser show invalid token message this message i write on code on line of invalid token but why this message shown although code not hit invalid token – ahmed abed elaziz Sep 16 '19 at 07:47
@ahmed abed elaziz Do you mean the token is valid and the code `await context.Response.WriteAsync("Invalid Token");` never be hit when you add break points,but the browser output the error message?The token needs to start with `Bearer xxxxx`.Do you add `app.UseTokenAuth` just before `app.UseMvc`?Based on your code without token It works well,I think it is related to your token validation issure. – Ryan Sep 16 '19 at 08:12
on configure on startup.cs class i do app.UseMiddleware(); app.UseHttpsRedirection(); app.UseAuthentication(); app.UseCors("CorsData"); app.UseMvc(); but according to Bearer i dont start because id ont know can you tell me how – ahmed abed elaziz Sep 16 '19 at 08:19
i already use app.class of middleware have app.tokenauth before app.usemvc but bearer cannot know any thing about that can you tell me how to start with bearer – ahmed abed elaziz Sep 16 '19 at 08:25
@ahmed abed elaziz Oh,forget that if you works well using postman by the same token...But JWT authentication itself will authenticate the token and return the result,there's no need to write a custom middleware.Again, it seems not related to your question title.You could ask a new thread and post necessary code. – Ryan Sep 16 '19 at 08:55
can you clear more your answer mean start with bearer or not this is what i need only – ahmed abed elaziz Sep 16 '19 at 09:14
@ahmed abed elaziz No,If you do not use Bearer token, then you do not need to.https://stackoverflow.com/questions/40375508/whats-the-difference-between-jwts-and-bearer-token – Ryan Sep 17 '19 at 01:34
thank you for reply result of your code above show success on postman but not show on my browser why . my browser used is google chrome browser – ahmed abed elaziz Sep 19 '19 at 03:52
@ahmed abed elaziz how do you send request in your browser?Does it have a valid token and come into the `if (!validKey)`? – Ryan Sep 19 '19 at 05:32

How to get response body using custom middle ware?

1 Answers1