How are OwinContext.Request.Path and PathBase populated?

Question

I\'m writing my own OWIN middleware for OpenID Connect authorization code flow, based on other examples in the Katana Project.

As part of this I have to construct a coup

Answer 1

When using the construct

app.Map("/login", map => [...]

This uses

Owin.MapExtensions.Map

which constructs an instance of

Microsoft.Owin.Mapping.MapMiddleware

for the code which needs running.

The behaviour I have seen is explained in the Invoke method of this middleware:

public async Task Invoke(IDictionary<string, object> environment)
{
    IOwinContext context = new OwinContext(environment);

    PathString path = context.Request.Path;

    PathString remainingPath;
    if (path.StartsWithSegments(_options.PathMatch, out remainingPath))
    {
        // Update the path
        PathString pathBase = context.Request.PathBase;
        context.Request.PathBase = pathBase + _options.PathMatch;
        context.Request.Path = remainingPath;

        await _options.Branch(environment);

        context.Request.PathBase = pathBase;
        context.Request.Path = path;
    }
    else
    {
        await _next(environment);
    }
}

Basically the code changes the Path and PathBase before it runs the delegate (await _options.Branch(environment) ), then sets these back to the original values after execution is complete.

Hence the behaviour I had seen is explained.