Dynamic Url rewrite in ASP.NET CORE - url

Question

I'm trying to rewrite a URL, and detect if a portion of the URL exists,
then process that string to finally create a final URL.
From this article, I found so far a way to replace segments of the URL using a regex.
My case is the following:
given the URL
www.whatever.com/segment1/segment2?parameter=value
I need to detect if the text "parameter=" exist in the URL and then process the value and get something like:
www.whatever.com/segment1/segment2?parameter=valueConverted
First, I tried doing something like:
var options = new RewriteOptions()
.AddRedirect("segment1/segment2/(.*)", "segment2/$1");
which worked fine but I was later asked to process the value of the parameter.
But I have not found something similar to this yet:
var options = new RewriteOptions()
.AddRewrite(#"^param=$", "param=" MethodCall(how to send value here?) );
Any guidance?

Answer 1

I found some interesting articles like this that helped me accomplish this... take a look at my final code:
public void Configure(IApplicationBuilder app ...
{
var options = new RewriteOptions()
.Add(new MyCustomRules());
}
...
public class MyCustomRules : Microsoft.AspNetCore.Rewrite.IRule
{
private int StatusCode { get; } = (int)System.Net.HttpStatusCode.MovedPermanently;
private const string PARAMETER = "parameter=";
public void ApplyRule(RewriteContext context)
{
var request = context.HttpContext.Request;
var host = request.Host;
var url = request.Path.Value;
var queryString = request.QueryString.Value;
if (queryString.Contains(PARAMETER, StringComparison.OrdinalIgnoreCase))
{
var host = request.Host;
var originalText = queryString.Split(PARAMETER)[1];
var convertedText = processText.Method(originalText);
var newUrl = request.Scheme + host.Value + request.Path + "?" + PARAMETER + convertedText;
var response = context.HttpContext.Response;
response.StatusCode = StatusCode;
response.Headers[Microsoft.Net.Http.Headers.HeaderNames.Location] = newUrl;
context.Result = RuleResult.EndResponse;
return;
}
context.Result = RuleResult.ContinueRules;
return;
}
}
UPDATE: you have to be careful about redirect Looping.