Path.Combine for URLs?

Question

Path.Combine is handy, but is there a similar function in the .NET framework for URLs?

I'm looking for syntax like this:

Url.Combine("http://MyUrl.com/", "/Images/Image.jpg")

which would return:

"http://MyUrl.com/Images/Image.jpg"

Answer 1

Here's Microsoft's (OfficeDev PnP) method UrlUtility.Combine:

    const char PATH_DELIMITER = '/';

    /// <summary>
    /// Combines a path and a relative path.
    /// </summary>
    /// <param name="path"></param>
    /// <param name="relative"></param>
    /// <returns></returns>
    public static string Combine(string path, string relative) 
    {
        if(relative == null)
            relative = String.Empty;

        if(path == null)
            path = String.Empty;

        if(relative.Length == 0 && path.Length == 0)
            return String.Empty;

        if(relative.Length == 0)
            return path;

        if(path.Length == 0)
            return relative;

        path = path.Replace('\\', PATH_DELIMITER);
        relative = relative.Replace('\\', PATH_DELIMITER);

        return path.TrimEnd(PATH_DELIMITER) + PATH_DELIMITER + relative.TrimStart(PATH_DELIMITER);
    }

Source: GitHub

Answer 2

A simple one liner:

public static string Combine(this string uri1, string uri2) => $"{uri1.TrimEnd('/')}/{uri2.TrimStart('/')}";

Inspired by @Matt Sharpe's answer.

Answer 3

Both of these work:

  Uri final = new Uri(Regex.Replace(baseUrl + "/" + relativePath, "(?<!http:)/{2,}", "/"));

Or

  Uri final =new Uri(string.Format("{0}/{1}", baseUrl.ToString().TrimEnd('/'), relativePath.ToString().TrimStart('/')));

I.e. if

baseUrl = "http://tesrurl.test.com/Int18"

and

relativePath = "To_Folder"

output = http://tesrurl.test.com/Int18/To_Folder

Some errors will appear for the code below:

 // If you use the below code, some issues will be there in the final URI
 Uri final = new Uri(baseUrl, relativePath);

Answer 4

An easy way to combine them and ensure it's always correct is:

string.Format("{0}/{1}", Url1.Trim('/'), Url2);

Answer 5

Uri has a constructor that should do this for you: new Uri(Uri baseUri, string relativeUri)

Here's an example:

Uri baseUri = new Uri("http://www.contoso.com");
Uri myUri = new Uri(baseUri, "catalog/shownew.htm");

Note from editor: Beware, this method does not work as expected. It can cut part of baseUri in some cases. See comments and other answers.

Answer 6

Witty example, Ryan, to end with a link to the function. Well done.

One recommendation Brian: if you wrap this code in a function, you may want to use a UriBuilder to wrap the base URL prior to the TryCreate call.

Otherwise, the base URL MUST include the scheme (where the UriBuilder will assume http://). Just a thought:

public string CombineUrl(string baseUrl, string relativeUrl) {
    UriBuilder baseUri = new UriBuilder(baseUrl);
    Uri newUri;

    if (Uri.TryCreate(baseUri.Uri, relativeUrl, out newUri))
        return newUri.ToString();
    else
        throw new ArgumentException("Unable to combine specified url values");
}