FluentUriBuilder

A safer and more readable way to build URI's in .NET

Quick example

To build this new URI:

ftp://user:[email protected]:888/path/to/file?param1=val1&param2=a%23value%26with%40weird%3fcharacters#fragment

Write:

var uri = FluentUriBuilder.Create()
    .Scheme(UriScheme.Ftp)
    .Credentials("user", "password")
    .Host("example.com")
    .Port(888)
    .Path("path/to/file")
    .QueryParams(new {
        param1 = "val1",
        param2 = "a#value&with@weird?characters"
    })
    .Fragment("fragment")
    .ToString();

Rationale

You often see code that creates URI's using simple string concatenation or format strings:

var valueWithWeirdCharacters = "a#value&with@weird?characters";
var badUri1 = "http://example.com/path?param1=" + valueWithWeirdCharacters + "&param2=asdf";
var badUri2 = string.Format("http://example.com/path?param1={0}&param2=asdf", valueWithWeirdCharacters);

The result is an invalid URI because the value of param1 is not escaped:

"http://example.com/path?param1=a#value&with@weird?characters&param2=asdf"

One alternative is to escape each value using Uri.EscapeDataString:

var correctUri = "http://example.com/path?param1=" +
    Uri.EscapeDataString(valueWithWeirdCharacters) +
	"&param2=asdf";

But this quickly gets ugly when you have a lot of arguments, and it is easy to forget.

Enter System.UriBuilder:

var valueWithWeirdCharacters = "a#value&with@weird?characters";
var uriBuilder = new UriBuilder("http://example.com/path");
var parameters = HttpUtility.ParseQueryString(string.Empty);

parameters["param1"] = valueWithWeirdCharacters;
parameters["param2"] = "asdf";

uriBuilder.Query = parameters.ToString();

var correctUri = uriBuilder.AbsoluteUri;

This is correct, but also the most complicated and unreadable of all of the above examples. This is why I created FluentUriBuilder: to allow creating URI's in a safe and readable way:

var valueWithWeirdCharacters = "a#value&with@weird?characters";
var uri = FluentUriBuilder
    .From("http://example.com/path")
	.QueryParam("param1", valueWithWeirdCharacters)
	.QueryParam("param2", "asdf")
	.ToString();

More Examples

Query parameters can also be specified using an IDictionary<TKey, TValue>:

var params = new Dictionary<string, string> {
	{ "user", "averagejoe236" },
	{ "apiKey", "af43af43rcfaf34xqf" }
};

var uri = FluentUriBuilder.Create()
    .Scheme(UriScheme.Http)
	.Host("facebook.com")
	.Path("posts")
	.QueryParams(params)
	.ToString();

Or one by one, by calling .QueryParam("key", "value") repeatedly:

var uri = FluentUriBuilder.Create()
    .Scheme(UriScheme.Http)
	.Host("google.com")
	.Path("/")
	.QueryParam("q", "FluentUriBuilder")
	.QueryParam("source", "hp")
	.ToString();

The latter can be used to specify more query parameters with the same name.

To modify an existing URI:

var uri = FluentUriBuilder.From("http://example.com/somepath?foo=bar#baz")
    .Port(8080)
    .Path("/otherpath")
    .RemoveQueryParams()
    .RemoveFragment()
    .ToUri();

This example returns a System.Uri instance instead of a string because of the .ToUri() call at the end.

Framework Support

The project currently supports .NET 2.0+. .NET Core support is planned.