Meziantou.Framework

Getting started

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Install the package

Add the Meziantou.Framework.Uri package to a project:

dotnet package add Meziantou.Framework.Uri

The examples of this documentation omit the using directives: they need using Meziantou.Framework;, and using Microsoft.Extensions.Primitives; for the examples that use StringValues.

Match a URL against a pattern

UrlPattern.Create parses a pattern. IsMatch tests a URL, and Match returns the values of the groups:

// Create a pattern and test if a URL matches
var pattern = UrlPattern.Create("https://example.com/users/:id");
Assert.True(pattern.IsMatch("https://example.com/users/123"));

// Extract captured groups from a URL
var result = pattern.Match("https://example.com/users/456");
Assert.NotNull(result);
Assert.Equal("456", result.Pathname.Groups["id"]);

// Use wildcards to match any value
var wildcardPattern = UrlPattern.Create("https://*.example.com/*");
Assert.True(wildcardPattern.IsMatch("https://api.example.com/data"));
  • :id is a named group: it matches one path segment, and its value is in the result.
  • * is a wildcard: it matches any text.

See Matching URLs and Pattern syntax.

Read and edit a query string

QueryStringUtilities parses a query string and returns a new URL with parameters added, replaced or removed:

var query = QueryStringUtilities.ParseQuery("?author=meziantou&tag=dotnet&tag=csharp");
Assert.Equal("meziantou", query["author"].ToString());
Assert.Equal(["dotnet", "csharp"], query["tag"].ToArray());

var uri = "https://www.meziantou.net/?author=meziantou";
Assert.Equal("https://www.meziantou.net/?author=meziantou&name=value", QueryStringUtilities.AddQueryString(uri, "name", "value"));
Assert.Equal("https://www.meziantou.net/?author=john", QueryStringUtilities.AddOrReplaceQueryString(uri, "author", "john"));

// Replace the whole query string
Assert.Equal("https://www.meziantou.net/?name=value", QueryStringUtilities.SetQueryString(uri, [KeyValuePair.Create("name", (string?)"value")]));

// Remove a query string parameter
Assert.Equal("https://www.meziantou.net/", QueryStringUtilities.RemoveQueryString(uri, "author"));

See Query strings.

Compare two sites

PublicSuffixList.GetRegistrableDomain returns the part of a host name that a registrant controls, so two hosts with the same registrable domain belong to the same site:

static bool IsSameSite(string host1, string host2)
{
    var site1 = PublicSuffixList.GetRegistrableDomain(host1);
    var site2 = PublicSuffixList.GetRegistrableDomain(host2);
    return site1 is not null && site1 == site2;
}

Assert.True(IsSameSite("www.example.co.uk", "shop.example.co.uk"));
Assert.False(IsSameSite("example.co.uk", "contoso.co.uk"));

// github.io is a public suffix: two sites hosted there are different sites
Assert.False(IsSameSite("alice.github.io", "bob.github.io"));

See Public Suffix List.

Next steps