# System.Text.Encodings.Web

``` diff
+namespace System.Text.Encodings.Web {
+    public abstract class HtmlEncoder : TextEncoder {
+        protected HtmlEncoder();
+        public static HtmlEncoder Default { get; }
+        public static HtmlEncoder Create(TextEncoderSettings settings);
+        public static HtmlEncoder Create(params UnicodeRange[] allowedRanges);
+    }
+    public abstract class JavaScriptEncoder : TextEncoder {
+        protected JavaScriptEncoder();
+        public static JavaScriptEncoder Default { get; }
+        public static JavaScriptEncoder UnsafeRelaxedJsonEscaping { get; }
+        public static JavaScriptEncoder Create(TextEncoderSettings settings);
+        public static JavaScriptEncoder Create(params UnicodeRange[] allowedRanges);
+    }
+    public abstract class TextEncoder {
+        protected TextEncoder();
+        public abstract int MaxOutputCharactersPerInputCharacter { get; }
+        public virtual void Encode(TextWriter output, char[] value, int startIndex, int characterCount);
+        public void Encode(TextWriter output, string value);
+        public virtual void Encode(TextWriter output, string value, int startIndex, int characterCount);
+        public virtual OperationStatus Encode(ReadOnlySpan<char> source, Span<char> destination, out int charsConsumed, out int charsWritten, bool isFinalBlock = true);
+        public virtual string Encode(string value);
+        public virtual OperationStatus EncodeUtf8(ReadOnlySpan<byte> utf8Source, Span<byte> utf8Destination, out int bytesConsumed, out int bytesWritten, bool isFinalBlock = true);
+        public unsafe abstract int FindFirstCharacterToEncode(char* text, int textLength);
+        public virtual int FindFirstCharacterToEncodeUtf8(ReadOnlySpan<byte> utf8Text);
+        public unsafe abstract bool TryEncodeUnicodeScalar(int unicodeScalar, char* buffer, int bufferLength, out int numberOfCharactersWritten);
+        public abstract bool WillEncode(int unicodeScalar);
+    }
+    public class TextEncoderSettings {
+        public TextEncoderSettings();
+        public TextEncoderSettings(TextEncoderSettings other);
+        public TextEncoderSettings(params UnicodeRange[] allowedRanges);
+        public virtual void AllowCharacter(char character);
+        public virtual void AllowCharacters(params char[] characters);
+        public virtual void AllowCodePoints(IEnumerable<int> codePoints);
+        public virtual void AllowRange(UnicodeRange range);
+        public virtual void AllowRanges(params UnicodeRange[] ranges);
+        public virtual void Clear();
+        public virtual void ForbidCharacter(char character);
+        public virtual void ForbidCharacters(params char[] characters);
+        public virtual void ForbidRange(UnicodeRange range);
+        public virtual void ForbidRanges(params UnicodeRange[] ranges);
+        public virtual IEnumerable<int> GetAllowedCodePoints();
+    }
+    public abstract class UrlEncoder : TextEncoder {
+        protected UrlEncoder();
+        public static UrlEncoder Default { get; }
+        public static UrlEncoder Create(TextEncoderSettings settings);
+        public static UrlEncoder Create(params UnicodeRange[] allowedRanges);
+    }
+}
```