Decodifica HTML senza System.Web

Question

Sto lavorando su una funzione con valori di tabella CLR per SQL Server 2008 R2. Ho bisogno di HTMLDecode una stringa in un punto, ma questo è problematico b/c che si basa su System.Web, che non è un assembly di supporto per SQL Server.

Qualcuno può pensare a un modo migliore per eseguire la decodifica HTML?

FYI SQL Server 2008 CLR supporta solo fino a .NET 3.5, quindi system.net.webutility non funzionerà.

Answer 1

Inoltre è possibile utilizzare riflettore per afferrare il codice da WebUtility direttamente (per favore non mi colpa per lo stile di codifica, la sua roba riflessa):

public class WebUtility { 
                                                                                                                                            private static class HtmlEntities { 
    private static string[] _entitiesList = new string[] 
     { 
      "\"-quot", 
      "&-amp", 
      "'-apos", 
      "<-lt", 
      ">-gt", 
      "\u00a0-nbsp", 
      "¡-iexcl", 
      "¢-cent", 
      "£-pound", 
      "¤-curren", 
      "¥-yen", 
      "¦-brvbar", 
      "§-sect", 
      "¨-uml", 
      "©-copy", 
      "ª-ordf", 
      "«-laquo", 
      "¬-not", 
      "­-shy", 
      "®-reg", 
      "¯-macr", 
      "°-deg", 
      "±-plusmn", 
      "²-sup2", 
      "³-sup3", 
      "´-acute", 
      "µ-micro", 
      "¶-para", 
      "·-middot", 
      "¸-cedil", 
      "¹-sup1", 
      "º-ordm", 
      "»-raquo", 
      "¼-frac14", 
      "½-frac12", 
      "¾-frac34", 
      "¿-iquest", 
      "À-Agrave", 
      "Á-Aacute", 
      "Â-Acirc", 
      "Ã-Atilde", 
      "Ä-Auml", 
      "Å-Aring", 
      "Æ-AElig", 
      "Ç-Ccedil", 
      "È-Egrave", 
      "É-Eacute", 
      "Ê-Ecirc", 
      "Ë-Euml", 
      "Ì-Igrave", 
      "Í-Iacute", 
      "Î-Icirc", 
      "Ï-Iuml", 
      "Ð-ETH", 
      "Ñ-Ntilde", 
      "Ò-Ograve", 
      "Ó-Oacute", 
      "Ô-Ocirc", 
      "Õ-Otilde", 
      "Ö-Ouml", 
      "×-times", 
      "Ø-Oslash", 
      "Ù-Ugrave", 
      "Ú-Uacute", 
      "Û-Ucirc", 
      "Ü-Uuml", 
      "Ý-Yacute", 
      "Þ-THORN", 
      "ß-szlig", 
      "à-agrave", 
      "á-aacute", 
      "â-acirc", 
      "ã-atilde", 
      "ä-auml", 
      "å-aring", 
      "æ-aelig", 
      "ç-ccedil", 
      "è-egrave", 
      "é-eacute", 
      "ê-ecirc", 
      "ë-euml", 
      "ì-igrave", 
      "í-iacute", 
      "î-icirc", 
      "ï-iuml", 
      "ð-eth", 
      "ñ-ntilde", 
      "ò-ograve", 
      "ó-oacute", 
      "ô-ocirc", 
      "õ-otilde", 
      "ö-ouml", 
      "÷-divide", 
      "ø-oslash", 
      "ù-ugrave", 
      "ú-uacute", 
      "û-ucirc", 
      "ü-uuml", 
      "ý-yacute", 
      "þ-thorn", 
      "ÿ-yuml", 
      "Œ-OElig", 
      "œ-oelig", 
      "Š-Scaron", 
      "š-scaron", 
      "Ÿ-Yuml", 
      "ƒ-fnof", 
      "ˆ-circ", 
      "˜-tilde", 
      "Α-Alpha", 
      "Β-Beta", 
      "Γ-Gamma", 
      "Δ-Delta", 
      "Ε-Epsilon", 
      "Ζ-Zeta", 
      "Η-Eta", 
      "Θ-Theta", 
      "Ι-Iota", 
      "Κ-Kappa", 
      "Λ-Lambda", 
      "Μ-Mu", 
      "Ν-Nu", 
      "Ξ-Xi", 
      "Ο-Omicron", 
      "Π-Pi", 
      "Ρ-Rho", 
      "Σ-Sigma", 
      "Τ-Tau", 
      "Υ-Upsilon", 
      "Φ-Phi", 
      "Χ-Chi", 
      "Ψ-Psi", 
      "Ω-Omega", 
      "α-alpha", 
      "β-beta", 
      "γ-gamma", 
      "δ-delta", 
      "ε-epsilon", 
      "ζ-zeta", 
      "η-eta", 
      "θ-theta", 
      "ι-iota", 
      "κ-kappa", 
      "λ-lambda", 
      "μ-mu", 
      "ν-nu", 
      "ξ-xi", 
      "ο-omicron", 
      "π-pi", 
      "ρ-rho", 
      "ς-sigmaf", 
      "σ-sigma", 
      "τ-tau", 
      "υ-upsilon", 
      "φ-phi", 
      "χ-chi", 
      "ψ-psi", 
      "ω-omega", 
      "ϑ-thetasym", 
      "ϒ-upsih", 
      "ϖ-piv", 
      "\u2002-ensp", 
      "\u2003-emsp", 
      "\u2009-thinsp", 
      "‌-zwnj", 
      "‍-zwj", 
      "‎-lrm", 
      "‏-rlm", 
      "–-ndash", 
      "—-mdash", 
      "‘-lsquo", 
      "’-rsquo", 
      "‚-sbquo", 
      "“-ldquo", 
      "”-rdquo", 
      "„-bdquo", 
      "†-dagger", 
      "‡-Dagger", 
      "•-bull", 
      "…-hellip", 
      "‰-permil", 
      "′-prime", 
      "″-Prime", 
      "‹-lsaquo", 
      "›-rsaquo", 
      "‾-oline", 
      "⁄-frasl", 
      "€-euro", 
      "ℑ-image", 
      "℘-weierp", 
      "ℜ-real", 
      "™-trade", 
      "ℵ-alefsym", 
      "←-larr", 
      "↑-uarr", 
      "→-rarr", 
      "↓-darr", 
      "↔-harr", 
      "↵-crarr", 
      "⇐-lArr", 
      "⇑-uArr", 
      "⇒-rArr", 
      "⇓-dArr", 
      "⇔-hArr", 
      "∀-forall", 
      "∂-part", 
      "∃-exist", 
      "∅-empty", 
      "∇-nabla", 
      "∈-isin", 
      "∉-notin", 
      "∋-ni", 
      "∏-prod", 
      "∑-sum", 
      "−-minus", 
      "∗-lowast", 
      "√-radic", 
      "∝-prop", 
      "∞-infin", 
      "∠-ang", 
      "∧-and", 
      "∨-or", 
      "∩-cap", 
      "∪-cup", 
      "∫-int", 
      "∴-there4", 
      "∼-sim", 
      "≅-cong", 
      "≈-asymp", 
      "≠-ne", 
      "≡-equiv", 
      "≤-le", 
      "≥-ge", 
      "⊂-sub", 
      "⊃-sup", 
      "⊄-nsub", 
      "⊆-sube", 
      "⊇-supe", 
      "⊕-oplus", 
      "⊗-otimes", 
      "⊥-perp", 
      "⋅-sdot", 
      "⌈-lceil", 
      "⌉-rceil", 
      "⌊-lfloor", 
      "⌋-rfloor", 
      "〈-lang", 
      "〉-rang", 
      "◊-loz", 
      "♠-spades", 
      "♣-clubs", 
      "♥-hearts", 
      "♦-diams" 
     }; 
    private static Dictionary<string, char> _lookupTable = WebUtility.HtmlEntities.GenerateLookupTable(); 
    private static Dictionary<string, char> GenerateLookupTable() { 
    Dictionary<string, char> dictionary = new Dictionary<string, char>(StringComparer.Ordinal); 
    string[] entitiesList = WebUtility.HtmlEntities._entitiesList; 
    for (int i = 0; i < entitiesList.Length; i++) { 
     string text = entitiesList[i]; 
     dictionary.Add(text.Substring(2), text[0]); 
    } 
    return dictionary; 
    } 
    public static char Lookup(string entity) { 
    char result; 
    WebUtility.HtmlEntities._lookupTable.TryGetValue(entity, out result); 
    return result; 
    } 
} 
    private enum UnicodeDecodingConformance { 
    Auto, 
    Strict, 
    Compat, 
    Loose 
    } 

    private static char[] _htmlEntityEndingChars = new char[] { ';', '&' }; 
    private static readonly UnicodeDecodingConformance _htmlDecodeConformance = UnicodeDecodingConformance.Auto; 

    public static string HtmlDecode(string value) { 
    if (string.IsNullOrEmpty(value)) { 
     return value; 
    } 
    if (!WebUtility.StringRequiresHtmlDecoding(value)) { 
     return value; 
    } 
    StringWriter stringWriter = new StringWriter(CultureInfo.InvariantCulture); 
    WebUtility.HtmlDecode(value, stringWriter); 
    return stringWriter.ToString(); 
    } 

    private static bool StringRequiresHtmlDecoding(string s) { 
    if (WebUtility._htmlDecodeConformance == UnicodeDecodingConformance.Compat) { 
     return s.IndexOf('&') >= 0; 
    } 
    for (int i = 0; i < s.Length; i++) { 
     char c = s[i]; 
     if (c == '&' || char.IsSurrogate(c)) { 
     return true; 
     } 
    } 
    return false; 
    } 

    private static void ConvertSmpToUtf16(uint smpChar, out char leadingSurrogate, out char trailingSurrogate) { 
    int num = (int)(smpChar - 65536u); 
    leadingSurrogate = (char)(num/1024 + 55296); 
    trailingSurrogate = (char)(num % 1024 + 56320); 
    } 

    public static void HtmlDecode(string value, TextWriter output) { 
    if (value == null) { 
     return; 
    } 
    if (output == null) { 
     throw new ArgumentNullException("output"); 
    } 
    if (!WebUtility.StringRequiresHtmlDecoding(value)) { 
     output.Write(value); 
     return; 
    } 
    int length = value.Length; 
    int i = 0; 
    while (i < length) { 
     char c = value[i]; 
     if (c != '&') { 
     goto IL_1B6; 
     } 
     int num = value.IndexOfAny(WebUtility._htmlEntityEndingChars, i + 1); 
     if (num <= 0 || value[num] != ';') { 
     goto IL_1B6; 
     } 
     string text = value.Substring(i + 1, num - i - 1); 
     if (text.Length > 1 && text[0] == '#') { 
     uint num2; 
     bool flag; 
     if (text[1] == 'x' || text[1] == 'X') { 
      flag = uint.TryParse(text.Substring(2), NumberStyles.AllowHexSpecifier, NumberFormatInfo.InvariantInfo, out num2); 
     } else { 
      flag = uint.TryParse(text.Substring(1), NumberStyles.Integer, NumberFormatInfo.InvariantInfo, out num2); 
     } 
     if (flag) { 
      switch (WebUtility._htmlDecodeConformance) { 
      case UnicodeDecodingConformance.Strict: 
       flag = (num2 < 55296u || (57343u < num2 && num2 <= 1114111u)); 
       break; 
      case UnicodeDecodingConformance.Compat: 
       flag = (0u < num2 && num2 <= 65535u); 
       break; 
      case UnicodeDecodingConformance.Loose: 
       flag = (num2 <= 1114111u); 
       break; 
      default: 
       flag = false; 
       break; 
      } 
     } 
     if (!flag) { 
      goto IL_1B6; 
     } 
     if (num2 <= 65535u) { 
      output.Write((char)num2); 
     } else { 
      char value2; 
      char value3; 
      WebUtility.ConvertSmpToUtf16(num2, out value2, out value3); 
      output.Write(value2); 
      output.Write(value3); 
     } 
     i = num; 
     } else { 
     i = num; 
     char c2 = WebUtility.HtmlEntities.Lookup(text); 
     if (c2 != '\0') { 
      c = c2; 
      goto IL_1B6; 
     } 
     output.Write('&'); 
     output.Write(text); 
     output.Write(';'); 
     } 
    IL_1BD: 
     i++; 
     continue; 
    IL_1B6: 
     output.Write(c); 
     goto IL_1BD; 
    } 
    } 
}