{-----------------------------------------------------------------------------
The contents of this file are subject to the Mozilla Public License
Version 1.1 (the "License"); you may not use this file except in compliance
with the License. You may obtain a copy of the License at
http://www.mozilla.org/MPL/MPL-1.1.html

Software distributed under the License is distributed on an "AS IS" basis,
WITHOUT WARRANTY OF ANY KIND, either expressed or implied. See the License for
the specific language governing rights and limitations under the License.

The Original Code is: JvStrToHtml.PAS, released on 2001-02-28.

The Initial Developer of the Original Code is Sébastien Buysse [sbuysse att buypin dott com]
Portions created by Sébastien Buysse are Copyright (C) 2001 Sébastien Buysse.
All Rights Reserved.

Contributor(s): Michael Beck [mbeck att bigfoot dott com].
                Andreas Hausladen [Andreas dott Hausladen att gmx dott de]

You may retrieve the latest version of this file at the Project JEDI's JVCL home page,
located at http://jvcl.delphi-jedi.org

Known Issues:
-----------------------------------------------------------------------------}
// $Id$

unit JvStrToHtml;

{$mode objfpc}{$H+}

interface

uses
  SysUtils, Classes;

type
  TJvStrToHtml = class(TComponent)  // TJvComponent)
  private
    FHtml: string;
    FValue: string;
    procedure SetHtml(const Value: string);
    procedure SetValue(const Value: string);
  public
    constructor Create(AOwner: TComponent); override;
    function TextToHtml(const Text: string): string;
    function HtmlToText(const Text: string): string;
  published
    property Text: string read FValue write SetValue;
    property Html: string read FHtml write SetHtml;
  end;

function StringToHtml(const Value: string): string;
function HtmlToString(const Value: string): string;
//function CharToHtml(Ch: Char): string;


implementation

uses
  LCLVersion, LazUtf8;

type
  TJvHtmlCodeRec = record
    Ch: Cardinal;
    Html: string;
  end;

const
  { References:
      http://www.w3.org/TR/REC-html40/charset.html#h-5.3
      http://www.w3.org/TR/REC-html40/sgml/entities.html#h-24.2.1
      http://www.w3.org/TR/REC-html40/sgml/entities.html#h-24.4.1
  }

  Conversions: array [0..240] of TJvHtmlCodeRec = (
    (Ch:   34; Html: '"'),
    (Ch:   38; Html: '&'),
    (Ch:   39; Html: '''),
    (Ch:   60; Html: '<'),
    (Ch:   62; Html: '>'),
    (Ch:  160; Html: ' '),
    (Ch:  161; Html: '¡'),
    (Ch:  162; Html: '¢'),
    (Ch:  163; Html: '£'),
    (Ch:  164; Html: '¤'),
    (Ch:  165; Html: '¥'),
    (Ch:  166; Html: '¦'),
    (Ch:  167; Html: '§'),
    (Ch:  168; Html: '¨'),
    (Ch:  169; Html: '©'),
    (Ch:  170; Html: 'ª'),
    (Ch:  171; Html: '«'),
    (Ch:  172; Html: '¬'),
    (Ch:  173; Html: '­'),
    (Ch:  174; Html: '®'),
    (Ch:  175; Html: '¯'),
    (Ch:  176; Html: '°'),
    (Ch:  177; Html: '±'),
    (Ch:  178; Html: '²'),
    (Ch:  179; Html: '³'),
    (Ch:  180; Html: '´'),
    (Ch:  181; Html: 'µ'),
    (Ch:  182; Html: '¶'),
    (Ch:  183; Html: '·'),
    (Ch:  184; Html: '¸'),
    (Ch:  185; Html: '¹'),
    (Ch:  186; Html: 'º'),
    (Ch:  187; Html: '»'),
    (Ch:  188; Html: '¼'),
    (Ch:  189; Html: '½'),
    (Ch:  190; Html: '¾'),
    (Ch:  191; Html: '¿'),
    (Ch:  192; Html: 'À'),
    (Ch:  193; Html: 'Á'),
    (Ch:  194; Html: 'Â'),
    (Ch:  195; Html: 'Ã'),
    (Ch:  196; Html: 'Ä'),
    (Ch:  197; Html: 'Å'),
    (Ch:  198; Html: 'Æ'),
    (Ch:  199; Html: 'Ç'),
    (Ch:  200; Html: 'È'),
    (Ch:  201; Html: 'É'),
    (Ch:  202; Html: 'Ê'),
    (Ch:  203; Html: 'Ë'),
    (Ch:  204; Html: 'Ì'),
    (Ch:  205; Html: 'Í'),
    (Ch:  206; Html: 'Î'),
    (Ch:  207; Html: 'Ï'),
    (Ch:  208; Html: 'Ð'),
    (Ch:  209; Html: 'Ñ'),
    (Ch:  210; Html: 'Ò'),
    (Ch:  211; Html: 'Ó'),
    (Ch:  212; Html: 'Ô'),
    (Ch:  213; Html: 'Õ'),
    (Ch:  214; Html: 'Ö'),
    (Ch:  215; Html: '×'),
    (Ch:  216; Html: 'Ø'),
    (Ch:  217; Html: 'Ù'),
    (Ch:  218; Html: 'Ú'),
    (Ch:  219; Html: 'Û'),
    (Ch:  220; Html: 'Ü'),
    (Ch:  221; Html: 'Ý'),
    (Ch:  222; Html: 'Þ'),
    (Ch:  223; Html: 'ß'),
    (Ch:  224; Html: 'à'),
    (Ch:  225; Html: 'á'),
    (Ch:  226; Html: 'â'),
    (Ch:  227; Html: 'ã'),
    (Ch:  228; Html: 'ä'),
    (Ch:  229; Html: 'å'),
    (Ch:  230; Html: 'æ'),
    (Ch:  231; Html: 'ç'),
    (Ch:  232; Html: 'è'),
    (Ch:  233; Html: 'é'),
    (Ch:  234; Html: 'ê'),
    (Ch:  235; Html: 'ë'),
    (Ch:  236; Html: 'ì'),
    (Ch:  237; Html: 'í'),
    (Ch:  238; Html: 'î'),
    (Ch:  239; Html: 'ï'),
    (Ch:  240; Html: 'ð'),
    (Ch:  241; Html: 'ñ'),
    (Ch:  242; Html: 'ò'),
    (Ch:  243; Html: 'ó'),
    (Ch:  244; Html: 'ô'),
    (Ch:  245; Html: 'õ'),
    (Ch:  246; Html: 'ö'),
    (Ch:  247; Html: '÷'),
    (Ch:  248; Html: 'ø'),
    (Ch:  249; Html: 'ù'),
    (Ch:  250; Html: 'ú'),
    (Ch:  251; Html: 'û'),
    (Ch:  252; Html: 'ü'),
    (Ch:  253; Html: 'ý'),
    (Ch:  254; Html: 'þ'),
    (Ch:  255; Html: 'ÿ'),
    (Ch:  338; Html: 'Œ'),
    (Ch:  339; Html: 'œ'),
    (Ch:  352; Html: 'Š'),
    (Ch:  353; Html: 'š'),
    (Ch:  376; Html: 'Ÿ'),
    (Ch:  402; Html: 'ƒ'),
    (Ch:  710; Html: 'ˆ'),
    (Ch:  732; Html: '˜'),
    (Ch:  913; Html: 'Α'),
    (Ch:  914; Html: 'Β'),
    (Ch:  915; Html: 'Γ'),
    (Ch:  916; Html: 'Δ'),
    (Ch:  917; Html: 'Ε'),
    (Ch:  918; Html: 'Ζ'),
    (Ch:  919; Html: 'Η'),
    (Ch:  920; Html: 'Θ'),
    (Ch:  921; Html: 'Ι'),
    (Ch:  922; Html: 'Κ'),
    (Ch:  923; Html: 'Λ'),
    (Ch:  924; Html: 'Μ'),
    (Ch:  925; Html: 'Ν'),
    (Ch:  926; Html: 'Ξ'),
    (Ch:  927; Html: 'Ο'),
    (Ch:  928; Html: 'Π'),
    (Ch:  929; Html: 'Ρ'),
    (Ch:  931; Html: 'Σ'),
    (Ch:  932; Html: 'Τ'),
    (Ch:  933; Html: 'Υ'),
    (Ch:  934; Html: 'Φ'),
    (Ch:  935; Html: 'Χ'),
    (Ch:  936; Html: 'Ψ'),
    (Ch:  937; Html: 'Ω'),
    (Ch:  945; Html: 'α'),
    (Ch:  946; Html: 'β'),
    (Ch:  947; Html: 'γ'),
    (Ch:  948; Html: 'δ'),
    (Ch:  949; Html: 'ε'),
    (Ch:  950; Html: 'ζ'),
    (Ch:  951; Html: 'η'),
    (Ch:  952; Html: 'θ'),
    (Ch:  953; Html: 'ι'),
    (Ch:  954; Html: 'κ'),
    (Ch:  955; Html: 'λ'),
    (Ch:  956; Html: 'μ'),
    (Ch:  957; Html: 'ν'),
    (Ch:  958; Html: 'ξ'),
    (Ch:  959; Html: 'ο'),
    (Ch:  960; Html: 'π'),
    (Ch:  961; Html: 'ρ'),
    (Ch:  962; Html: 'ς'),
    (Ch:  963; Html: 'σ'),
    (Ch:  964; Html: 'τ'),
    (Ch:  965; Html: 'υ'),
    (Ch:  966; Html: 'φ'),
    (Ch:  967; Html: 'χ'),
    (Ch:  968; Html: 'ψ'),
    (Ch:  969; Html: 'ω'),
    (Ch:  977; Html: 'ϑ'),
    (Ch:  978; Html: 'ϒ'),
    (Ch:  982; Html: 'ϖ'),
    (Ch: 8194; Html: ' '),
    (Ch: 8195; Html: ' '),
    (Ch: 8201; Html: ' '),
    (Ch: 8204; Html: '‌'),
    (Ch: 8205; Html: '‍'),
    (Ch: 8206; Html: '‎'),
    (Ch: 8207; Html: '‏'),
    (Ch: 8211; Html: '–'),
    (Ch: 8212; Html: '—'),
    (Ch: 8216; Html: '‘'),
    (Ch: 8217; Html: '’'),
    (Ch: 8218; Html: '‚'),
    (Ch: 8220; Html: '“'),
    (Ch: 8221; Html: '”'),
    (Ch: 8222; Html: '„'),
    (Ch: 8224; Html: '†'),
    (Ch: 8225; Html: '‡'),
    (Ch: 8226; Html: '•'),
    (Ch: 8230; Html: '…'),
    (Ch: 8240; Html: '‰'),
    (Ch: 8242; Html: '′'),
    (Ch: 8243; Html: '″'),
    (Ch: 8249; Html: '‹'),
    (Ch: 8250; Html: '›'),
    (Ch: 8254; Html: '‾'),
    (Ch: 8364; Html: '€'),
    (Ch: 8482; Html: '™'),
    (Ch: 8592; Html: '←'),
    (Ch: 8593; Html: '↑'),
    (Ch: 8594; Html: '→'),
    (Ch: 8595; Html: '↓'),
    (Ch: 8596; Html: '↔'),
    (Ch: 8629; Html: '↵'),
    (Ch: 8704; Html: '∀'),
    (Ch: 8706; Html: '∂'),
    (Ch: 8707; Html: '∃'),
    (Ch: 8709; Html: '∅'),
    (Ch: 8711; Html: '∇'),
    (Ch: 8712; Html: '∈'),
    (Ch: 8713; Html: '∉'),
    (Ch: 8715; Html: '∋'),
    (Ch: 8719; Html: '∏'),
    (Ch: 8721; Html: '∑'),
    (Ch: 8722; Html: '−'),
    (Ch: 8727; Html: '∗'),
    (Ch: 8730; Html: '√'),
    (Ch: 8733; Html: '∝'),
    (Ch: 8734; Html: '∞'),
    (Ch: 8736; Html: '∠'),
    (Ch: 8743; Html: '∧'),
    (Ch: 8744; Html: '∨'),
    (Ch: 8745; Html: '∩'),
    (Ch: 8746; Html: '∪'),
    (Ch: 8747; Html: '∫'),
    (Ch: 8756; Html: '∴'),
    (Ch: 8764; Html: '∼'),
    (Ch: 8773; Html: '≅'),
    (Ch: 8776; Html: '≈'),
    (Ch: 8800; Html: '≠'),
    (Ch: 8801; Html: '≡'),
    (Ch: 8804; Html: '≤'),
    (Ch: 8805; Html: '≥'),
    (Ch: 8834; Html: '⊂'),
    (Ch: 8835; Html: '⊃'),
    (Ch: 8836; Html: '⊄'),
    (Ch: 8838; Html: '⊆'),
    (Ch: 8839; Html: '⊇'),
    (Ch: 8853; Html: '⊕'),
    (Ch: 8855; Html: '⊗'),
    (Ch: 8869; Html: '⊥'),
    (Ch: 8901; Html: '⋅'),
    (Ch: 8968; Html: '⌈'),
    (Ch: 8969; Html: '⌉'),
    (Ch: 8970; Html: '⌊'),
    (Ch: 8971; Html: '⌋'),
    (Ch: 9674; Html: '◊'),
    (Ch: 9824; Html: '♠'),
    (Ch: 9827; Html: '♣'),
    (Ch: 9829; Html: '♥'),
    (Ch: 9830; Html: '♦')
  );

var
  ConversionsHash: array of Word;


  { TJvStrToHtml }

constructor TJvStrToHtml.Create(AOwner: TComponent);
begin
  inherited Create(AOwner);
  FValue := '';
  FHtml := '';
end;

function TJvStrToHtml.HtmlToText(const Text: string): string;
begin
  Result := HtmlToString(Text);
end;

procedure TJvStrToHtml.SetHtml(const Value: string);
begin
  FValue := HtmlToText(Value);
end;

procedure TJvStrToHtml.SetValue(const Value: string);
begin
  FHtml := TextToHtml(Value);
end;

function TJvStrToHtml.TextToHtml(const Text: string): string;
begin
  Result := StringToHtml(Text);
end;

function GetHtmlHash(const S: string): Word;
var
  I: Integer;
begin
  Result := Length(S);
  for I := 1 to Length(S) do
    Result := Word(Result + Ord(S[I]) shl (I mod 4));
end;

procedure InitConversionsHash;
var
  I: Integer;
begin
  SetLength(ConversionsHash, Length(Conversions));
  for I := 0 to High(ConversionsHash) do
    ConversionsHash[I] := GetHtmlHash(Conversions[I].Html);
end;

function StringToHtml(const Value: String): String;
var
  ResultLen: Integer;
  CurrPos: Integer;
  P, PEnd: PChar;

  procedure Append(s: String);
  var
    n: Integer;
  begin
    n := Length(s);
    if CurrPos + n > ResultLen then begin
      ResultLen := ResultLen + 100;
      SetLength(Result, ResultLen);
    end;
    Move(s[1], Result[CurrPos], n);
    inc(CurrPos, n);
  end;

var
  J, n: Integer;
  ch: Cardinal;
  found: Boolean;
begin
  if Value = '' then begin
    Result := '';
    exit;
  end;

  ResultLen := Length(Value);
  SetLength(Result, ResultLen);

  P := @Value[1];
  PEnd := @Value[ResultLen];
  CurrPos := 1;
  while P <= PEnd do begin
    n := 1;
    if P^ in ['a'..'z', 'A'..'Z', '0'..'9', '_', ' '] then
      Append(P^)
    else begin
      {$IF LCL_FullVersion >= 2000000}
      ch := UTF8CodePointToUniCode(P, n);
      {$ELSE}
      ch := UTF8CharacterToUniCode(P, n);
      {$IFEND}
      found := false;
      for J := Low(Conversions) to High(Conversions) do
        if ch = Conversions[J].Ch then begin
          Append(Conversions[J].Html);
          found := true;
          break;
        end;
      if not found then
        Append(Format('&#%d;', [ch]));
    end;
    inc(P, n);
  end;
  SetLength(Result, CurrPos-1);
end;

function HtmlToString(const Value: String): String;
var
  ResultLen: Integer;
  P, PEnd: PChar;
  CurrPos: Integer;

  procedure Append(s: String);
  var
    n: Integer;
  begin
    n := Length(s);
    Move(s[1], Result[CurrPos], n);
    inc(CurrPos, n);
  end;

var
  html: String;
  found: Boolean;
  J: Integer;
begin
  if Value = '' then begin
    Result := '';
    exit;
  end;

  ResultLen := Length(Value);
  SetLength(Result, ResultLen);

  P := @Value[1];
  PEnd := @Value[ResultLen];
  CurrPos := 1;

  while P <= PEnd do begin
    if P^ = '&' then begin
      html := '&';
      while P < PEnd do begin
        inc(P);
        html := html + P^;
        if P^ = ';' then break;
      end;
      found := false;
      for J := Low(Conversions) to High(Conversions) do
        if html = Conversions[J].Html then begin
          Append(UnicodeToUTF8(Conversions[j].Ch));
          found := true;
          break;
        end;
      if not found then begin
        Delete(html, Length(html), 1);
        Delete(html, 1, 1);
        if html[1] = '#' then Delete(html, 1, 1);
        if html[1] = 'x' then html[1] := '$';
        Append(UnicodeToUTF8(StrToInt(html)));
      end;
    end else
      Append(P^);
    inc(P);
  end;
  SetLength(Result, CurrPos-1);
end;

end.