I'm using Delphi 2009 and want to decode an HTML encoded string, for example:
' -> '
But cannot find any built in function for doing this.
Thanks in advance
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What HTML parsing library are you using? Doesn't it come with such a function? – Rob Kennedy Nov 01 '09 at 13:53
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Hi Rob, I'm using Winninet for getting the data from the website. – tekBlues Nov 01 '09 at 14:42
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That's not what I asked. Once you download the resource from the Web server, what library are you using to parse it? What do you use the turn the sequence of characters into something meaningful? (And if you're not using anything, why aren't you?) – Rob Kennedy Nov 01 '09 at 15:43
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It's a JSON file, and I'm using the Superobject JSON object for Delphi. – tekBlues Nov 01 '09 at 20:49
4 Answers
18
Look at the HTTPApp unit. HTTPDecode and HTMLDecode (as well as the Encode functions). You should find this in your Source/Win32/Internet folder.
9
The HttpApp.HttpDecode function doesn't decode http entities (https://www.w3.org/TR/html4/sgml/entities.html#sym)
For example: ∴ → ∴
function HtmlDecode(s: UnicodeString): UnicodeString;
{
Public domain: No attribution required
Known issue, it doesn't handle entities with characters code points above $FFFF (65536)
e.g.: &;
That's because UTF-16 requires 2 characters to encode one character.
}
function UCS4CharToString(uch: UCS4Char): UnicodeString;
var
s: UCS4String;
begin
SetLength(s, 2);
s[0] := uch;
s[1] := 0; //null terminator
Result := UCS4StringToUnicodeString(s);
end;
function GetCharRef(sValue: UnicodeString; StartIndex: Integer; out CharRef: string): UnicodeString;
var
i: Integer;
len: Integer;
nChar: UCS4Char;
begin
{
Character references come in either decimal or hex forms:
♦ //decimal
♦ //hexidecimal
As per the definition:
CharRef ::= '&#' [0-9]+ ';'
|
'&#x' [0-9a-fA-F]+ ';'
}
Result := '';
CharRef := '';
len := Length(sValue) - StartIndex + 1;
if len < 4 then
Exit;
i := StartIndex;
if sValue[i] <> '&' then Exit;
Inc(i);
if sValue[i] <> '#' then Exit;
Inc(i);
if sValue[i] = 'x' then
begin
{
Hex character reference
CharRef ::= '&#x' [0-9a-fA-F]+ ';'
E.g. ♦
}
Inc(i); //skip the x
while CharInSet(sValue[i], ['0'..'9', 'a'..'f', 'A'..'F']) do
begin
Inc(i);
if i > Length(sValue) then
Exit;
end;
if sValue[i] <> ';' then
Exit;
charRef := Copy(sValue, StartIndex, (i-StartIndex)+1);
nChar := StrToInt('$'+Copy(charRef, 4, Length(charRef)-4));
end
else
begin
{
Decimal character reference
CharRef ::= '&#' [0-9]+ ';'
E.g. ♦
}
while CharInSet(sValue[i], ['0'..'9']) do
begin
Inc(i);
if i > Length(sValue) then
Exit;
end;
if sValue[i] <> ';' then
Exit;
charRef := Copy(sValue, StartIndex, (i-StartIndex)+1);
nChar := StrToInt(Copy(charRef, 3, Length(charRef)-3));
end;
Result := UCS4CharToString(nChar);
end;
function GetEntityRef(sValue: string; StartIndex: Integer; out CharRef: string): UnicodeString;
function IsNameStartChar(ch: WideChar): Boolean;
begin
{
NameStartChar ::= ":" | [A-Z] | "_" | [a-z] | [#xC0-#xD6] | [#xD8-#xF6] | [#xF8-#x2FF] | [#x370-#x37D] | [#x37F-#x1FFF] | [#x200C-#x200D] | [#x2070-#x218F] | [#x2C00-#x2FEF] | [#x3001-#xD7FF] | [#xF900-#xFDCF] | [#xFDF0-#xFFFD] | [#x10000-#xEFFFF]
}
Result := False;
case ch of
':', 'A'..'Z', '_', 'a'..'z', #$C0..#$D6, #$D8..#$F6, #$F8..#$FF: Result := True;
#$100..#$2FF, #$370..#$37D, #$37F..#$FFF: Result := True;
#$1000..#$1FFF, #$200C..#$200D, #$2070..#$218F, #$2C00..#$2FEF, #$3001..#$D7FF, #$F900..#$FDCF, #$FDF0..#$FFFD: Result := True;
else
//We assume strings are UTF-16. But by assuming one 16-bit word is the same as one character is just wrong.
//UTF-16, like UTF-8 can be multi-byte.
//But it's just so haaaard to support.
//The correct action is to convert the string to UCS4, where one code-point is always one character.
case Integer(ch) of
$10000..$EFFFF: Result := True;
end;
end;
end;
function IsNameChar(ch: WideChar): Boolean;
begin
if IsNameStartChar(ch) then
begin
Result := True;
Exit;
end;
case ch of
'-', '.', '0'..'9', #$B7, #$0300..#$036F, #$203F..#$2040: Result := True;
else
Result := False;
end;
end;
type
THtmlEntity = record
entity: string;
ch: UCS4Char;
end;
const
//https://www.w3.org/TR/html4/sgml/entities.html#sym
//html entities are case sensitive (e.g. "larr" is different from "lArr")
HtmlEntities: array[0..252] of THtmlEntity = (
(entity: 'apos'; ch: 39; ), // apostrophe (originally only existed in xml, and not in HTML. Was added to HTML5
(entity: 'quot'; ch: 34; ), // quotation mark = APL quote, U+0022
(entity: 'amp'; ch: 38; ), // ampersand, U+0026
(entity: 'lt'; ch: 60; ), // less-than sign, U+003C
(entity: 'gt'; ch: 62; ), // greater-than sign, U+003E
(entity: 'OElig'; ch: 338; ), // latin capital ligature OE, U+0152
(entity: 'oelig'; ch: 339; ), // latin small ligature oe, U+0153
(entity: 'Scaron'; ch: 352; ), // latin capital letter S with caron, U+0160
(entity: 'scaron'; ch: 353; ), // latin small letter s with caron, U+0161
(entity: 'Yuml'; ch: 376; ), // latin capital letter Y with diaeresis, U+0178
(entity: 'circ'; ch: 710; ), // modifier letter circumflex accent, U+02C6
(entity: 'tilde'; ch: 732; ), // small tilde, U+02DC
(entity: 'nbsp'; ch: 160; ), // no-break space = non-breaking space, U+00A0
(entity: 'iexcl'; ch: 161; ), // inverted exclamation mark, U+00A1
(entity: 'cent'; ch: 162; ), // cent sign, U+00A2
(entity: 'pound'; ch: 163; ), // pound sign, U+00A3
(entity: 'curren'; ch: 164; ), // currency sign, U+00A4
(entity: 'yen'; ch: 165; ), // yen sign = yuan sign, U+00A5
(entity: 'brvbar'; ch: 166; ), // broken bar = broken vertical bar, U+00A6
(entity: 'sect'; ch: 167; ), // section sign, U+00A7
(entity: 'uml'; ch: 168; ), // diaeresis = spacing diaeresis, U+00A8
(entity: 'copy'; ch: 169; ), // copyright sign, U+00A9
(entity: 'ordf'; ch: 170; ), // feminine ordinal indicator, U+00AA
(entity: 'laquo'; ch: 171; ), // left-pointing double angle quotation mark = left pointing guillemet, U+00AB
(entity: 'not'; ch: 172; ), // not sign, U+00AC
(entity: 'shy'; ch: 173; ), // soft hyphen = discretionary hyphen, U+00AD
(entity: 'reg'; ch: 174; ), // registered sign = registered trade mark sign, U+00AE
(entity: 'macr'; ch: 175; ), // macron = spacing macron = overline = APL overbar, U+00AF
(entity: 'deg'; ch: 176; ), // degree sign, U+00B0
(entity: 'plusmn'; ch: 177; ), // plus-minus sign = plus-or-minus sign, U+00B1
(entity: 'sup2'; ch: 178; ), // superscript two = superscript digit two = squared, U+00B2
(entity: 'sup3'; ch: 179; ), // superscript three = superscript digit three = cubed, U+00B3
(entity: 'acute'; ch: 180; ), // acute accent = spacing acute, U+00B4
(entity: 'micro'; ch: 181; ), // micro sign, U+00B5
(entity: 'para'; ch: 182; ), // pilcrow sign = paragraph sign, U+00B6
(entity: 'middot'; ch: 183; ), // middle dot = Georgian comma = Greek middle dot, U+00B7
(entity: 'cedil'; ch: 184; ), // cedilla = spacing cedilla, U+00B8
(entity: 'sup1'; ch: 185; ), // superscript one = superscript digit one, U+00B9
(entity: 'ordm'; ch: 186; ), // masculine ordinal indicator, U+00BA
(entity: 'raquo'; ch: 187; ), // right-pointing double angle quotation mark = right pointing guillemet, U+00BB
(entity: 'frac14'; ch: 188; ), // vulgar fraction one quarter = fraction one quarter, U+00BC
(entity: 'frac12'; ch: 189; ), // vulgar fraction one half = fraction one half, U+00BD
(entity: 'frac34'; ch: 190; ), // vulgar fraction three quarters = fraction three quarters, U+00BE
(entity: 'iquest'; ch: 191; ), // inverted question mark = turned question mark, U+00BF
(entity: 'Agrave'; ch: 192; ), // latin capital letter A with grave = latin capital letter A grave, U+00C0
(entity: 'Aacute'; ch: 193; ), // latin capital letter A with acute, U+00C1
(entity: 'Acirc'; ch: 194; ), // latin capital letter A with circumflex, U+00C2
(entity: 'Atilde'; ch: 195; ), // latin capital letter A with tilde, U+00C3
(entity: 'Auml'; ch: 196; ), // latin capital letter A with diaeresis, U+00C4
(entity: 'Aring'; ch: 197; ), // latin capital letter A with ring above = latin capital letter A ring, U+00C5
(entity: 'AElig'; ch: 198; ), // latin capital letter AE = latin capital ligature AE, U+00C6
(entity: 'Ccedil'; ch: 199; ), // latin capital letter C with cedilla, U+00C7
(entity: 'Egrave'; ch: 200; ), // latin capital letter E with grave, U+00C8
(entity: 'Eacute'; ch: 201; ), // latin capital letter E with acute, U+00C9
(entity: 'Ecirc'; ch: 202; ), // latin capital letter E with circumflex, U+00CA
(entity: 'Euml'; ch: 203; ), // latin capital letter E with diaeresis, U+00CB
(entity: 'Igrave'; ch: 204; ), // latin capital letter I with grave, U+00CC
(entity: 'Iacute'; ch: 205; ), // latin capital letter I with acute, U+00CD
(entity: 'Icirc'; ch: 206; ), // latin capital letter I with circumflex, U+00CE
(entity: 'Iuml'; ch: 207; ), // latin capital letter I with diaeresis, U+00CF
(entity: 'ETH'; ch: 208; ), // latin capital letter ETH, U+00D0
(entity: 'Ntilde'; ch: 209; ), // latin capital letter N with tilde, U+00D1
(entity: 'Ograve'; ch: 210; ), // latin capital letter O with grave, U+00D2
(entity: 'Oacute'; ch: 211; ), // latin capital letter O with acute, U+00D3
(entity: 'Ocirc'; ch: 212; ), // latin capital letter O with circumflex, U+00D4
(entity: 'Otilde'; ch: 213; ), // latin capital letter O with tilde, U+00D5
(entity: 'Ouml'; ch: 214; ), // latin capital letter O with diaeresis, U+00D6
(entity: 'times'; ch: 215; ), // multiplication sign, U+00D7
(entity: 'Oslash'; ch: 216; ), // latin capital letter O with stroke = latin capital letter O slash, U+00D8
(entity: 'Ugrave'; ch: 217; ), // latin capital letter U with grave, U+00D9
(entity: 'Uacute'; ch: 218; ), // latin capital letter U with acute, U+00DA
(entity: 'Ucirc'; ch: 219; ), // latin capital letter U with circumflex, U+00DB
(entity: 'Uuml'; ch: 220; ), // latin capital letter U with diaeresis, U+00DC
(entity: 'Yacute'; ch: 221; ), // latin capital letter Y with acute, U+00DD
(entity: 'THORN'; ch: 222; ), // latin capital letter THORN, U+00DE
(entity: 'szlig'; ch: 223; ), // latin small letter sharp s = ess-zed, U+00DF
(entity: 'agrave'; ch: 224; ), // latin small letter a with grave = latin small letter a grave, U+00E0
(entity: 'aacute'; ch: 225; ), // latin small letter a with acute, U+00E1
(entity: 'acirc'; ch: 226; ), // latin small letter a with circumflex, U+00E2
(entity: 'atilde'; ch: 227; ), // latin small letter a with tilde, U+00E3
(entity: 'auml'; ch: 228; ), // latin small letter a with diaeresis, U+00E4
(entity: 'aring'; ch: 229; ), // latin small letter a with ring above = latin small letter a ring, U+00E5
(entity: 'aelig'; ch: 230; ), // latin small letter ae = latin small ligature ae, U+00E6
(entity: 'ccedil'; ch: 231; ), // latin small letter c with cedilla, U+00E7
(entity: 'egrave'; ch: 232; ), // latin small letter e with grave, U+00E8
(entity: 'eacute'; ch: 233; ), // latin small letter e with acute, U+00E9
(entity: 'ecirc'; ch: 234; ), // latin small letter e with circumflex, U+00EA
(entity: 'euml'; ch: 235; ), // latin small letter e with diaeresis, U+00EB
(entity: 'igrave'; ch: 236; ), // latin small letter i with grave, U+00EC
(entity: 'iacute'; ch: 237; ), // latin small letter i with acute, U+00ED
(entity: 'icirc'; ch: 238; ), // latin small letter i with circumflex, U+00EE
(entity: 'iuml'; ch: 239; ), // latin small letter i with diaeresis, U+00EF
(entity: 'eth'; ch: 240; ), // latin small letter eth, U+00F0
(entity: 'ntilde'; ch: 241; ), // latin small letter n with tilde, U+00F1
(entity: 'ograve'; ch: 242; ), // latin small letter o with grave, U+00F2
(entity: 'oacute'; ch: 243; ), // latin small letter o with acute, U+00F3
(entity: 'ocirc'; ch: 244; ), // latin small letter o with circumflex, U+00F4
(entity: 'otilde'; ch: 245; ), // latin small letter o with tilde, U+00F5
(entity: 'ouml'; ch: 246; ), // latin small letter o with diaeresis, U+00F6
(entity: 'divide'; ch: 247; ), // division sign, U+00F7
(entity: 'oslash'; ch: 248; ), // latin small letter o with stroke, = latin small letter o slash, U+00F8
(entity: 'ugrave'; ch: 249; ), // latin small letter u with grave, U+00F9
(entity: 'uacute'; ch: 250; ), // latin small letter u with acute, U+00FA
(entity: 'ucirc'; ch: 251; ), // latin small letter u with circumflex, U+00FB
(entity: 'uuml'; ch: 252; ), // latin small letter u with diaeresis, U+00FC
(entity: 'yacute'; ch: 253; ), // latin small letter y with acute, U+00FD
(entity: 'thorn'; ch: 254; ), // latin small letter thorn, U+00FE
(entity: 'yuml'; ch: 255; ), // latin small letter y with diaeresis, U+00FF
(entity: 'fnof'; ch: 402; ), // latin small f with hook = function = florin, U+0192
(entity: 'Alpha'; ch: 913; ), // greek capital letter alpha, U+0391
(entity: 'Beta'; ch: 914; ), // greek capital letter beta, U+0392
(entity: 'Gamma'; ch: 915; ), // greek capital letter gamma, U+0393
(entity: 'Delta'; ch: 916; ), // greek capital letter delta, U+0394
(entity: 'Epsilon'; ch: 917; ), // greek capital letter epsilon, U+0395
(entity: 'Zeta'; ch: 918; ), // greek capital letter zeta, U+0396
(entity: 'Eta'; ch: 919; ), // greek capital letter eta, U+0397
(entity: 'Theta'; ch: 920; ), // greek capital letter theta, U+0398
(entity: 'Iota'; ch: 921; ), // greek capital letter iota, U+0399
(entity: 'Kappa'; ch: 922; ), // greek capital letter kappa, U+039A
(entity: 'Lambda'; ch: 923; ), // greek capital letter lambda, U+039B
(entity: 'Mu'; ch: 924; ), // greek capital letter mu, U+039C
(entity: 'Nu'; ch: 925; ), // greek capital letter nu, U+039D
(entity: 'Xi'; ch: 926; ), // greek capital letter xi, U+039E
(entity: 'Omicron'; ch: 927; ), // greek capital letter omicron, U+039F
(entity: 'Pi'; ch: 928; ), // greek capital letter pi, U+03A0
(entity: 'Rho'; ch: 929; ), // greek capital letter rho, U+03A1
// there is no Sigmaf, and no U+03A2 character either
(entity: 'Sigma'; ch: 931; ), // greek capital letter sigma, U+03A3
(entity: 'Tau'; ch: 932; ), // greek capital letter tau, U+03A4
(entity: 'Upsilon'; ch: 933; ), // greek capital letter upsilon, U+03A5
(entity: 'Phi'; ch: 934; ), // greek capital letter phi, U+03A6
(entity: 'Chi'; ch: 935; ), // greek capital letter chi, U+03A7
(entity: 'Psi'; ch: 936; ), // greek capital letter psi, U+03A8
(entity: 'Omega'; ch: 937; ), // greek capital letter omega, U+03A9
(entity: 'alpha'; ch: 945; ), // greek small letter alpha, U+03B1
(entity: 'beta'; ch: 946; ), // greek small letter beta, U+03B2
(entity: 'gamma'; ch: 947; ), // greek small letter gamma, U+03B3
(entity: 'delta'; ch: 948; ), // greek small letter delta, U+03B4
(entity: 'epsilon'; ch: 949; ), // greek small letter epsilon, U+03B5
(entity: 'zeta'; ch: 950; ), // greek small letter zeta, U+03B6
(entity: 'eta'; ch: 951; ), // greek small letter eta, U+03B7
(entity: 'theta'; ch: 952; ), // greek small letter theta, U+03B8
(entity: 'iota'; ch: 953; ), // greek small letter iota, U+03B9
(entity: 'kappa'; ch: 954; ), // greek small letter kappa, U+03BA
(entity: 'lambda'; ch: 955; ), // greek small letter lambda, U+03BB
(entity: 'mu'; ch: 956; ), // greek small letter mu, U+03BC
(entity: 'nu'; ch: 957; ), // greek small letter nu, U+03BD
(entity: 'xi'; ch: 958; ), // greek small letter xi, U+03BE
(entity: 'omicron'; ch: 959; ), // greek small letter omicron, U+03BF NEW
(entity: 'pi'; ch: 960; ), // greek small letter pi, U+03C0
(entity: 'rho'; ch: 961; ), // greek small letter rho, U+03C1
(entity: 'sigmaf'; ch: 962; ), // greek small letter final sigma, U+03C2
(entity: 'sigma'; ch: 963; ), // greek small letter sigma, U+03C3
(entity: 'tau'; ch: 964; ), // greek small letter tau, U+03C4
(entity: 'upsilon'; ch: 965; ), // greek small letter upsilon, U+03C5
(entity: 'phi'; ch: 966; ), // greek small letter phi, U+03C6
(entity: 'chi'; ch: 967; ), // greek small letter chi, U+03C7
(entity: 'psi'; ch: 968; ), // greek small letter psi, U+03C8
(entity: 'omega'; ch: 969; ), // greek small letter omega, U+03C9
(entity: 'thetasym'; ch: 977; ), // greek small letter theta symbol, U+03D1 NEW
(entity: 'upsih'; ch: 978; ), // greek upsilon with hook symbol, U+03D2 NEW
(entity: 'piv'; ch: 982; ), // greek pi symbol, U+03D6
(entity: 'bull'; ch: 8226; ), // bullet = black small circle, U+2022
(entity: 'hellip'; ch: 8230; ), // horizontal ellipsis = three dot leader, U+2026
(entity: 'prime'; ch: 8242; ), // prime = minutes = feet, U+2032
(entity: 'Prime'; ch: 8243; ), // double prime = seconds = inches, U+2033
(entity: 'oline'; ch: 8254; ), // overline = spacing overscore, U+203E NEW
(entity: 'frasl'; ch: 8260; ), // fraction slash, U+2044 NEW
(entity: 'ensp'; ch: 8194; ), // en space, U+2002
(entity: 'emsp'; ch: 8195; ), // em space, U+2003
(entity: 'thinsp'; ch: 8201; ), // thin space, U+2009
(entity: 'zwnj'; ch: 8204; ), // zero width non-joiner, U+200C NEW RFC 2070
(entity: 'zwj'; ch: 8205; ), // zero width joiner, U+200D NEW RFC 2070
(entity: 'lrm'; ch: 8206; ), // left-to-right mark, U+200E NEW RFC 2070
(entity: 'rlm'; ch: 8207; ), // right-to-left mark, U+200F NEW RFC 2070
(entity: 'ndash'; ch: 8211; ), // en dash, U+2013
(entity: 'mdash'; ch: 8212; ), // em dash, U+2014
(entity: 'lsquo'; ch: 8216; ), // left single quotation mark, U+2018
(entity: 'rsquo'; ch: 8217; ), // right single quotation mark, U+2019
(entity: 'sbquo'; ch: 8218; ), // single low-9 quotation mark, U+201A NEW
(entity: 'ldquo'; ch: 8220; ), // left double quotation mark, U+201C
(entity: 'rdquo'; ch: 8221; ), // right double quotation mark, U+201D
(entity: 'bdquo'; ch: 8222; ), // double low-9 quotation mark, U+201E NEW
(entity: 'dagger'; ch: 8224; ), // dagger, U+2020
(entity: 'Dagger'; ch: 8225; ), // double dagger, U+2021
(entity: 'permil'; ch: 8240; ), // per mille sign, U+2030
(entity: 'lsaquo'; ch: 8249; ), // single left-pointing angle quotation mark, U+2039
(entity: 'rsaquo'; ch: 8250; ), // single right-pointing angle quotation mark, U+203A
(entity: 'euro'; ch: 8364; ), // euro sign, U+20AC NEW
(entity: 'weierp'; ch: 8472; ), // script capital P = power set = Weierstrass p, U+2118
(entity: 'image'; ch: 8465; ), // blackletter capital I = imaginary part, U+2111
(entity: 'real'; ch: 8476; ), // blackletter capital R = real part symbol, U+211C
(entity: 'trade'; ch: 8482; ), // trade mark sign, U+2122
(entity: 'alefsym'; ch: 8501; ), // alef symbol = first transfinite cardinal, U+2135 NEW (alef symbol is NOT the same as hebrew letter alef, U+05D0 although the same glyph could be used to depict both characters)
(entity: 'larr'; ch: 8592; ), // leftwards arrow, U+2190
(entity: 'uarr'; ch: 8593; ), // upwards arrow, U+2191
(entity: 'rarr'; ch: 8594; ), // rightwards arrow, U+2192
(entity: 'darr'; ch: 8595; ), // downwards arrow, U+2193
(entity: 'harr'; ch: 8596; ), // left right arrow, U+2194
(entity: 'crarr'; ch: 8629; ), // downwards arrow with corner leftwards = carriage return, U+21B5 NEW
(entity: 'lArr'; ch: 8656; ), // leftwards double arrow, U+21D0
(entity: 'uArr'; ch: 8657; ), // upwards double arrow, U+21D1
(entity: 'rArr'; ch: 8658; ), // rightwards double arrow, U+21D2
(entity: 'dArr'; ch: 8659; ), // downwards double arrow, U+21D3
(entity: 'hArr'; ch: 8660; ), // left right double arrow, U+21D4
(entity: 'forall'; ch: 8704; ), // for all, U+2200
(entity: 'part'; ch: 8706; ), // partial differential, U+2202
(entity: 'exist'; ch: 8707; ), // there exists, U+2203
(entity: 'empty'; ch: 8709; ), // empty set = null set = diameter, U+2205
(entity: 'nabla'; ch: 8711; ), // nabla = backward difference, U+2207
(entity: 'isin'; ch: 8712; ), // element of, U+2208
(entity: 'notin'; ch: 8713; ), // not an element of, U+2209
(entity: 'ni'; ch: 8715; ), // contains as member, U+220B
(entity: 'prod'; ch: 8719; ), // n-ary product = product sign, U+220F
(entity: 'sum'; ch: 8721; ), // n-ary sumation, U+2211
(entity: 'minus'; ch: 8722; ), // minus sign, U+2212
(entity: 'lowast'; ch: 8727; ), // asterisk operator, U+2217
(entity: 'radic'; ch: 8730; ), // square root = radical sign, U+221A
(entity: 'prop'; ch: 8733; ), // proportional to, U+221D
(entity: 'infin'; ch: 8734; ), // infinity, U+221E
(entity: 'ang'; ch: 8736; ), // angle, U+2220
(entity: 'and'; ch: 8743; ), // logical and = wedge, U+2227
(entity: 'or'; ch: 8744; ), // logical or = vee, U+2228
(entity: 'cap'; ch: 8745; ), // intersection = cap, U+2229
(entity: 'cup'; ch: 8746; ), // union = cup, U+222A
(entity: 'int'; ch: 8747; ), // integral, U+222B
(entity: 'there4'; ch: 8756; ), // therefore, U+2234
(entity: 'sim'; ch: 8764; ), // tilde operator = varies with = similar to, U+223C
(entity: 'cong'; ch: 8773; ), // approximately equal to, U+2245
(entity: 'asymp'; ch: 8776; ), // almost equal to = asymptotic to, U+2248
(entity: 'ne'; ch: 8800; ), // not equal to, U+2260
(entity: 'equiv'; ch: 8801; ), // identical to, U+2261
(entity: 'le'; ch: 8804; ), // less-than or equal to, U+2264
(entity: 'ge'; ch: 8805; ), // greater-than or equal to, U+2265
(entity: 'sub'; ch: 8834; ), // subset of, U+2282
(entity: 'sup'; ch: 8835; ), // superset of, U+2283
(entity: 'nsub'; ch: 8836; ), // not a subset of, U+2284
(entity: 'sube'; ch: 8838; ), // subset of or equal to, U+2286
(entity: 'supe'; ch: 8839; ), // superset of or equal to, U+2287
(entity: 'oplus'; ch: 8853; ), // circled plus = direct sum, U+2295
(entity: 'otimes'; ch: 8855; ), // circled times = vector product, U+2297
(entity: 'perp'; ch: 8869; ), // up tack = orthogonal to = perpendicular, U+22A5
(entity: 'sdot'; ch: 8901; ), // dot operator, U+22C5
(entity: 'lceil'; ch: 8968; ), // left ceiling = apl upstile, U+2308
(entity: 'rceil'; ch: 8969; ), // right ceiling, U+2309
(entity: 'lfloor'; ch: 8970; ), // left floor = apl downstile, U+230A
(entity: 'rfloor'; ch: 8971; ), // right floor, U+230B
(entity: 'lang'; ch: 9001; ), // left-pointing angle bracket = bra, U+2329
(entity: 'rang'; ch: 9002; ), // right-pointing angle bracket = ket, U+232A
(entity: 'loz'; ch: 9674; ), // lozenge, U+25CA
(entity: 'spades'; ch: 9824; ), // black spade suit, U+2660
(entity: 'clubs'; ch: 9827; ), // black club suit = shamrock, U+2663
(entity: 'hearts'; ch: 9829; ), // black heart suit = valentine, U+2665
(entity: 'diams'; ch: 9830; ) // black diamond suit, U+2666
);
var
i: Integer;
len: Integer;
nChar: UCS4Char;
runEntity: string;
begin
{
EntityRef ::= '&' Name ';'
Name ::= NameStartChar (NameChar)*
NameStartChar ::= ":" | [A-Z] | "_" | [a-z] | [#xC0-#xD6] | [#xD8-#xF6] | [#xF8-#x2FF] | [#x370-#x37D] | [#x37F-#x1FFF] | [#x200C-#x200D] | [#x2070-#x218F] | [#x2C00-#x2FEF] | [#x3001-#xD7FF] | [#xF900-#xFDCF] | [#xFDF0-#xFFFD] | [#x10000-#xEFFFF]
NameChar ::= NameStartChar | "-" | "." | [0-9] | #xB7 | [#x0300-#x036F] | [#x203F-#x2040]
}
Result := '';
CharRef := '';
len := Length(sValue) - StartIndex + 1;
if len < 4 then
Exit;
i := StartIndex;
if sValue[i] <> '&' then Exit;
Inc(i);
if not IsNameStartChar(sValue[i]) then
Exit;
Inc(i);
while IsNameChar(sValue[i]) do
begin
Inc(i);
if i > Length(sValue) then
Exit;
end;
if sValue[i] <> ';' then
Exit;
charRef := Copy(sValue, StartIndex, (i-StartIndex)+1);
//Strip off the & and ;
runEntity := Copy(charRef, 2, Length(charRef)-2);
for i := Low(HtmlEntities) to High(HtmlEntities) do
begin
//Case sensitive check; as entites are case sensitive
if runEntity = HtmlEntities[i].entity then
begin
nChar := HtmlEntities[i].ch;
Result := UCS4CharToString(nChar);
Exit;
end;
end;
//It looks like a valid entity reference, but we don't recognize the text.
//It's probably garbage that we might be able to fix
if IsDebuggerPresent then
OutputDebugString(PChar('HtmlDecode: Unknown HTML entity reference: "'+charRef+'"'));
end;
var
i: Integer;
entity: UnicodeString;
entityChar: UnicodeString;
begin
i := 1;
Result := '';
while i <= Length(s) do
begin
if s[i] <> '&' then
begin
Result := Result + s[i];
Inc(i);
Continue;
end;
entityChar := GetCharRef(s, i, {out}entity);
if entityChar <> '' then
begin
Result := Result + entityChar;
Inc(i, Length(entity));
Continue;
end;
entityChar := GetEntityRef(s, i, {out}entity);
if entityChar <> '' then
begin
Result := Result + entityChar;
Inc(i, Length(entity));
Continue;
end;
Result := Result + s[i];
Inc(i);
end;
end;
Ian Boyd
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- 1,219
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There seems to be a non-terminated comment at the beginning of the routine. – Andreas Rejbrand May 16 '20 at 23:28
4
Here's my HTMLDecode procedure (slightly modified from CGs HTTPApp unit):
function HTMLDecode(const AStr: String): String;
var
Sp, Rp, Cp, Tp: PChar;
S: String;
I, Code: Integer;
begin
SetLength(Result, Length(AStr));
Sp := PChar(AStr);
Rp := PChar(Result);
Cp := Sp;
try
while Sp^ <> #0 do
begin
case Sp^ of
'&': begin
Cp := Sp;
Inc(Sp);
case Sp^ of
'a': if AnsiStrPos(Sp, 'amp;') = Sp then { do not localize }
begin
Inc(Sp, 3);
Rp^ := '&';
end;
'l',
'g': if (AnsiStrPos(Sp, 'lt;') = Sp) or (AnsiStrPos(Sp, 'gt;') = Sp) then { do not localize }
begin
Cp := Sp;
Inc(Sp, 2);
while (Sp^ <> ';') and (Sp^ <> #0) do
Inc(Sp);
if Cp^ = 'l' then
Rp^ := '<'
else
Rp^ := '>';
end;
'n': if AnsiStrPos(Sp, 'nbsp;') = Sp then { do not localize }
begin
Inc(Sp, 4);
Rp^ := ' ';
end;
'q': if AnsiStrPos(Sp, 'quot;') = Sp then { do not localize }
begin
Inc(Sp,4);
Rp^ := '"';
end;
'#': begin
Tp := Sp;
Inc(Tp);
while (Sp^ <> ';') and (Sp^ <> #0) do
Inc(Sp);
SetString(S, Tp, Sp - Tp);
Val(S, I, Code);
Rp^ := Chr((I));
end;
else
Exit;
end;
end
else
Rp^ := Sp^;
end;
Inc(Rp);
Inc(Sp);
end;
except
end;
SetLength(Result, Rp - PChar(Result));
end;
invarbrass
- 49
- 1
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The function of the same name in the provided unit HTTPApp doesn't handle the token. This is based on that code, but does. – MarkAurelius Oct 28 '15 at 03:10
-
WARNING: this function leads to buffer overflow. If the string contains "&&&", it leads to "Exit" function, this skips SetLength and Result buffer length remains with incorrect data! You have been warned. – smooty86 Feb 27 '20 at 18:52
-
There are much more entities that exist which aren't handled by this function (i.e. `'`, `•`, `©`...). Nor is `#x5bce;` supported – AmigoJack Apr 09 '20 at 12:28
-4
This is a prototype function. Didn't check the validity. Just absorb the idea.
function HtmlDecode(const AStr: string) : char;
var
iPos : integer;
begin
iPos := AnsiPos(';', AStr);
Result := Chr(StrToInt(Copy(AStr, 3, iPos)));
end;
Bye!
Olaf
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