I'm trying to convert some strings that are in Czech, Spanish, French etc. I'd like to take out the accent marks in the letters while keeping the letter. (E.g. convert é to e, č to c, Ž to Z, ñ to n)
What is the best way to achieve this?
Btw, there is a good similar question/answer for JavaScript
Not throughougly tested but seems to work
void main() {
var paragraph = "L'avantage d'utiliser le lorem ipsum est bien évidemment de pouvoir créer des maquettes ou de remplir un site internet de contenus qui présentent un rendu s'approchant un maximum du rendu final. \n Par défaut lorem ipsum ne contient pas d'accent ni de caractères spéciaux contrairement à la langue française qui en contient beaucoup. C'est sur ce critère que nous proposons une solution avec cet outil qui générant du faux-texte lorem ipsum mais avec en plus, des caractères spéciaux tel que les accents ou certains symboles utiles pour la langue française. \n L'utilisation du lorem standard est facile d’utilisation mais lorsque le futur client utilisera votre logiciel il se peut que certains caractères spéciaux ou qu'un accent ne soient pas codés correctement. \n Cette page a pour but donc de pouvoir perdre le moins de temps possible et donc de tester directement si tous les encodages de base de donnée ou des sites sont les bons de plus il permet de récuperer un code css avec le texte formaté !";
print(removeDiacritics(paragraph));
}
final defaultDiacriticsRemovalap = [
{'base':'A', 'letters':'\u0041\u24B6\uFF21\u00C0\u00C1\u00C2\u1EA6\u1EA4\u1EAA\u1EA8\u00C3\u0100\u0102\u1EB0\u1EAE\u1EB4\u1EB2\u0226\u01E0\u00C4\u01DE\u1EA2\u00C5\u01FA\u01CD\u0200\u0202\u1EA0\u1EAC\u1EB6\u1E00\u0104\u023A\u2C6F'},
{'base':'AA','letters':'\uA732'},
{'base':'AE','letters':'\u00C6\u01FC\u01E2'},
{'base':'AO','letters':'\uA734'},
{'base':'AU','letters':'\uA736'},
{'base':'AV','letters':'\uA738\uA73A'},
{'base':'AY','letters':'\uA73C'},
{'base':'B', 'letters':'\u0042\u24B7\uFF22\u1E02\u1E04\u1E06\u0243\u0182\u0181'},
{'base':'C', 'letters':'\u0043\u24B8\uFF23\u0106\u0108\u010A\u010C\u00C7\u1E08\u0187\u023B\uA73E'},
{'base':'D', 'letters':'\u0044\u24B9\uFF24\u1E0A\u010E\u1E0C\u1E10\u1E12\u1E0E\u0110\u018B\u018A\u0189\uA779'},
{'base':'DZ','letters':'\u01F1\u01C4'},
{'base':'Dz','letters':'\u01F2\u01C5'},
{'base':'E', 'letters':'\u0045\u24BA\uFF25\u00C8\u00C9\u00CA\u1EC0\u1EBE\u1EC4\u1EC2\u1EBC\u0112\u1E14\u1E16\u0114\u0116\u00CB\u1EBA\u011A\u0204\u0206\u1EB8\u1EC6\u0228\u1E1C\u0118\u1E18\u1E1A\u0190\u018E'},
{'base':'F', 'letters':'\u0046\u24BB\uFF26\u1E1E\u0191\uA77B'},
{'base':'G', 'letters':'\u0047\u24BC\uFF27\u01F4\u011C\u1E20\u011E\u0120\u01E6\u0122\u01E4\u0193\uA7A0\uA77D\uA77E'},
{'base':'H', 'letters':'\u0048\u24BD\uFF28\u0124\u1E22\u1E26\u021E\u1E24\u1E28\u1E2A\u0126\u2C67\u2C75\uA78D'},
{'base':'I', 'letters':'\u0049\u24BE\uFF29\u00CC\u00CD\u00CE\u0128\u012A\u012C\u0130\u00CF\u1E2E\u1EC8\u01CF\u0208\u020A\u1ECA\u012E\u1E2C\u0197'},
{'base':'J', 'letters':'\u004A\u24BF\uFF2A\u0134\u0248'},
{'base':'K', 'letters':'\u004B\u24C0\uFF2B\u1E30\u01E8\u1E32\u0136\u1E34\u0198\u2C69\uA740\uA742\uA744\uA7A2'},
{'base':'L', 'letters':'\u004C\u24C1\uFF2C\u013F\u0139\u013D\u1E36\u1E38\u013B\u1E3C\u1E3A\u0141\u023D\u2C62\u2C60\uA748\uA746\uA780'},
{'base':'LJ','letters':'\u01C7'},
{'base':'Lj','letters':'\u01C8'},
{'base':'M', 'letters':'\u004D\u24C2\uFF2D\u1E3E\u1E40\u1E42\u2C6E\u019C'},
{'base':'N', 'letters':'\u004E\u24C3\uFF2E\u01F8\u0143\u00D1\u1E44\u0147\u1E46\u0145\u1E4A\u1E48\u0220\u019D\uA790\uA7A4'},
{'base':'NJ','letters':'\u01CA'},
{'base':'Nj','letters':'\u01CB'},
{'base':'O', 'letters':'\u004F\u24C4\uFF2F\u00D2\u00D3\u00D4\u1ED2\u1ED0\u1ED6\u1ED4\u00D5\u1E4C\u022C\u1E4E\u014C\u1E50\u1E52\u014E\u022E\u0230\u00D6\u022A\u1ECE\u0150\u01D1\u020C\u020E\u01A0\u1EDC\u1EDA\u1EE0\u1EDE\u1EE2\u1ECC\u1ED8\u01EA\u01EC\u00D8\u01FE\u0186\u019F\uA74A\uA74C'},
{'base':'OI','letters':'\u01A2'},
{'base':'OO','letters':'\uA74E'},
{'base':'OU','letters':'\u0222'},
{'base':'OE','letters':'\u008C\u0152'},
{'base':'oe','letters':'\u009C\u0153'},
{'base':'P', 'letters':'\u0050\u24C5\uFF30\u1E54\u1E56\u01A4\u2C63\uA750\uA752\uA754'},
{'base':'Q', 'letters':'\u0051\u24C6\uFF31\uA756\uA758\u024A'},
{'base':'R', 'letters':'\u0052\u24C7\uFF32\u0154\u1E58\u0158\u0210\u0212\u1E5A\u1E5C\u0156\u1E5E\u024C\u2C64\uA75A\uA7A6\uA782'},
{'base':'S', 'letters':'\u0053\u24C8\uFF33\u1E9E\u015A\u1E64\u015C\u1E60\u0160\u1E66\u1E62\u1E68\u0218\u015E\u2C7E\uA7A8\uA784'},
{'base':'T', 'letters':'\u0054\u24C9\uFF34\u1E6A\u0164\u1E6C\u021A\u0162\u1E70\u1E6E\u0166\u01AC\u01AE\u023E\uA786'},
{'base':'TZ','letters':'\uA728'},
{'base':'U', 'letters':'\u0055\u24CA\uFF35\u00D9\u00DA\u00DB\u0168\u1E78\u016A\u1E7A\u016C\u00DC\u01DB\u01D7\u01D5\u01D9\u1EE6\u016E\u0170\u01D3\u0214\u0216\u01AF\u1EEA\u1EE8\u1EEE\u1EEC\u1EF0\u1EE4\u1E72\u0172\u1E76\u1E74\u0244'},
{'base':'V', 'letters':'\u0056\u24CB\uFF36\u1E7C\u1E7E\u01B2\uA75E\u0245'},
{'base':'VY','letters':'\uA760'},
{'base':'W', 'letters':'\u0057\u24CC\uFF37\u1E80\u1E82\u0174\u1E86\u1E84\u1E88\u2C72'},
{'base':'X', 'letters':'\u0058\u24CD\uFF38\u1E8A\u1E8C'},
{'base':'Y', 'letters':'\u0059\u24CE\uFF39\u1EF2\u00DD\u0176\u1EF8\u0232\u1E8E\u0178\u1EF6\u1EF4\u01B3\u024E\u1EFE'},
{'base':'Z', 'letters':'\u005A\u24CF\uFF3A\u0179\u1E90\u017B\u017D\u1E92\u1E94\u01B5\u0224\u2C7F\u2C6B\uA762'},
{'base':'a', 'letters':'\u0061\u24D0\uFF41\u1E9A\u00E0\u00E1\u00E2\u1EA7\u1EA5\u1EAB\u1EA9\u00E3\u0101\u0103\u1EB1\u1EAF\u1EB5\u1EB3\u0227\u01E1\u00E4\u01DF\u1EA3\u00E5\u01FB\u01CE\u0201\u0203\u1EA1\u1EAD\u1EB7\u1E01\u0105\u2C65\u0250'},
{'base':'aa','letters':'\uA733'},
{'base':'ae','letters':'\u00E6\u01FD\u01E3'},
{'base':'ao','letters':'\uA735'},
{'base':'au','letters':'\uA737'},
{'base':'av','letters':'\uA739\uA73B'},
{'base':'ay','letters':'\uA73D'},
{'base':'b', 'letters':'\u0062\u24D1\uFF42\u1E03\u1E05\u1E07\u0180\u0183\u0253'},
{'base':'c', 'letters':'\u0063\u24D2\uFF43\u0107\u0109\u010B\u010D\u00E7\u1E09\u0188\u023C\uA73F\u2184'},
{'base':'d', 'letters':'\u0064\u24D3\uFF44\u1E0B\u010F\u1E0D\u1E11\u1E13\u1E0F\u0111\u018C\u0256\u0257\uA77A'},
{'base':'dz','letters':'\u01F3\u01C6'},
{'base':'e', 'letters':'\u0065\u24D4\uFF45\u00E8\u00E9\u00EA\u1EC1\u1EBF\u1EC5\u1EC3\u1EBD\u0113\u1E15\u1E17\u0115\u0117\u00EB\u1EBB\u011B\u0205\u0207\u1EB9\u1EC7\u0229\u1E1D\u0119\u1E19\u1E1B\u0247\u025B\u01DD'},
{'base':'f', 'letters':'\u0066\u24D5\uFF46\u1E1F\u0192\uA77C'},
{'base':'g', 'letters':'\u0067\u24D6\uFF47\u01F5\u011D\u1E21\u011F\u0121\u01E7\u0123\u01E5\u0260\uA7A1\u1D79\uA77F'},
{'base':'h', 'letters':'\u0068\u24D7\uFF48\u0125\u1E23\u1E27\u021F\u1E25\u1E29\u1E2B\u1E96\u0127\u2C68\u2C76\u0265'},
{'base':'hv','letters':'\u0195'},
{'base':'i', 'letters':'\u0069\u24D8\uFF49\u00EC\u00ED\u00EE\u0129\u012B\u012D\u00EF\u1E2F\u1EC9\u01D0\u0209\u020B\u1ECB\u012F\u1E2D\u0268\u0131'},
{'base':'j', 'letters':'\u006A\u24D9\uFF4A\u0135\u01F0\u0249'},
{'base':'k', 'letters':'\u006B\u24DA\uFF4B\u1E31\u01E9\u1E33\u0137\u1E35\u0199\u2C6A\uA741\uA743\uA745\uA7A3'},
{'base':'l', 'letters':'\u006C\u24DB\uFF4C\u0140\u013A\u013E\u1E37\u1E39\u013C\u1E3D\u1E3B\u017F\u0142\u019A\u026B\u2C61\uA749\uA781\uA747'},
{'base':'lj','letters':'\u01C9'},
{'base':'m', 'letters':'\u006D\u24DC\uFF4D\u1E3F\u1E41\u1E43\u0271\u026F'},
{'base':'n', 'letters':'\u006E\u24DD\uFF4E\u01F9\u0144\u00F1\u1E45\u0148\u1E47\u0146\u1E4B\u1E49\u019E\u0272\u0149\uA791\uA7A5'},
{'base':'nj','letters':'\u01CC'},
{'base':'o', 'letters':'\u006F\u24DE\uFF4F\u00F2\u00F3\u00F4\u1ED3\u1ED1\u1ED7\u1ED5\u00F5\u1E4D\u022D\u1E4F\u014D\u1E51\u1E53\u014F\u022F\u0231\u00F6\u022B\u1ECF\u0151\u01D2\u020D\u020F\u01A1\u1EDD\u1EDB\u1EE1\u1EDF\u1EE3\u1ECD\u1ED9\u01EB\u01ED\u00F8\u01FF\u0254\uA74B\uA74D\u0275'},
{'base':'oi','letters':'\u01A3'},
{'base':'ou','letters':'\u0223'},
{'base':'oo','letters':'\uA74F'},
{'base':'p','letters':'\u0070\u24DF\uFF50\u1E55\u1E57\u01A5\u1D7D\uA751\uA753\uA755'},
{'base':'q','letters':'\u0071\u24E0\uFF51\u024B\uA757\uA759'},
{'base':'r','letters':'\u0072\u24E1\uFF52\u0155\u1E59\u0159\u0211\u0213\u1E5B\u1E5D\u0157\u1E5F\u024D\u027D\uA75B\uA7A7\uA783'},
{'base':'s','letters':'\u0073\u24E2\uFF53\u00DF\u015B\u1E65\u015D\u1E61\u0161\u1E67\u1E63\u1E69\u0219\u015F\u023F\uA7A9\uA785\u1E9B'},
{'base':'t','letters':'\u0074\u24E3\uFF54\u1E6B\u1E97\u0165\u1E6D\u021B\u0163\u1E71\u1E6F\u0167\u01AD\u0288\u2C66\uA787'},
{'base':'tz','letters':'\uA729'},
{'base':'u','letters': '\u0075\u24E4\uFF55\u00F9\u00FA\u00FB\u0169\u1E79\u016B\u1E7B\u016D\u00FC\u01DC\u01D8\u01D6\u01DA\u1EE7\u016F\u0171\u01D4\u0215\u0217\u01B0\u1EEB\u1EE9\u1EEF\u1EED\u1EF1\u1EE5\u1E73\u0173\u1E77\u1E75\u0289'},
{'base':'v','letters':'\u0076\u24E5\uFF56\u1E7D\u1E7F\u028B\uA75F\u028C'},
{'base':'vy','letters':'\uA761'},
{'base':'w','letters':'\u0077\u24E6\uFF57\u1E81\u1E83\u0175\u1E87\u1E85\u1E98\u1E89\u2C73'},
{'base':'x','letters':'\u0078\u24E7\uFF58\u1E8B\u1E8D'},
{'base':'y','letters':'\u0079\u24E8\uFF59\u1EF3\u00FD\u0177\u1EF9\u0233\u1E8F\u00FF\u1EF7\u1E99\u1EF5\u01B4\u024F\u1EFF'},
{'base':'z','letters':'\u007A\u24E9\uFF5A\u017A\u1E91\u017C\u017E\u1E93\u1E95\u01B6\u0225\u0240\u2C6C\uA763'}
];
final diacriticsMap = {};
final diacriticsRegExp = RegExp('[^\u0000-\u007E]', multiLine: true);
String removeDiacritics(String str) {
if(diacriticsMap.isEmpty) {
for (int i = 0; i < defaultDiacriticsRemovalap.length; i++){
var letters = defaultDiacriticsRemovalap[i]['letters'];
for (int j = 0; j < letters.length; j++) {
diacriticsMap[letters[j]] = defaultDiacriticsRemovalap[i]['base'];
}
}
}
return str.replaceAllMapped(diacriticsRegExp, (a){
return diacriticsMap[a.group(0)] ?? a.group(0);
});
}
Try it at DartPad
Another simple solution that worked for me:
String removeDiacritics(String str) {
var withDia = 'ÀÁÂÃÄÅàáâãäåÒÓÔÕÕÖØòóôõöøÈÉÊËèéêëðÇçÐÌÍÎÏìíîïÙÚÛÜùúûüÑñŠšŸÿýŽž';
var withoutDia = 'AAAAAAaaaaaaOOOOOOOooooooEEEEeeeeeCcDIIIIiiiiUUUUuuuuNnSsYyyZz';
for (int i = 0; i < withDia.length; i++) {
str = str.replaceAll(withDia[i], withoutDia[i]);
}
return str;
}
Here's my adaptation of Leonardo's solution. It extends the string class for ease of use and uses SplitMapJoin instead of a for loop:
extension DiacriticsAwareString on String {
static const diacritics =
'ÀÁÂÃÄÅàáâãäåÒÓÔÕÕÖØòóôõöøÈÉÊËĚèéêëěðČÇçčÐĎďÌÍÎÏìíîïĽľÙÚÛÜŮùúûüůŇÑñňŘřŠšŤťŸÝÿýŽž';
static const nonDiacritics =
'AAAAAAaaaaaaOOOOOOOooooooEEEEEeeeeeeCCccDDdIIIIiiiiLlUUUUUuuuuuNNnnRrSsTtYYyyZz';
String get withoutDiacriticalMarks => this.splitMapJoin('',
onNonMatch: (char) => char.isNotEmpty && diacritics.contains(char)
? nonDiacritics[diacritics.indexOf(char)]
: char);
}
use just the library to make diacritic strings: https://pub.dev/packages/diacritic
Example from the docs:
import 'package:diacritic/diacritic.dart';
main() {
// prints 'arvizturo tukorfurogep'
print(removeDiacritics('árvíztűrő tükörfúrógép'));
}
This is a slightly more flexible solution. it uses replaceAllMapped and has the advantages to replace also continuations symbols such ææ æ with ae
extension StringExtensions on String {
String replaceAllDiacritics() {
return replaceAllMapped(
RegExp('[À-ž]'),
(m) => diacriticsMapping[m.group(0)] ?? '',
);
}
// put here your mapping, this cover chars corresponding to regex [À-ž]
static const diacriticsMapping = {
//[À-ÿ]
'À': 'A',
'Á': 'A',
'Â': 'A',
'Ã': 'A',
'Ä': 'A',
'Å': 'A',
'Æ': 'AE',
'Ç': 'C',
'È': 'E',
'É': 'E',
'Ê': 'E',
'Ë': 'E',
'Ì': 'I',
'Í': 'I',
'Î': 'I',
'Ï': 'I',
'Ð': 'D',
'Ñ': 'N',
'Ò': 'O',
'Ó': 'O',
'Ô': 'O',
'Õ': 'O',
'Ö': 'O',
'×': 'x', //math multiplication
'Ø': 'O',
'Ù': 'U',
'Ú': 'U',
'Û': 'U',
'Ü': 'U',
'Ý': 'Y',
'Þ': 'TH',
'ß': 'SS',
'à': 'a',
'á': 'a',
'â': 'a',
'ã': 'a',
'ä': 'a',
'å': 'a',
'æ': 'ae',
'ç': 'c',
'è': 'e',
'é': 'e',
'ê': 'e',
'ë': 'e',
'ì': 'i',
'í': 'i',
'î': 'i',
'ï': 'i',
'ð': 'd',
'ñ': 'n',
'ò': 'o',
'ó': 'o',
'ô': 'o',
'õ': 'o',
'ö': 'o',
'÷': ' ', //math division
'ø': 'o',
'ù': 'u',
'ú': 'u',
'û': 'u',
'ü': 'u',
'ý': 'y',
'þ': 'th',
'ÿ': 'y',
//[Ā-ž] EuropeanLatin
'Ā': 'A',
'ā': 'a',
'Ă': 'A',
'ă': 'a',
'Ą': 'A',
'ą': 'a',
'Ć': 'C',
'ć': 'c',
'Ĉ': 'C',
'ĉ': 'c',
'Ċ': 'C',
'ċ': 'c',
'Č': 'C',
'č': 'c',
'Ď': 'D',
'ď': 'd',
'Đ': 'D',
'đ': 'd',
'Ē': 'E',
'ē': 'e',
'Ĕ': 'E',
'ĕ': 'e',
'Ė': 'E',
'ė': 'e',
'Ę': 'E',
'ę': 'e',
'Ě': 'E',
'ě': 'e',
'Ĝ': 'G',
'ĝ': 'g',
'Ğ': 'G',
'ğ': 'g',
'Ġ': 'G',
'ġ': 'g',
'Ģ': 'G',
'ģ': 'g',
'Ĥ': 'H',
'ĥ': 'h',
'Ħ': 'H',
'ħ': 'h',
'Ĩ': 'I',
'ĩ': 'i',
'Ī': 'I',
'ī': 'i',
'Ĭ': 'I',
'ĭ': 'i',
'Į': 'I',
'į': 'i',
'İ': 'I',
'ı': 'i',
'IJ': 'IJ',
'ij': 'ij',
'Ĵ': 'J',
'ĵ': 'j',
'Ķ': 'K',
'ķ': 'k',
'ĸ': 'k',
'Ĺ': 'L',
'ĺ': 'l',
'Ļ': 'L',
'ļ': 'l',
'Ľ': 'L',
'ľ': 'l',
'Ŀ': 'L',
'ŀ': 'l',
'Ł': 'L',
'ł': 'l',
'Ń': 'N',
'ń': 'n',
'Ņ': 'N',
'ņ': 'n',
'Ň': 'N',
'ň': 'n',
'ʼn': 'n',
'Ŋ': 'N',
'ŋ': 'n',
'Ō': 'O',
'ō': 'o',
'Ŏ': 'O',
'ŏ': 'o',
'Ő': 'O',
'ő': 'o',
'Œ': 'OE',
'œ': 'oe',
'Ŕ': 'R',
'ŕ': 'r',
'Ŗ': 'R',
'ŗ': 'r',
'Ř': 'R',
'ř': 'r',
'Ś': 'S',
'ś': 's',
'Ŝ': 'S',
'ŝ': 's',
'Ş': 'S',
'ş': 's',
'Š': 'S',
'š': 's',
'Ţ': 'T',
'ţ': 't',
'Ť': 'T',
'ť': 't',
'Ŧ': 'T',
'ŧ': 't',
'Ũ': 'U',
'ũ': 'u',
'Ū': 'U',
'ū': 'u',
'Ŭ': 'U',
'ŭ': 'u',
'Ů': 'U',
'ů': 'u',
'Ű': 'U',
'ű': 'u',
'Ų': 'U',
'ų': 'u',
'Ŵ': 'W',
'ŵ': 'w',
'Ŷ': 'Y',
'ŷ': 'y',
'Ÿ': 'Y',
'Ź': 'Z',
'ź': 'z',
'Ż': 'Z',
'ż': 'z',
'Ž': 'Z',
'ž': 'z',
};
