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
On
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'));
}
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);
}
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',
};
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;
}
Not throughougly tested but seems to work
Try it at DartPad
See also https://pub.dartlang.org/packages/diacritic