jQuery DataTables - Accent-Insensitive Alphabetization and Searching

Question 1

You are so close in your edit, what you have tried, except that you lack the must important thing : Defining the "scope" or sType of your filter plugin. The function is never called, right? This is because the plugin is not associated with a sType.

To get your code to work simply declare the plugin like this :

$.fn.dataTableExt.ofnSearch['string'] = function ( data ) {
return ! data ?
    '' :
    typeof data === 'string' ?
..
..
}

See this fiddle -> http://jsfiddle.net/Y5ycM/ I have turned some "Internet Explorer" columns into "Internet éxplorer", some "Opera" to "öpera" etc, Try search for ex or op.

See https://datatables.net/development/filtering, section "Type based column filtering " :

When you assign the sType for a column (or have it automatically detected for you by DataTables or a type detection plug-in), you will typically be using this for custom sorting, but it can also be used to provide custom filtering options. This is done by adding functions to the the object with a parameter name which matches the sType for that target column:

I guess there here is a typo or oversight in the documentation, it says

$.fn.dataTableExt.ofnSearch but should correctly be $.fn.dataTableExt.ofnSearch[sType], as the example just after clearly points out.

Update. Allan Jardine confirms this is a bug in 1.9.4 here :

Yup - bug in 1.9.4. 1.9.4 broke this part of the code unfortunately. It also effects the removal of HTML tags from the filter, since that was using the same mechanism. It is fixed in the 1.10 betas though.

Question 2

jQuery v: 2.1.0
jquery.dataTables.min.js v: 1.10.7
dataTables.responsive.min.js v: 1.0.6

I used the accent neutralise plugin from here (thanks Allan Jardine):
http://www.datatables.net/plug-ins/filtering/type-based/accent-neutralise

And just made minimal adaptations for my purposes:

I made an example combining the answers in: http://jsfiddle.net/xebtyaeL/5/

jQuery.fn.DataTable.ext.type.search.string = function ( data ) {
    return ! data ?
        '' :
        typeof data === 'string' ?
            data
                .replace( /έ/g, 'ε')
                .replace( /ύ/g, 'υ')
                .replace( /ό/g, 'ο')
                .replace( /ώ/g, 'ω')
                .replace( /ά/g, 'α')
                .replace( /ί/g, 'ι')
                .replace( /ή/g, 'η')
                .replace( /\n/g, ' ' )
                .replace( /[áÁ]/g, 'a' )
                .replace( /[éÉ]/g, 'e' )
                .replace( /[íÍ]/g, 'i' )
                .replace( /[óÓ]/g, 'o' )
                .replace( /[úÚ]/g, 'u' )
                .replace( /ê/g, 'e' )
                .replace( /î/g, 'i' )
                .replace( /ô/g, 'o' )
                .replace( /è/g, 'e' )
                .replace( /ï/g, 'i' )
                .replace( /ü/g, 'u' )
                .replace( /ã/g, 'a' )
                .replace( /õ/g, 'o' )
                .replace( /ç/g, 'c' )
                .replace( /ì/g, 'i' ) :
            data;
};

var tabla = jQuery('#datatable-table').dataTable( { } );
          new jQuery.fn.dataTable.Responsive( tabla );

jQuery(document).ready(function() {
      var table = jQuery('#datatable-table').DataTable();

      // Remove accented character from search input as well
      jQuery('#datatable-table_filter input').keyup( function () {
        table
          .search(
            jQuery.fn.DataTable.ext.type.search.string( this.value )
          )
          .draw();
      } );
} );

Question 3

In this topic explain this issuse, the trick is to replace strange characters with a normal character (no accent character). So to speak way.

$.fn.DataTable.ext.type.search.string = function ( data ) {
    return ! data ?
        '' :
        typeof data === 'string' ?
            data
                .replace( /\n/g, " " )
                .replace( /[éêè]/g, 'e' ) :   //<------- remplace éêè by e
            data;
}

There is another example

jQuery.fn.DataTable.ext.type.search.string = function ( data ) {
    return ! data ?
        '' :
        typeof data === 'string' ?
            data
                .replace( /\n/g, ' ' )
                .replace( /á/g, 'a' )
                .replace( /é/g, 'e' )
                .replace( /í/g, 'i' )
                .replace( /ó/g, 'o' )
                .replace( /ú/g, 'u' )
                .replace( /ê/g, 'e' )
                .replace( /î/g, 'i' )
                .replace( /ô/g, 'o' )
                .replace( /è/g, 'e' )
                .replace( /ï/g, 'i' )
                .replace( /ü/g, 'u' )
                .replace( /ç/g, 'c' ) :
            data;
};

Question 4

I think Jean-Sébastien's solution (sorry, I can't just comment yet) is the only one that actually answers the question. If you type "Explorer" or "éxplorer, it should return "Explorer" AND "éxplorer". In previous suggestions, if one typed "éxplorer", the search would return nothing.

The trick is that his solution misses a part in the keyup function.

$('#example_filter input[type=search]').keyup(function () {
    var table = $('#example').DataTable();
    table.search(
    $.fn.DataTable.ext.type.search.string(accents_supr(this.value))
    ).draw();
});

See this fiddle fork for a working demo. http://jsfiddle.net/syvo/caxj9koL/

Question 5

// (Long) list of all accented characters and their folded equivalents
var accent_map = {
'\n':' ','ẚ':'a','Á':'a','á':'a','À':'a','à':'a','Ă':'a','ă':'a','Ắ':'a','ắ':'a','Ằ':'a','ằ':'a','Ẵ':'a','ẵ':'a','Ẳ':'a','ẳ':'a','Â':'a','â':'a','Ấ':'a','ấ':'a','Ầ':'a','ầ':'a','Ẫ':'a','ẫ':'a','Ẩ':'a','ẩ':'a','Ǎ':'a','ǎ':'a','Å':'a','å':'a','Ǻ':'a','ǻ':'a','Ä':'a','ä':'a','Ǟ':'a','ǟ':'a','Ã':'a','ã':'a','Ȧ':'a','ȧ':'a','Ǡ':'a','ǡ':'a','Ą':'a','ą':'a','Ā':'a','ā':'a','Ả':'a','ả':'a','Ȁ':'a','ȁ':'a','Ȃ':'a','ȃ':'a','Ạ':'a','ạ':'a','Ặ':'a','ặ':'a','Ậ':'a','ậ':'a','Ḁ':'a','ḁ':'a','Ⱥ':'a','ⱥ':'a','Ǽ':'a','ǽ':'a','Ǣ':'a','ǣ':'a','Ḃ':'b','ḃ':'b','Ḅ':'b','ḅ':'b','Ḇ':'b','ḇ':'b','Ƀ':'b','ƀ':'b','ᵬ':'b','Ɓ':'b','ɓ':'b','Ƃ':'b','ƃ':'b','Ć':'c','ć':'c','Ĉ':'c','ĉ':'c','Č':'c','č':'c','Ċ':'c','ċ':'c','Ç':'c','ç':'c','Ḉ':'c','ḉ':'c','Ȼ':'c','ȼ':'c','Ƈ':'c','ƈ':'c','ɕ':'c','Ď':'d','ď':'d','Ḋ':'d','ḋ':'d','Ḑ':'d','ḑ':'d','Ḍ':'d','ḍ':'d','Ḓ':'d','ḓ':'d','Ḏ':'d','ḏ':'d','Đ':'d','đ':'d','ᵭ':'d','Ɖ':'d','ɖ':'d','Ɗ':'d','ɗ':'d','Ƌ':'d','ƌ':'d','ȡ':'d','ð':'d','É':'e','Ə':'e','Ǝ':'e','ǝ':'e','é':'e','È':'e','è':'e','Ĕ':'e','ĕ':'e','Ê':'e','ê':'e','Ế':'e','ế':'e','Ề':'e','ề':'e','Ễ':'e','ễ':'e','Ể':'e','ể':'e','Ě':'e','ě':'e','Ë':'e','ë':'e','Ẽ':'e','ẽ':'e','Ė':'e','ė':'e','Ȩ':'e','ȩ':'e','Ḝ':'e','ḝ':'e','Ę':'e','ę':'e','Ē':'e','ē':'e','Ḗ':'e','ḗ':'e','Ḕ':'e','ḕ':'e','Ẻ':'e','ẻ':'e','Ȅ':'e','ȅ':'e','Ȇ':'e','ȇ':'e','Ẹ':'e','ẹ':'e','Ệ':'e','ệ':'e','Ḙ':'e','ḙ':'e','Ḛ':'e','ḛ':'e','Ɇ':'e','ɇ':'e','ɚ':'e','ɝ':'e','Ḟ':'f','ḟ':'f','ᵮ':'f','Ƒ':'f','ƒ':'f','Ǵ':'g','ǵ':'g','Ğ':'g','ğ':'g','Ĝ':'g','ĝ':'g','Ǧ':'g','ǧ':'g','Ġ':'g','ġ':'g','Ģ':'g','ģ':'g','Ḡ':'g','ḡ':'g','Ǥ':'g','ǥ':'g','Ɠ':'g','ɠ':'g','Ĥ':'h','ĥ':'h','Ȟ':'h','ȟ':'h','Ḧ':'h','ḧ':'h','Ḣ':'h','ḣ':'h','Ḩ':'h','ḩ':'h','Ḥ':'h','ḥ':'h','Ḫ':'h','ḫ':'h','H':'h','̱':'h','ẖ':'h','Ħ':'h','ħ':'h','Ⱨ':'h','ⱨ':'h','Í':'i','í':'i','Ì':'i','ì':'i','Ĭ':'i','ĭ':'i','Î':'i','î':'i','Ǐ':'i','ǐ':'i','Ï':'i','ï':'i','Ḯ':'i','ḯ':'i','Ĩ':'i','ĩ':'i','İ':'i','i':'i','Į':'i','į':'i','Ī':'i','ī':'i','Ỉ':'i','ỉ':'i','Ȉ':'i','ȉ':'i','Ȋ':'i','ȋ':'i','Ị':'i','ị':'i','Ḭ':'i','ḭ':'i','I':'i','ı':'i','Ɨ':'i','ɨ':'i','Ĵ':'j','ĵ':'j','J':'j','̌':'j','ǰ':'j','ȷ':'j','Ɉ':'j','ɉ':'j','ʝ':'j','ɟ':'j','ʄ':'j','Ḱ':'k','ḱ':'k','Ǩ':'k','ǩ':'k','Ķ':'k','ķ':'k','Ḳ':'k','ḳ':'k','Ḵ':'k','ḵ':'k','Ƙ':'k','ƙ':'k','Ⱪ':'k','ⱪ':'k','Ĺ':'a','ĺ':'l','Ľ':'l','ľ':'l','Ļ':'l','ļ':'l','Ḷ':'l','ḷ':'l','Ḹ':'l','ḹ':'l','Ḽ':'l','ḽ':'l','Ḻ':'l','ḻ':'l','Ł':'l','ł':'l','Ł':'l','̣':'l','ł':'l','̣':'l','Ŀ':'l','ŀ':'l','Ƚ':'l','ƚ':'l','Ⱡ':'l','ⱡ':'l','Ɫ':'l','ɫ':'l','ɬ':'l','ɭ':'l','ȴ':'l','Ḿ':'m','ḿ':'m','Ṁ':'m','ṁ':'m','Ṃ':'m','ṃ':'m','ɱ':'m','Ń':'n','ń':'n','Ǹ':'n','ǹ':'n','Ň':'n','ň':'n','Ñ':'n','ñ':'n','Ṅ':'n','ṅ':'n','Ņ':'n','ņ':'n','Ṇ':'n','ṇ':'n','Ṋ':'n','ṋ':'n','Ṉ':'n','ṉ':'n','Ɲ':'n','ɲ':'n','Ƞ':'n','ƞ':'n','ɳ':'n','ȵ':'n','N':'n','̈':'n','n':'n','̈':'n','Ó':'o','ó':'o','Ò':'o','ò':'o','Ŏ':'o','ŏ':'o','Ô':'o','ô':'o','Ố':'o','ố':'o','Ồ':'o','ồ':'o','Ỗ':'o','ỗ':'o','Ổ':'o','ổ':'o','Ǒ':'o','ǒ':'o','Ö':'o','ö':'o','Ȫ':'o','ȫ':'o','Ő':'o','ő':'o','Õ':'o','õ':'o','Ṍ':'o','ṍ':'o','Ṏ':'o','ṏ':'o','Ȭ':'o','ȭ':'o','Ȯ':'o','ȯ':'o','Ȱ':'o','ȱ':'o','Ø':'o','ø':'o','Ǿ':'o','ǿ':'o','Ǫ':'o','ǫ':'o','Ǭ':'o','ǭ':'o','Ō':'o','ō':'o','Ṓ':'o','ṓ':'o','Ṑ':'o','ṑ':'o','Ỏ':'o','ỏ':'o','Ȍ':'o','ȍ':'o','Ȏ':'o','ȏ':'o','Ơ':'o','ơ':'o','Ớ':'o','ớ':'o','Ờ':'o','ờ':'o','Ỡ':'o','ỡ':'o','Ở':'o','ở':'o','Ợ':'o','ợ':'o','Ọ':'o','ọ':'o','Ộ':'o','ộ':'o','Ɵ':'o','ɵ':'o','Ṕ':'p','ṕ':'p','Ṗ':'p','ṗ':'p','Ᵽ':'p','Ƥ':'p','ƥ':'p','P':'p','̃':'p','p':'p','̃':'p','ʠ':'q','Ɋ':'q','ɋ':'q','Ŕ':'r','ŕ':'r','Ř':'r','ř':'r','Ṙ':'r','ṙ':'r','Ŗ':'r','ŗ':'r','Ȑ':'r','ȑ':'r','Ȓ':'r','ȓ':'r','Ṛ':'r','ṛ':'r','Ṝ':'r','ṝ':'r','Ṟ':'r','ṟ':'r','Ɍ':'r','ɍ':'r','ᵲ':'r','ɼ':'r','Ɽ':'r','ɽ':'r','ɾ':'r','ᵳ':'r','ß':'s','Ś':'s','ś':'s','Ṥ':'s','ṥ':'s','Ŝ':'s','ŝ':'s','Š':'s','š':'s','Ṧ':'s','ṧ':'s','Ṡ':'s','ṡ':'s','ẛ':'s','Ş':'s','ş':'s','Ṣ':'s','ṣ':'s','Ṩ':'s','ṩ':'s','Ș':'s','ș':'s','ʂ':'s','S':'s','̩':'s','s':'s','̩':'s','Þ':'t','þ':'t','Ť':'t','ť':'t','T':'t','̈':'t','ẗ':'t','Ṫ':'t','ṫ':'t','Ţ':'t','ţ':'t','Ṭ':'t','ṭ':'t','Ț':'t','ț':'t','Ṱ':'t','ṱ':'t','Ṯ':'t','ṯ':'t','Ŧ':'t','ŧ':'t','Ⱦ':'t','ⱦ':'t','ᵵ':'t','ƫ':'t','Ƭ':'t','ƭ':'t','Ʈ':'t','ʈ':'t','ȶ':'t','Ú':'u','ú':'u','Ù':'u','ù':'u','Ŭ':'u','ŭ':'u','Û':'u','û':'u','Ǔ':'u','ǔ':'u','Ů':'u','ů':'u','Ü':'u','ü':'u','Ǘ':'u','ǘ':'u','Ǜ':'u','ǜ':'u','Ǚ':'u','ǚ':'u','Ǖ':'u','ǖ':'u','Ű':'u','ű':'u','Ũ':'u','ũ':'u','Ṹ':'u','ṹ':'u','Ų':'u','ų':'u','Ū':'u','ū':'u','Ṻ':'u','ṻ':'u','Ủ':'u','ủ':'u','Ȕ':'u','ȕ':'u','Ȗ':'u','ȗ':'u','Ư':'u','ư':'u','Ứ':'u','ứ':'u','Ừ':'u','ừ':'u','Ữ':'u','ữ':'u','Ử':'u','ử':'u','Ự':'u','ự':'u','Ụ':'u','ụ':'u','Ṳ':'u','ṳ':'u','Ṷ':'u','ṷ':'u','Ṵ':'u','ṵ':'u','Ʉ':'u','ʉ':'u','Ṽ':'v','ṽ':'v','Ṿ':'v','ṿ':'v','Ʋ':'v','ʋ':'v','Ẃ':'w','ẃ':'w','Ẁ':'w','ẁ':'w','Ŵ':'w','ŵ':'w','W':'w','̊':'w','ẘ':'w','Ẅ':'w','ẅ':'w','Ẇ':'w','ẇ':'w','Ẉ':'w','ẉ':'w','Ẍ':'x','ẍ':'x','Ẋ':'x','ẋ':'x','Ý':'y','ý':'y','Ỳ':'y','ỳ':'y','Ŷ':'y','ŷ':'y','Y':'y','̊':'y','ẙ':'y','Ÿ':'y','ÿ':'y','Ỹ':'y','ỹ':'y','Ẏ':'y','ẏ':'y','Ȳ':'y','ȳ':'y','Ỷ':'y','ỷ':'y','Ỵ':'y','ỵ':'y','ʏ':'y','Ɏ':'y','ɏ':'y','Ƴ':'y','ƴ':'y','Ź':'z','ź':'z','Ẑ':'z','ẑ':'z','Ž':'z','ž':'z','Ż':'z','ż':'z','Ẓ':'z','ẓ':'z','Ẕ':'z','ẕ':'z','Ƶ':'z','ƶ':'z','Ȥ':'z','ȥ':'z','ʐ':'z','ʑ':'z','Ⱬ':'z','ⱬ':'z','Ǯ':'z','ǯ':'z','ƺ':'z','２':'2','６':'6','Ｂ':'B','Ｆ':'F','Ｊ':'J','Ｎ':'N','Ｒ':'R','Ｖ':'V','Ｚ':'Z','ｂ':'b','ｆ':'f','ｊ':'j','ｎ':'n','ｒ':'r','ｖ':'v','ｚ':'z','１':'1','５':'5','９':'9','Ａ':'A','Ｅ':'E','Ｉ':'I','Ｍ':'M','Ｑ':'Q','Ｕ':'U','Ｙ':'Y','ａ':'a','ｅ':'e','ｉ':'i','ｍ':'m','ｑ':'q','ｕ':'u','ｙ':'y','０':'0','４':'4','８':'8','Ｄ':'D','Ｈ':'H','Ｌ':'L','Ｐ':'P','Ｔ':'T','Ｘ':'X','ｄ':'d','ｈ':'h','ｌ':'l','ｐ':'p','ｔ':'t','ｘ':'x','３':'3','７':'7','Ｃ':'C','Ｇ':'G','Ｋ':'K','Ｏ':'O','Ｓ':'S','Ｗ':'W','ｃ':'c','ｇ':'g','ｋ':'k','ｏ':'o','ｓ':'s','ｗ':'w'
};

function accent_fold (s) {
    if (!s) { return ''; }

    var ret = '';
    for (var i = 0; i < s.length; i++) {
        ret += accent_map[s.charAt(i)] || s.charAt(i);
    }
    return ret;
};

$.fn.dataTableExt.ofnSearch = function (data) {
    return accent_fold(data);
};

I modified your question's original code to use an accent-folding function (available on Github). You might also be interested in the original article from "A List Apart".

Question 6

For future readers,

using accent-neutralise only solves part of the problem of searching in a case-insensitive way. The plugin only replaces some accented chars to non-accented chars inside the table. You will also need to remove accents from your search textbox input.

Another problem I had is that the plugin only replaces lowercase letters, so I went ahead and added some extra mapping for the most common accented letters in french, based on this other great solution: Remove accents/diacritics in a string in JavaScript

accent-neutralise-french.js

function accents_supr(data){
return !data ?
    '' :
    typeof data === 'string' ?
        data
            .replace(/\n/g, ' ')
            .replace(/[\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]/g, 'a')
            .replace(/[\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]/g, 'e')
            .replace(/[\u0069\u24D8\uFF49\u00EC\u00ED\u00EE\u0129\u012B\u012D\u00EF\u1E2F\u1EC9\u01D0\u0209\u020B\u1ECB\u012F\u1E2D\u0268\u0131]/g, 'i')
            .replace(/[\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]/g, 'o')
            .replace(/[\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]/g, 'u')
            .replace(/[\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]/g, 'A')
            .replace(/[\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]/g, 'E')
            .replace(/[\u0049\u24BE\uFF29\u00CC\u00CD\u00CE\u0128\u012A\u012C\u0130\u00CF\u1E2E\u1EC8\u01CF\u0208\u020A\u1ECA\u012E\u1E2C\u0197]/g, 'I')
            .replace(/[\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]/g, 'O')
            .replace(/[\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]/g, 'U')
            .replace(/ç/g, 'c')
            .replace(/Ç/g, 'C') :
        data;
};

jQuery.fn.DataTable.ext.type.search['string'] = function(data) {
    return accents_supr(data);
};

In your page with a dataTable :

 // Remove accented character from search input as well
    $('#dt_basic_filter input[type=search]').keyup( function () {
        var table = $('#dt_basic').DataTable(); 
        table.search(
            jQuery.fn.DataTable.ext.type.search.string(this.value)
        ).draw();
    } );

Question 7

Additional feedback on column filtering : the comments above will only work if the column to filter is of type "string" (the DataTables column type defined here).

If the column contains HTML tags, the DataTables lib will automagically tag it as "html" type, and it will trigger the associated search callback on that type. Therefore for the filtering to apply properly, the callback needs to be registered on the "html" type :

$.fn.DataTable.ext.type.search['html'] = function(data) {
  return unaccent(data);
};

where unaccent is a function that removes accents / diacritics / strange characters from the input string.

Question 8

My question is the same about searching without accent but finding answers with accent like search with cafe and display results with café

I don't use a table but div and I don't have the clue to adapt the solutions to my site.

Here is my code for searching

    $(document).ready(function(){
  $("#myInput").on("keyup", function() {
    var value = $(this).val().toLowerCase();
    $("#myDIV div").filter(function() {
      $(this).toggle($(this).text().toLowerCase().indexOf(value) > -1)
    });
  });
});

Thank you for your help

jQuery DataTables - Accent-Insensitive Alphabetization and Searching

EDIT