Javascript handling of combining diacritic characters

diacritic.js

// TODO: complete the mapping
var combiningDiacriticMap = {
	// combining grave accent
	'\u0300': {
		'A': '\u00c0', 'a': '\u00e0',
		'E': '\u00c8', 'e': '\u00e8',
		'I': '\u00cc', 'i': '\u00ec',
		'O': '\u00d2', 'o': '\u00f2',
		'U': '\u00d9', 'u': '\u00f9'
	},
	// combining acute accent
	'\u0301': {
		'A': '\u00c1', 'a': '\u00e1',
		'E': '\u00c9', 'e': '\u00e9',
		'I': '\u00cd', 'i': '\u00ed',
		'O': '\u00d3', 'o': '\u00f3',
		'U': '\u00da', 'u': '\u00fa',
		'Y': '\u00dd', 'y': '\u00fd',
		'C': '\u0106', 'c': '\u0107'
	},
	// combining circumflex accent
	'\u0302': {
		'A': '\u00c2', 'a': '\u00e2',
		'E': '\u00ca', 'e': '\u00ea',
		'I': '\u00ce', 'i': '\u00ee',
		'O': '\u00d4', 'o': '\u00f4',
		'U': '\u00db', 'u': '\u00fb',
		'C': '\u0108', 'c': '\u0109',
		'J': '\u0134', 'j': '\u0135'
	},
	// combining tilde
	'\u0303': {
		'A': '\u00c3', 'a': '\u00e3',
		'O': '\u00d5', 'o': '\u00f5',
		'I': '\u0128', 'i': '\u0129',
		'U': '\u0168', 'u': '\u0169'
	},
	// combining macron
	// '\u0304': {
	// },
	// combining overline
	// '\u0305': {
	// },
	// combining breve
	// '\u0306': {
	// },
	// combining dot above
	// '\u0307': {
	// },
	// combining diaresis
	'\u0308': {
		'A': '\u00c4', 'a': '\u00e4',
		'E': '\u00cb', 'e': '\u00eb',
		'I': '\u00cf', 'i': '\u00ef',
		'O': '\u00d6', 'o': '\u00f6',
		'U': '\u00dc', 'u': '\u00fc',
		'Y': '\u0178', 'y': '\u00ff'
	},
	// combining hook above
	// '\u0309': {
	// },
	// combining ring above
	'\u030a': {
		'A': '\u00c5',
		'U': '\u016e', 'u': '\u016f'
	},
	// combining double acute accent
	'\u030b': {
		'O': '\u0150', 'o': '\u0151',
		'U': '\u0170', 'u': '\u0171'
	},
	// combining caron
	'\u030c': {
		'C': '\u010c', 'c': '\u010d',
		'D': '\u010e', 'd': '\u010f',
		'E': '\u011a', 'e': '\u011b',
		'L': '\u013d', 'l': '\u013e',
		'N': '\u0147', 'n': '\u0148',
		'S': '\u0160', 's': '\u0161',
		'T': '\u0164', 't': '\u0165',
		'Z': '\u017d', 'z': '\u017e'
	},
	// combining vertical line above
	// '\u030d': {
	// },
	// combining double vertical line above
	// '\u030e': {
	// },
	// combining double grave accent
	// '\u030f': {
	// },
	// combining candrabindu
	// '\u0310': {
	// },
	// combining inverted breve
	// '\u0311': {
	// },
	// combining turned comma above
	// '\u0312': {
	// },
	// combining comma above
	// '\u0313': {
	// },
	// combining reversed comma above
	// '\u0314': {
	// },
	// combining comma above right
	// '\u0315': {
	// },
	// combining grave accent below
	// '\u0316': {
	// },
	// combining grave accent below
	'\u0328': {
		'A': '\u0104', 'a': '\u0105',
		'E': '\u0118', 'e': '\u0119',
		'I': '\u012e', 'i': '\u012f',
		'U': '\u0172', 'u': '\u0173'
	},
	// combining short stroke overlay
	'\u0335': {
		'L': '\u0141', 'l': '\u0142'
	},
	// combining long stroke overlay
	'\u0336': {
		'L': '\u0141', 'l': '\u0142'
	},
	// combining short solidus overlay
	'\u0337': {
		'L': '\u0141', 'l': '\u0142',
		'O': '\u00d8', 'o': '\u00f8'
	},
	// combining long solidus overlay
	'\u0338': {
		'L': '\u0141', 'l': '\u0142',
		'O': '\u00d8', 'o': '\u00f8'
	}
}

function convertCombiningDiacritic(chr, diacritic) {
	var map = combiningDiacriticMap[diacritic] || {},
		newChr = map[chr];
	return newChr || chr;
}

/**
 * Converts (char, combining diacritic) couple to single diacritic entity.
 * To do so, it iterates over the given string char by char and when it finds
 * a combining diacritic character, it replaces it with the combined entity.
 * If there is no combined entity, the comining diacritic character is dropped.
 */
function convertCombiningDiacritics(str) {
	if (!str.length) return str;
	// append a guard value for simpler handling
	var _str = str + '.';
	var p, c = _str[0];
	var chars = [];
	for (var i=1, ii=_str.length; i < ii; i++) {
		p = c;
		c = _str.charAt(i);
		if (c > '\u0300' && c < '\u036f') {
			chars.push(convertCombiningDiacritic(p, c));
			// When a a character is combined, go forward to the next char.
			// Next iteration will not fail thanks to the guard value.
			c = _str.charAt(++i);
		} else {
			chars.push(p);
		}
	}
	return chars.join('');
}

In essence, it's trying to do the following python snippet: unicodedata.normalize('NFC', string).
Bottom-line: do it server side.