word-preserving truncate

gistfile1.js

splitBody: function(body, max_chars){
    var truncate_pos = max_chars - 1;
    var word_char = XRegExp("\\p{L}");
    if (body.length > max_chars){
        if (word_char.test(body.charAt(truncate_pos))){
            var next = (body.length > max_chars + 1) ? body.charAt(max_chars) : '';
            if (next && word_char.test(next)){
                // Roll back the truncate position to the nearest word boundary.
                for (var i = truncate_pos; i > 0 && word_char.test(body.charAt(i)); i--);
                (i > 0) && (truncate_pos = i);
            }
        }
        return [body.substr(0, truncate_pos + 1), body.substr(truncate_pos + 1)];
    }
    return [body, ''];
}