Valuta automatisch opmaken met JQuery

Valuta-invoerveld automatisch opmaken met komma's en decimalen indien nodig. Tekst wordt automatisch opgemaakt met komma's en de cursor wordt teruggeplaatst waar de gebruiker was gebleven na het formatteren versus de cursor die naar het einde van de invoer gaat. Validatie vindt plaats op KeyUp en een laatste validatie vindt plaats op vervaging.

HTML

<input type="text" class="currency">

javascript

$(".currency").on({  
    keyup: function() {  
        let input_val = $(this).val();  
        input_val = numberToCurrency(input_val);  
        $(this).val(input_val);  
    },  
    blur: function() {   
        let input_val = $(this).val();  
        input_val = numberToCurrency(input_val, true, true);  
        $(this).val(input_val);  
    }  
});  
  
var numberToCurrency = function(input_val, fixed = false, blur = false) {  
    // don't validate empty input  
    if(!input_val) {  
        return "";  
    }  
      
    if(blur) {  
        if(input_val === "" || input_val == 0) { return 0; }  
    }  
  
    if(input_val.length == 1) {  
        return parseInt(input_val);  
    }  
  
    input_val = ''+input_val;  
      
    let negative = '';  
    if(input_val.substr(0, 1) == '-'){  
        negative = '-';  
    }  
    // check for decimal  
    if(input_val.indexOf(".") >= 0) {  
        // get position of first decimal  
        // this prevents multiple decimals from  
        // being entered  
        var decimal_pos = input_val.indexOf(".");  
  
        // split number by decimal point  
        var left_side = input_val.substring(0, decimal_pos);  
        var right_side = input_val.substring(decimal_pos);  
  
        // add commas to left side of number  
        left_side = left_side.replace(/\D/g, "").replace(/\B(?=(\d{3})+(?!\d))/g, ",");  
  
        if(fixed && right_side.length > 3) {  
            right_side = parseFloat(0+right_side).toFixed(2);  
            right_side =  right_side.substr(1, right_side.length);  
        }  
  
        // validate right side  
        right_side = right_side.replace(/\D/g, "").replace(/\B(?=(\d{3})+(?!\d))/g, ",");  
  
        // Limit decimal to only 2 digits  
        if(right_side.length > 2) {  
            right_side = right_side.substring(0, 2);  
        }  
      
        if(blur && parseInt(right_side) == 0) {  
            right_side = '';  
        }  
  
        // join number by.  
        // input_val = left_side + "." + right_side;  
  
        if(blur && right_side.length < 1) {  
            input_val = left_side;  
        } else {  
            input_val = left_side + "." + right_side;  
        }  
    } else {  
        // no decimal entered  
        // add commas to number  
        // remove all non-digits  
        input_val = input_val.replace(/\D/g, "").replace(/\B(?=(\d{3})+(?!\d))/g, ",");  
    }  
  
    if(input_val.length > 1 && input_val.substr(0, 1) == '0' && input_val.substr(0, 2) != '0.') {  
        input_val = input_val.substr(1, input_val.length);  
    } else if(input_val.substr(0, 2) == '0,') {  
        input_val = input_val.substr(2, input_val.length);  
    }  
      
    return negative+input_val;  
};