making a list variable optional instead of required

**Tullamore** · 04-20-2012, 04:06 PM

I'm working with this application:
http://www.grabilla.com/02414-a3219a...fbb0a9c9ae.png

I have the Notes field on the invoice implemented, but I want it to be an optional field. Right now I can't submit anything with the notes field empty. Here is my code, there are 2 seperate .js files for this, the library.js and the main.js:

library:

HTML Code:

String.prototype.pad_left = function() {
    if ( arguments.length < 1 || arguments.length > 2 ) {
        return this;
    }
    var width = parseInt(arguments[0]);
    var pad = " ";
    if ( arguments.length == 2 ) pad = arguments[1];
    
    var result = this;
    while ( result.length < width ) {
        result = pad + result;
    }
    return result;
}

String.prototype.pad_right = function() {
    if ( arguments.length < 1 || arguments.length > 2 ) {
        return this;
    }
    var width = parseInt(arguments[0]);
    var pad = " ";
    if ( arguments.length == 2 ) pad = arguments[1];
    
    var result = this;
    while ( result.length < width ) {
        result = result + pad;
    }
    return result;
}

var Item_Info = function( item_name, item_cost, item_qty, item_notes ) {
    this.item_name = item_name;
    this.item_cost = parseFloat(item_cost);
    this.item_qty  = parseInt(item_qty);
    this.item_notes = item_notes;
}

var Invoice = function() {
    this.items = [];
    this.tax_rate = 0.07;
}

Invoice.prototype.add_item = function(item_code, item_info) {
    if ( ! item_info instanceof Item_Info ) return this;
    if ( isNaN(item_info.item_cost) ) return this;
    if ( isNaN(item_info.item_qty)  ) return this;
    if ( item_info.item_name == ""  ) return this;
    if ( item_code == "" ) return this;
    if ( item_info.item_notes == "") return this;
    
    item_code = item_code.toUpperCase();
    if ( item_code in this.items ) {
        delete this.items[item_code];
    }
    
    this.items[item_code] = item_info;
    this.sort_by_code();
    
    return this;
}

Invoice.prototype.delete_item = function(item_code) {
    item_code = item_code.toUpperCase();
    if ( item_code in this.items ) {
        delete this.items[item_code];
    }
    return this;
}

Invoice.prototype.get_item_list = function() {
    var item_list, line_cost, item_count, item_notes = 0;
    item_list  = "Item Code".pad_right(10) + " ";
    item_list += "Item Name".pad_right(25) + " ";
    item_list += "Qty ";
    item_list += "Item Cost ";
    item_list += "Line Cost ";
    item_list += "Notes\n";
    item_list += "".pad_right(10,"-") + " ";
    item_list += "".pad_right(25,"-") + " ";
    item_list += "--- ";
    item_list += "".pad_right(9,"-") + " ";
    item_list += "".pad_right(9,"-") + " ";
    item_list += "".pad_right(25,"-") + " "; 
    for ( var code in this.items ) {
        line_cost =
            this.items[code].item_qty * this.items[code].item_cost;
        item_list += code.pad_right(10) + " ";
        item_list += this.items[code].item_name.pad_right(25) + " ";
        item_list += 
            this.items[code].item_qty.toString().pad_left(3) + " ";
        item_list +=
            "$" + this.items[code].item_cost.toFixed(2).pad_left(8) + " ";
        item_list += "$" + line_cost.toFixed(2).pad_left(8) + " ";
        item_list += this.items[code].item_notes.pad_right(25) + "\n";
        item_count++;
    }
    return (item_count == 0) ? "" : item_list;
}

Invoice.prototype.get_subtotal = function () {
    var subtotal = 0, line_cost;
    for ( var code in this.items ) {
        line_cost =
            this.items[code].item_qty * this.items[code].item_cost;
        subtotal += parseFloat( line_cost.toFixed(2) );
    }
    return subtotal;
}

Invoice.prototype.get_sales_tax = function () {
     var subtotal = this.get_subtotal();
     var sales_tax = subtotal * this.tax_rate;
     return parseFloat( sales_tax.toFixed(2) );
}

Invoice.prototype.get_total = function () {
    var total = this.get_subtotal() + this.get_sales_tax();
    return parseFloat( total.toFixed(2) );
}

Invoice.prototype.sort_by_code = function () {
    var code, codes = [], sorted_list = [];
    for ( code in this.items ) codes.push(code);
    codes.sort();
    for ( code in codes ) {
        sorted_list[ codes[code] ] = this.items[ codes[code] ];
    }
    this.items = sorted_list;
    return this;
}

main:

Code:

var invoice = new Invoice();

var $ = function(id) { return document.getElementById(id); }

var update_invoice = function () {
    $("item_list").value = invoice.get_item_list();
    $("subtotal").value = invoice.get_subtotal().toFixed(2);
    $("sales_tax").value = invoice.get_sales_tax().toFixed(2);
    $("total").value = invoice.get_total().toFixed(2);

    $("item_code").value = "";
    $("item_name").value = "";
    $("item_cost").value = "";
    $("item_qty").value = "1";
    $("item_notes").value = "";
    $("item_delete_code").value = "";

    $("item_code").focus();
}    

var item_add_click = function() {
    var item_code = $("item_code").value;
    var item_name = $("item_name").value;
    var item_cost = $("item_cost").value;
    var item_qty  = $("item_qty").value;
    var item_notes = $("item_notes").value;
    var item_info = new Item_Info(item_name, item_cost, item_qty, item_notes);
    
    invoice.add_item(item_code, item_info);
    update_invoice();
}

var item_delete_click = function() {
    var item_code = $("item_delete_code").value;
    invoice.delete_item(item_code);
    update_invoice();
}

window.onload = function () {
    $("item_add").onclick = item_add_click;
    $("item_delete").onclick = item_delete_click;
	update_invoice();
    $("item_code").focus();
}

I had to wrap the first block in HTML tags because the regular code tags didn't work for some reason, and, as always, any help is much appreciated.