Validator throwing error.

Question

I have the following RegularExpressionValidator on one of my pages:

<asp:RegularExpressionValidator ID="RegularExpressionValidator2" runat="server" 
                                        ControlToValidate="InKindTextBox"
                                        ErrorMessage="The value entered for 'Cash' must be in a number format.   Examples: 500.00, 500, $500, $50,000 or $500.00" 
                                        ValidationExpression="(?n:(^\$?(?!0,?\d)\d{1,3}(?=(?<1>,)|(?<1>))(\k<1>\d{3})*(\.\d\d)?)$)" >

But when it tries to validate it throws the error below from one of my dynamic JS pages.

When I run this regex through regex texter it works fine. Am i doing something wrong here?

Answer 1

JavaScript uses a different regexp syntax than .NET. See, for example, this page.

Quote from MSDN's RegularExpressionValidator page:

The regular-expression validation implementation is slightly different on the client than on the server. On the client, JScript regular-expression syntax is used. On the server, System.Text.RegularExpressions.Regex syntax is used. Since JScript regular expression syntax is a subset of System.Text.RegularExpressions.Regex syntax, it is recommended that JScript regular-expression syntax be used in order to yield the same results on both the client and the server.

Update: A thorough comparison of regular expression flavors across many languages including .NET and JavaScript can be found here.

Update 2: Below is a regex that should validate currency input using jScript compliant regex:

                        <asp:RegularExpressionValidator ID="RegularExpressionValidator1" runat="server" 
                                    ControlToValidate="CashTextBox" ValidationGroup="vld_Insert"
                                    ErrorMessage="The value entered for 'Cash' must be in a number format.  Examples: 5000, 5000.00, 5,000 or $5,000.00" 
                                    ValidationExpression="^\s*\$?\s*(?!\d{4,},)(\d|\d{1,3},(?=\d{3})(?!\d{4}))*(\.\d{1,2})?\s*$">

Answer 2

I think your regex is too complicated anyway. I'd use something simpler like

^[1-9]\d*(\.\d*)?$

That says no leading 0, at least one number before the decimal point, and an optional decimal point followed by more numbers.

Edit

^\$?([1-9]\d?\d?((,\d{3})*|(\d{3})*)|0?)(\.\d*)?$

To test it

var r = /^\$?([1-9]\d?\d?((,\d{3})*|(\d{3})*)|0?)(\.\d*)?$/;
var shouldMatch = ["$30,000.00", "30,000.00", "9,000.00", "9000", "1", ".12"];
var shouldntMatch = ["30,000000.00", "1.00c", "19,00.00", "$30,00"];
function test1() {
  for (var i in shouldMatch) {
    if (!r.exec(shouldMatch[i])) {
      alert(shouldMatch[i]);
      return;
    }
  }
}
function test2() {
  for (var i in shouldntMatch) {
    if (r.exec(shouldntMatch[i])) {
      alert(shouldntMatch[i]);
      return;
    }
  }
}
test1();
test2();