asp.net Do not validate Modal form when hidden - asp.net

Question

I have a modal form (bootstrap), I am using asp.net RequiredFieldValidtors for data entry validation. This validation should only fire when the modal is visible and the user is entering new values into the modal.
The problem I am having is that the validation triggers when the model form is not shown preventing my main page from accepting new data entry from. My modal is only used to add new values and is not part of the normal workflow on my main page.
I have been stuck on this for two days now and have tried many different things and just can't get it figured out.
Any suggestions on how to handle this while keeping my RequiredFieldValidator rules intact?
Thanks
Edit - Adding modal forms code.
<asp:UpdatePanel ID="UpdatePanel2" runat="server" UpdateMode="Conditional" ChildrenAsTriggers="true">
<ContentTemplate>
<div class="modal fade" id="modNewStakeholder" tabindex="-1" role="dialog" aria-labelledby="myModalLabel" aria-hidden="true">
<div class="modal-dialog modal-sm">
<div class="modal-content">
<div class="modal-header">
<button type="button" class="close" data-dismiss="modal"><span aria-hidden="true">×</span><span class="sr-only">Close</span></button>
<h4 class="modal-title">Add Stakeholder</h4>
</div>
<div class="modal-body">
<div class="form-group">
<label class="control-label">First Name:</label>
<asp:TextBox class="form-control focus" ID="tFirstName" runat="server" AutoComplete="off" placeholder="First name is required"></asp:TextBox>
<asp:RequiredFieldValidator ID="rftFirstName"
runat="server" ErrorMessage="Required Field"
ControlToValidate="tFirstName" Display="Dynamic"
ValidationGroup="ValGroupNewStake"></asp:RequiredFieldValidator>
</div>
<div class="form-group">
<label class="control-label">Last Name:</label>
<asp:TextBox class="form-control" ID="tLastName" runat="server" AutoComplete="off" placeholder="Last name is required"></asp:TextBox>
<asp:RequiredFieldValidator ID="rftLastName"
runat="server" ErrorMessage="Required Field" ControlToValidate="tLastName" Display="Dynamic"
ValidationGroup="ValGroupNewStake"></asp:RequiredFieldValidator>
</div>
<div class="form-group">
<label class="control-label">E-Mail:</label>
<asp:TextBox class="form-control" ID="tEmail" runat="server" AutoComplete="off" placeholder="Email must contain #expeditors.com"></asp:TextBox>
<asp:RequiredFieldValidator ID="rftEmail" runat="server" ControlToValidate="tEmail" Display="Dynamic"
ValidationGroup="ValGroupNewStake"
ErrorMessage="Required Field">
</asp:RequiredFieldValidator>
<asp:RegularExpressionValidator ID="rftEmailAt" runat="server" ControlToValidate="tEmail" Display="Dynamic"
ErrorMessage="Invalid Email, must contain #"
ValidationGroup="ValGroupNewStake"
ValidationExpression="^\w+[\w-\.]*\#\w+((-\w+)|(\w*))\.[a-z]{2,3}$">
</asp:RegularExpressionValidator>
<asp:RegularExpressionValidator ID="rftEmailDomaain" runat="server" ControlToValidate="tEmail" Display="Dynamic"
ErrorMessage="Invalid Email, must be an #abc.com domain"
ValidationGroup="ValGroupNewStake"
ValidationExpression="^.+#[Aa][Bb][Cc][.][Cc][Oo][Mm]$">
</asp:RegularExpressionValidator>
</div>
</div>
<div class="modal-footer">
<div class="btn-group" role="group" aria-label="...">
<button type="button" class="btn btn-success btn-sm" id="cmdOk_AddSholder" runat="server" onserverclick="cmdOk_AddSholder_ServerClick" ValidationGroup="ValGroupNewStake" causesvalidation="false">Ok</button>
<button type="button" class="btn btn-danger btn-sm" id="cmdCancel_AddSholder" runat="server" data-dismiss="modal" onserverclick="cmdCancel_AddSholder_ServerClick">Cancel</button>
</div>
</div>
</div>
</div>
</div>
</ContentTemplate>
<Triggers>
<asp:AsyncPostBackTrigger ControlID="cmdOk_AddSholder" EventName="serverclick" />
</Triggers>
</asp:UpdatePanel>

Answer 1

I've put together a very simplified example of how my application is doing this. The Modal is just an ascx control and does not have an updatepanel. It's actually just a control becoming visible but we use CSS and JavaScript to make it a modal. The same logic should still apply as I've made this sample from a functioning modal.
Modal.ascx
Validators have ValidationGroup and are disabled. Button is also assigned to ValidationGroup:
<div id="approvalModal" style="display: none;">
<asp:TextBox ID="TextBox1" runat="server"></asp:TextBox>
<asp:RequiredFieldValidator ID="RequiredFieldValidator1" runat="server" Enabled="false"
ControlToValidate="TextBox1" ValidationGroup="testValidationgGroup" ErrorMessage="RequiredFieldValidator"></asp:RequiredFieldValidator>
<asp:Button ID="Button1" runat="server" Text="Button" ValidationGroup="testValidationgGroup" />
</div>
Modal.ascx.vb
Enable the validator in a property:
Partial Class Modal
Inherits System.Web.UI.UserControl
Public WriteOnly Property Enable() As Boolean
Set(value As Boolean)
RequiredFieldValidator1.Enabled = value
End Set
End Property
End Class
PageWithModal.aspx (note: uses jQuery)
<script>
function setupTestModal() {
var modal = $('#approvalModal');
if (modal.css('display') == 'none') {
modal.show();
}
}
</script>
<asp:Button ID="ShowModal" runat="server" Text="Show Modal" OnClick="ShowModal_Click" />
<uc1:Modal runat="server" ID="testModal" />
PageWithModal.aspx.vb
Notice that when you click the ShowModal button, the validation does NOT fire. However, when the modal is visible, the Validator has been enabled.
Protected Sub ShowModal_Click(sender As Object, e As EventArgs)
testModal.Enable = True
Dim script = String.Concat("setupTestModal();")
ScriptManager.RegisterStartupScript(Me.Page, Me.Page.GetType(), "Popup", script, True)
End Sub