Validation Before Postback Event on Masterpage Asp.net - asp.net

Question

I was wondering if anyone knew of a way to do some client side validation with jquery and then run the postback event manually for a asp.net control?
Here's a sample Master page
i.e.
<script type="text/javascript">
$(document).ready(function() {
$("#<%=lnkbtnSave.ClientID %>").click(function() {
alert("hello");
// Do some validation
// If validation Passes then post back to lnkbtnSave_Click Server side Event
});
});
</script>
<asp:LinkButton ID="lnkbtnSave" runat="server" onclick="lnkbtnSave_Click" ><asp:Image ID="Image3" runat="server" ImageUrl="~/images/save.gif" AlternateText="Save" />Save</asp:LinkButton>
Master Page Code Behind
public delegate void MasterPageMenuClickHandler(object sender, System.EventArgs e);
public event MasterPageMenuClickHandler MenuButton;
protected void lnkbtnSave_Click(object sender, EventArgs e)
{
// Assign value to public property
_currentButton = "Save";
// Fire event to existing delegates
OnMenuButton(e);
}
protected virtual void OnMenuButton(EventArgs e)
{
if (MenuButton != null)
{
//Invokes the delegates.
MenuButton(this, e);
}
}
Content Page Code behind
protected void Page_Load(object sender, EventArgs e)
{
Master.MenuButton += new Form.MasterPageMenuClickHandler(Master_MenuButton);
}
void Master_MenuButton(object sender, EventArgs e)
{
switch (Master.CurrentButton)
{
case "Save":
Save();
break;
case "New":
Response.Redirect("ContentPage.aspx");
break;
default:
break;
}
}
Also the control lnkbtnSave is in a master page so how would i determine which content page i'm on since each content page will have it's own controls to validate.
Thanks for any help

Answer 1

If you look at it in reverse it could be simplified. Instead of doing validation and then initiating the postback, you could validate and prevent the postback if needed.
$('#<%= lnkbtnSave.ClientID %>').click(function(e) {
if (!validate()) {
e.preventDefault(); //will stop the page from posting back.
}
});
If you really need to initiate the postback (and do it the other way) you could explicitly call the __doPostBack() function that ASP.NET puts on the page for you after doing your validation.
// This does the exact same thing as above, but it explicitly calls __doPostBack
// If you use the above code __doPostBack will be called automatically for you.
$('#<%= lnkbtnSave.ClientID %>').click(function(e) {
if (validate()) {
__doPostBack('<%= lnkbtnSave.ClientID %>','');
}
e.preventDefault();
});
Let me know if any of this needs clarification.

Answer 2

For the first question you should be able to just return true to cause the linkbutton to postback and return false to stop it.
$(document).ready(function() {
$("#<%=lnkbtnSave.ClientID %>").click(function() {
alert("hello");
var isValid = false;
// Do some validation
return isValid;
});
});
For your second question, you could have each page add their own version of the validation script, and have the function in the masterpage use it to determine validity:
Master Page:
$(document).ready(function() {
$("#<%=lnkbtnSave.ClientID %>").click(function() {
return pageIsValid();
});
});
Content Page:
function pageIsValid() {
var isValid = false;
//validation logic
return isValid;
}

Answer 3

You can just use a CustomValidator control and set it's ClientValidationFunction property.