Block an asp:Button OnClick event in C# from the OnClientClick event in JavaScript?

Question

I have an asp:Button on my webpage, and it calls into a JavaScript function and a code-behind method. The latter makes a call to navigate to another page. In the JavaScript function, I'm checking for a condition. If this condition is not met, I want to abort the navigation so that the OnClick method is not called. Is this possible?

<asp:Button OnClick="Button_Click" ID="Action1" OnClientClick="SaveValues()"
    Text="Action1" CssClass="specialButton" runat="server" />

Answer 1

To block OnClick from executing, just return false from OnClientClick :

<asp:Button OnClick="Button_Click" ID="Action1" OnClientClick="return SaveValues();"
    Text="Action1" CssClass="specialButton" runat="server" />

Assuming that SaveValues will also return a boolean whether or not the condition was met.

Answer 2

yes it is possible

function SaveValues()
{
if(//check your codition here)
{
return true;
}
else
{
return false;
}
}

<asp:Button OnClick="Button_Click" ID="Action1" OnClientClick="javascript:return SaveValues();" Text="Action1" CssClass="specialButton" runat="server" />

Answer 3

Returning true or false , according to the success of the JavaScript, should prevent or enable the button to submit. So, instead of just tacking it on at the end of OnClientClick , where you'd have to conditionalise it and immediately make your call look much more ugly, let the method indicate its operational status.