воскресенье, 30 августа 2009 г.

Avoid Multiple Form Submits

Multiple form submits can result difficulties in web applications because of unexpected behaviors like multiple entries in database. Here is a solution to help you avoid multiple submits.


If you are submitting the page only once then you can use,

<form onsubmit="return Submit();">
And the method is like,
<script type="text/javascript">
var flag = false;

function Submit()
{
if (flag)
{
return false;
}
else
{
flag = true;
return true;
}
}
<
/script>


For a single button you can use,
btnSubmit.Attributes["onclick"] = "this.disabled=true;" +
GetPostBackEventReference(btnSubmit);
For pages with update panels multiple submit is a real problem as page is posting asynchronously or partially.In that scenario you can use Sys.WebForms.PageRequestManager for fixing the issue,
<asp:ScriptManager ID="ScriptManager1" runat="server">
</asp:ScriptManager>

<script type="text/javascript">

Sys.WebForms.PageRequestManager.getInstance().add_beginRequest(BeginRequest);

function BeginRequest(sender, e)
{
e.get_postBackElement().disabled = true;
}

</script>

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