[CLOSED] AjaxEvents and Exception

[Timothy]

Hello,



Would it be possible to throw an exception from an AjaxEvent and capture it on the UI?



For example; if I clicked my button:

<ExtJS:Button ID="btnAddCustomer" runat="server" AutoPostBack="False" Text="Add Customer" SkinID="Default">
<AjaxEvents>
<Click OnEvent="btnAddCustomer_Click" />
</AjaxEvents>
</ExtJS:Button>

And code behind:

protected void btnAddCustomer_Click(object sender, AjaxEventArgs e)
{
throw new Exception("Hello World");
}

Would be similar to how you currently handle exceptions with the GridPanel :)

Cheers,
Timothy

[geoffrey.mcgill]

You have a couple options...

1. Don't return a Message and just handle the Failure. The following sample demonstrates handling the Failure response.

Example

<script runat="server">
    protected void Button1_Click(object sender, AjaxEventArgs e)
    {
        throw new ApplicationException("An Exception was thrown on Button2");
    }
</script>

<ext:Button 
    ID="Button1" 
    runat="server" 
    Text="Throw Exception">
    <AjaxEvents>
        <Click 
            OnEvent="Button1_Click" 
            Failure="!{'Warning', 'An error has occured'}"
            />
    </AjaxEvents>
</ext:Button>

2. Catch the Exception server-side, and return a custom message and parameter.

Example

<script runat="server">
    protected void Button2_Click(object sender, AjaxEventArgs e)
    {
        try
        {
            throw new ApplicationException("An Exception was thrown on Button1");
        }
        catch (ApplicationException ex)
        {
            e.UserParamsResponse["failure"] = ex.Message;
        }
    }
</script>

<ext:Button 
    ID="Button2" 
    runat="server" 
    Text="Handle Exception">
    <AjaxEvents>
        <Click
            OnEvent="Button2_Click"
            Success="function(config, params) {
                    Ext.Msg.alert('Warning', params.userParamsResponse.failure);
                }"
            />
    </AjaxEvents>
</ext:Button>

Hope this helps.

[Timothy]

Awesome! You already thought about it ;)

Those are MUCH appreciated examples!

[Vladimir]

Timothy,

one more information. If request was unsuccessful (for example, unhandled exception on server) and ajax event have no failure handler on client then show window with error description (this window showing automatically and can be controled with ShowWarningOnFailure property)

<script runat="server">
    protected void Button1_Click(object sender, AjaxEventArgs e)
    {
        throw new ApplicationException("An Exception was thrown on Button2");
    }
</script>

<ext:Button 
    ID="Button1" 
    runat="server" 
    Text="Throw Exception">
    <AjaxEvents>
        <Click OnEvent="Button1_Click" />
    </AjaxEvents>
</ext:Button>

Can you confirm that with this code you see a window after the button click?

[Timothy]

Yup I do get them, confirmed thanks vlad :)

Cheers,0
Timothy