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skaleem1Flag for Canada

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Calling a Javascript function from codebehind button click event

Do you know what could be the reason the following call to javascript alert is not working from the codebehind button click event? Here is the code and debugging even takes me to the line of code in the if block but I do not see the alert prompted:
 
protected void btnAddCurrentPart_Click(object sender, EventArgs e)
{
if (!blnCurrentPartCompatible)

{


ClientScriptManager script = Page.ClientScript;

if (!script.IsClientScriptBlockRegistered(this.GetType(), "Alert"))

{

 script.RegisterClientScriptBlock(this.GetType(), "Alert", "<script type=text/javascript>alert('Hello there')</script>");

}


return;

}

}

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Avatar of Mlanda T
Mlanda T
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I believe this only needs 1 argument, the script key: IsClientScriptBlockRegistered("Alert")
I see it also accepts 2, never mind.
Avatar of skaleem1

ASKER

I even changed it to:

ClientScriptManager script = Page.ClientScript;

                if (!script.IsClientScriptBlockRegistered("Alert"))
                {

                    script.RegisterClientScriptBlock(this.GetType(), "Alert", "<script type=text/javascript>alert('Hello there')</script>");

                }

but still does not work. Please see that it is being called from a button click event. Is it an issue?
I even tried it on the OnClientClick event but still does not work:

<asp:Button ID="btnAddCurrentPart" runat="server" Text="Add Current Part" Enabled="false" OnClientClick="javascript:CheckCompatibility(); return false;" OnClick="btnAddCurrentPart_Click" />

function CheckCompatibility(CheckCompatibilityForCurrentPartInPortFolio) //
{
                       
            alert(CheckCompatibilityForCurrentPartInPortFolio);

}
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HainKurt,

I know that it works when I place this in the Page_onload event, however I have a logic in the button click event and I only want this to fire when the logic is not true, the complete code is as follows:

protected void btnAddCurrentPart_Click(object sender, EventArgs e)
        {
            RetrieveDataGateway rdg = new RetrieveDataGateway();

           
            bool blnCurrentPartCompatible = false;
            blnCurrentPartCompatible = isCurrentPartCompatibleWithPortfolio();
            if (!blnCurrentPartCompatible)
            {
               
                ClientScriptManager script = Page.ClientScript;

                if (!script.IsClientScriptBlockRegistered(this.GetType(), "Alert"))
                {

                    script.RegisterClientScriptBlock(this.GetType(), "Alert", "<script type=text/javascript>alert('Hello there')</script>");

                }

               
                return;
            }
            else
            {
                //Do whatever you want to process
            }
        }
If you put a breakpoint... does that condition [isCurrentPartCompatibleWithPortfolio()] ever evaluate to 'false'... which would make the if work...

It certainly does not look like the problem is coming from the javascript.
Yes it does and it even steps into the if block and through the line of code that triggers the javascript without any error...
Strange... does the javascript get emitted to the browser at all? If you View Source for the page... do you see the javascript: alert('Hello there')

Try changing this line:

     script.RegisterClientScriptBlock(this.GetType(), "Alert", "<script type=text/javascript>alert('Hello there')</script>");

TO:

     script.RegisterClientScriptBlock(this.GetType(), "Alert", "alert('Hello there');", true);
Avatar of urir10
urir10

can you also try this:

 ScriptManager.RegisterClientScriptBlock(btnSubmit, typeof(Button), "Saved", "alert('Hello there');", true);
if you do this

response.write("<script type=text/javascript>alert('Hello there')</script>");

what happens ;)
Thanks for all your help however the reason was something entirely different which I found out after extensive debugging and reviewing the html view. Long story short, the button btnAddCurrentPart is part of an ajaz based update panel that was causing not to fire the client side script before the postback. What I did was to force a postback in the page load event, something like this:

btnAddCurrentPart.OnClientClick = String.Format("fnClickOK('{0}','{1}','{2}','{3}','{4}')", btnAddCurrentPart.UniqueID, "", "AddCurrentPart", _User, "");

In the fnClickOK function, I do all my client side validation before forcing a postback so that my button click event code behind executes:

 function fnClickOK(sender, e, Flag, UserLogin, IsPrivate)
       {
//Do my client side validation here:
__doPostBack(sender,e);
}

and that solved the problem. The notable thing is how the Update Panel affects the postbacks unless you design the aspx page taking into considerations with all the important options this update panel comes with...

However, because some of you pointed me to the right direction, i.e, checking the html etc., I will split the points between two of you, thanks for your help anyways.
Because you pointed me to the right direction, i.e, checking the html etc., I will split the points between two of you, thanks for your help anyways.