Chapter 13

Antonius Block · January 7th, 2014, 04:50 PM

Hello Imar,

in the Genre GridView (chapter 13) I added the following property to the Delete button (which I had converted from a CommandField to an ItemTemplate):

Code:

OnClientClick="return confirm('Do you really want to delete the selected genre ?');"

in order to prevent unintentional deletes.

It works, but I would like to refine it.
I would like to concatenate the name of the genre selected so that the message to the user turns, for instance, into:
'Do you really want to delete the Hard Rock genre ?'

I'm trying to do that by means of a Javascript function, but I got an error at

Code:

document.getElementById('<%= labelGenreName.ClientId%>')

Therefore I cannot reach the Label whose value is the name of the genre.
By the way, the label is into an ItemTemplate, as I converted the original BoundField into a Template.

Can you tell me how to concatenate the name of the genre into the message ?

Thank you

Imar · January 7th, 2014, 05:14 PM

Hi Antonius,

One way to do it is using databinding:

Code:

OnClientClick=<%# String.Format("return confirm('Do you really want to delete the {0} genre?');", Eval("Name")) %>

Notice that the entire data binding expression doesn't use quotes. If you'd use single or double quotes, the strings in the expression would break the tag.

This is a bit messy, so you could also do it from Code Behind as explained here: http://stackoverflow.com/a/102479/1498619

With you solution, you run into issues, as each label for each row will have a unique ID. Take a look at the HTML in the browser to see what I mean. You could pass the name to the function to make things a lot easier:

Code:

OnClientClick=<%# String.Format("confirmDelete('{0}');", Eval("Name")) %>

where confirmDelete is your custom confirmation function that accepts the genre name.

Finally, you could also use jQuery to do all this dynamically. You could find sibling table cells that contain the genre name to create the proper prompt.

Hope this helps,

Imar