repeater how to avoid blank html - asp.net

Question

We currently have an application which we have a repeater
<asp:Repeater ID="rptOfficials" runat="server">
<ItemTemplate>
<tr>
<td>
<p class="officials">
<%#Eval("OffPosition") %> <%#Eval("FullName") %>
</p>
<p class="officials">
<%#Eval("Phone") %>
</p>
</td>
</tr>
</ItemTemplate>
</asp:Repeater>
The Phone field is not always supplied, when not there a blank paragraph tag is generated, we're thinking of changing
<p class="officials">
<%#Eval("Phone") %>
</p>
to either:
<p class="officials">
<asp:label id="lblPhone" runat="server"/>
</p>
or:
<p class="officials">
<%#GetPhone("OffId") %>
</p>
and then have either the label return the phone number with the paragraph tags wrapped around it, or have the function return it. Is there a better way to get around this?

Answer 1

It depends how your Binding model is composed but I suggest adding the logic in your property (Phone) on your page your (view)model (yes you can and should use ViewModels in web forms as well).
That way you keep logic outside the view.
public string Phone {
get {
return this.phone ?? string.Empty;
}
}
That way your logic stays nicely inside your view model and your view just takes care of binding it.
If you don't want to generate the -tag, you can add a boolean property to your model.
public bool DisplayPhone{
get {
return this.Phone == string.Empty;
}
}
You then need to bind it to the visible property as Halcyon mentioned. (note you need a runat="server" for this)
<p runat="server" class="officials" visible='<% #Eval("DisplayPhone") %>'>
<% #Eval("Phone") %>
</p>

Answer 2

I would not recommend using "display: none" since it will keep the space of the p tag. Instead, make the p tag a server tag and set its visibility to false.
<p runat="server" class="officials" visible='<% !string.IsNullOrEmpty(#Eval("Phone")) %>'>
<% #Eval("Phone") %>
</p>

Answer 3

Instead of using
<p class="officials">
<%#GetPhone("OffId") %>
</p>
I prefer generate <p class="officials">foo</p> inside GetPhone(), then you can return nothing when Phone is empty.

Answer 4

You can add small logic like the following -
<%# string.IsNullOrWhiteSpace(Eval("Phone").ToString()) ?
"" : ("<p class=\"officials\">" + Eval("Phone") + "</p>")%>
However, if you want to add more logic, I would like to suggest to use Repeater.ItemDataBound Event

Answer 5

try with this
<p class="officials" <%#string.IsNullOrEmpty(Eval("Phone").ToString())? "style='display:none;':''" %> >
<%#Eval("Phone") %>
</p>