SF_10.1, SF_10.2, SF_11.0, SF_11.1, SF_11.2, SF_12.0, SF_12.1, SF_12.2, SF_13.0, SF_13.1, SF_13.2, SF_13.3 - https://docs.sitefinity.com/devreach-site-create-the-widget-template

DevReach_CreateWidgetTmplate.ascx

<%@ Control Language="C#" AutoEventWireup="true" CodeBehind="MySessions.ascx.cs" Inherits="SitefinityWebApp.MySessions" %>
 <%@ Import Namespace="System.Data.Common" %>
 <%@ Import Namespace="System.Data" %>
 <%@ Import Namespace="Telerik.Sitefinity.RelatedData" %>
  
 <table class="list-sessions">
     <asp:Repeater runat="server" ID="SessionsRepeater">
         <ItemTemplate>
             <tr>
                 <td>
                     <h3>
                         <%# Eval("Title")%>
                         <span>
                             <asp:Repeater runat="server" ID="speakers" DataSource='<%# Eval("Speakers")%>'>
                                 <ItemTemplate>
                                     <%# Eval("Title") %>, 
                                 </ItemTemplate>
                             </asp:Repeater>
                         </span>
                     </h3>
                 </td>
                 <td><%# Eval("Location.Title")%></td>
                 <td class="attended">Attended by <span runat="server"><%# Eval("CurrentAttendees")%></span></td>
                 <td>
                     <asp:Button ID="click" class='<%# CheckIsAttended(Container.DataItem)?"small positive":"small negative" %>' runat="server"
                         Text='<%# CheckIsAttended(Container.DataItem)?"Attending":"Will Attend" %>'
                         CommandName='<%# CheckIsAttended(Container.DataItem)?"NotAttend":"Attend" %>'
                         OnCommand="CommandBtn_Click"
                         CommandArgument='<%# Eval("OriginalContentId") %>' />
                 <td>
             </tr>
         </ItemTemplate>
     </asp:Repeater>
 </table>