Hiding column in table based on role in MVC - asp.net-mvc

Question

In some of my tables in the Index View, some roles can see more of the table than others.
So this means I should hide some columns
I've done this quick and dirty as such:
<% bool codesZichtbaar = Roles.IsUserInRole("Admin") || Roles.IsUserInRole("Algemeen Beheer") || Roles.IsUserInRole("Secretariaat"); %>
<table>
<tr>
<th>
</th>
<th>
Adres
</th>
<th>
Instellingsnr.
</th>
<% if (codesZichtbaar) { %>
<th>
Codes
</th>
<%} %>
<th>
IKON
</th>
<th>
Datum Van-Tot
</th>
<th>
</th>
</tr>
<% foreach (var item in Model) { %>
<tr class="inst<%: item.actieveSchool?"active":"inactive" %>">
<td>
<% Html.RenderPartial("buttons", new MVC2_NASTEST.Models.ButtonDetail() { RouteValues = new { id = item.Inst_ID }, edit = false, details = true, delete = false, takeOptionalsFromUrl = true }); %>
</td>
<td>
<%: item.INST_NAAM%><br />
<%: item.STRAAT%><br />
<%: item.POSTCODE%>
<%: item.GEMEENTE%>
</td>
<td>
<%: item.DOSSNR%>
</td>
<% if (codesZichtbaar) { %>
<td>
Gebruiker:
<%: item.Inst_Gebruikersnaam%><br />
C:
<%: item.Inst_Concode%><br />
D:
<%: item.Inst_DirCode%>
</td>
<%} %>
<td>
T:
<%: item.INST_TYPE%><br />
Inst_REF:
<%: item.INST_REF%><br />
Loc_REF:
<%: item.INST_LOC_REF%><br />
Loc_Nr:
<%: item.INST_LOCNR%>
</td>
<td>
<%: String.Format("{0:d}", item.DATUM_VAN)%>
-
<%: String.Format("{0:d}", item.DATUM_TOT)%>
</td>
<td>
<a href='<%= Url.Action("Links", "Instelling", MVC2_NASTEST.RouteValues.MergeRouteValues(MVC2_NASTEST.RouteValues.optionalParamters(Request.QueryString), new {id=item.Inst_ID})) %>'
title="Linken">
<img src="<%= Url.Content("~/img/link.png") %>" alt="Link" width="16" /></a>
</td>
</tr>
<% } %>
</table>
but this is MVC, my code is dry, what is the correct way to do this? or, what is a cleaner way to do this.

Answer 1

I would write a Html helper for this. It could look something like this:
public bool IsInRole(this HtmlHelper instance, params string[] roles)
{
var user = html.ViewContext.HttpContext.User;
foreach(var role in roles)
{
if(user.IsInRole(role))
return true;
}
return false;
}
This function will return true if user is in any of the provided roles. You would use it like this:
<tr>
<td>First - Visible to all</td>
<% if(Html.IsInRole("Admin", "Algemeen Beheer", "Secretariaat")) { %>
<td>Only for privileged users</td>
<% } %>
<td>Last - Visible to all
</tr>
This is a light, clean and reusable way of doing it.