Multiple Actions (Forms) on one Page - How not to lose master data, after editing detail data?

Question

Hello all,

I've got a form where users can edit members of a group.

So they have the possibilty to add members or remove existing members. So the Url goes like ".../Group/Edit/4" Where 4 is the id of the group.

the view looks like this

<asp:Content ID="Content2" ContentPlaceHolderID="MainContent" runat="server">
<% using (Html.BeginForm("AddUser", "Group")) %>
    <%{%>
        <label for="newUser">User</label>
        <%=Html.TextBox("username")%>
        <input type="submit" value="Add"/>
    </div>
    <%}%>

    <% using (Html.BeginForm("RemoveUser", "Group")) %>
    <%{%>
    <div class="inputItem">
        <label for="groupMember">Bestehende Mitglieder</label>
        <%= Html.ListBox("groupMember", from g in Model.GetMembers() select new SelectListItem(){Text = g}) %>
        <input type="submit" value="Remove" />
    </div>
    <%}%>
</asp:Content>

The problem is that after adding or removing one user i lose the id of the group. What is the best solution for solving this kind of problem? Should I use hidden fields to save the group id?

Thanks in advance.

Answer 1

Hidden fields are a good way of persisting the id during posts.

Answer 2

You could use a hidden field or you could just parse the value into your route. I'm not sure how you're parsing the group id to the view but it would look something like:

<% using (Html.BeginForm("AddUser", "Group", new { groupId = Model.GroupID })) { %>

Then your controller will look something like this using the PRG pattern

[HttpGet]
public ViewResult Edit(int groupId) {
  //your logic here

  var model = new MyModel() {
    GroupID = groupId
  };
  return View("Edit", model);
}

[HttpPost]
public ActionResult AddUser(int groupId, string username) {
  //your logic here
  return RedirectToAction("Edit", new { GroupID = groupId });
}

[HttpPost]
public ActionResult RemoveUser(int groupId, string username) {
  //your logic here
  return RedirectToAction("Edit", new { GroupID = groupId });
}

The advantage to this method is that it's more RESTful