How to programmatically hide a field from edit form based on current user permissions

Question

I have an event receiver that sets SPField values based on certain user choices. I'm trying to show/hide one field based on the current user's signed in permissions, but only when the list item is being edited.

First of all, what event does this apply to? Is it ItemAdding, ItemUpdating, ItemAdded, etc.? I've tried each of them with no luck.

    public override void ItemUpdating(SPItemEventProperties properties)
    {
        using (SPWeb web = properties.Web)
        {
            SPList list = properties.List;
            SPListItem item = properties.ListItem;
            SPField status = list.Fields["Site Status"];
            SPUser user = web.CurrentUser;
            bool authorized = list.DoesUserHavePermissions(user, SPBasePermissions.ManageWeb);

            if (list != null)
            {
                if (authorized == true)
                {
                    status.Hidden = true;
                    //status.ShowInEditForm = true;  this never works no matter what
                    status.Update();
                }
                else
                {
                    status.Hidden = false;
                    //status.ShowInEditForm = false;  this also never works no matter what
                    status.Update();
                }
            }
        }
    }

So I guess there are 2 questions here. First, what event does this apply to, and second what is wrong with the code?

Answer 1

Your best bet is to customize the Edit form of the list, and use JavaScript object model to show/hide field based on user permissions..

You can use SPSecurityTrimmedControl as shown here

Or you can use JavaScript/jQuery to hide the field after checking permissions.. See SharePoint 2010: Conditionally Hide Fields on Standard List Forms using jQuery.. It says 2010 but should apply to 2013..