Assigning Item Level Priviliges to SPListItem

Sometimes you might wanna assign item level permissions to a list item instead of using Elevated Priviliges block throughout the whole code. This might happen in case you need to temporarily give a user higher priviliges than she has.

Typical example would be to provide a site reader exceptional functionality on a specific list item. In this case you break role inheritance and give the permissions you want. Here is a little snippet for that:

======================================================================

RunWithElevatedPriv

 …using SPSite…
    …using SPWeb…

// Get current user obj
SPUser user = SPContext.Current.Web.CurrentUser;
// Get current user token
SPUserToken token = user.UserToken;
// Get current user principal
SPPrincipal principal = (SPPrincipal)SPContext.Current.Web.CurrentUser;
// Get current user role assignment
SPRoleAssignment RoleAssignment = new SPRoleAssignment(principal);
// Get Your Custom Role definition
int SiteContributorId = -1;
SPRoleDefinition RoleDefSiteContributor = new SPRoleDefinition();

foreach (SPRoleDefinition roleDef in web.RoleDefinitions)
   // Find Your Custom Role Definition id
   if (roleDef.Name == “Your Custom Role Name”)
      SiteContributorId = roleDef.Id;

if (SiteContributorId != -1) {
   RoleDefSiteContributor = web.RoleDefinitions.GetById(SiteContributorId);
   // Add Your Custom Role to role assignments
   RoleAssignment.RoleDefinitionBindings.Add(RoleDefSiteContributor);
}

if (!impersonatedListItem.HasUniqueRoleAssignments)
   // Break role inheritance
   impersonatedListItem.BreakRoleInheritance(true);

// Add Your Custom Role assignment to list item
impersonatedListItem.RoleAssignments.Add(RoleAssignment);

 // Update changes
impersonatedListItem.Update(); 

   …close using SPWeb…
…close using SPSite…

======================================================================

zieglers