How to programmatically add delete modify item permissions in SharePoint

Note: SPPrincipal can be either an SPUser or SPGroup Object

Breaking Inheritance

//specifies whether the item has unique security //or inherits its role assignments from a parent object. item.HasUniqueRoleAssignments //Stops inheriting permissions from parent object // if true, it will keep all existing users // false, to remove all users item.BreakRoleInheritance(true); //Removes the local role assignments //and reverts to role assignments from the parent object. item.ResetRoleInheritance();

Adding Permissions to an item

//SPGroup group = web.Groups[0]; //SPUser user = web.Users[0]; //SPUser user2 = web.EnsureUser("mangaldas.mano"); //SPUser user3 = web.EnsureUser("Domain Users"); ; //SPPrincipal[] principals = { group, user, user2, user3 }; public static void SetPermissions(this SPListItem item, IEnumerable<SPPRINCIPAL> principals, SPRoleType roleType) { if (item != null) { foreach (SPPrincipal principal in principals) { SPRoleDefinition roleDefinition = item.Web.RoleDefinitions.GetByType(roleType); SetPermissions(item, principal, roleDefinition); } } } public static void SetPermissions(this SPListItem item, SPUser user, SPRoleType roleType) { if (item != null) { SPRoleDefinition roleDefinition = item.Web.RoleDefinitions.GetByType(roleType); SetPermissions(item, (SPPrincipal)user, roleDefinition); } } public static void SetPermissions(this SPListItem item, SPPrincipal principal, SPRoleType roleType) { if (item != null) { SPRoleDefinition roleDefinition = item.Web.RoleDefinitions.GetByType(roleType); SetPermissions(item, principal, roleDefinition); } } public static void SetPermissions(this SPListItem item, SPUser user, SPRoleDefinition roleDefinition) { if (item != null) { SetPermissions(item, (SPPrincipal)user, roleDefinition); } } public static void SetPermissions(this SPListItem item, SPPrincipal principal, SPRoleDefinition roleDefinition) { if (item != null) { SPRoleAssignment roleAssignment = new SPRoleAssignment(principal); roleAssignment.RoleDefinitionBindings.Add(roleDefinition); item.RoleAssignments.Add(roleAssignment); } }

Deleting all user Permissions from an item

public static void RemovePermissions(this SPListItem item, SPUser user) { if (item != null) { RemovePermissions(item, user as SPPrincipal); } } public static void RemovePermissions(this SPListItem item, SPPrincipal principal) { if (item != null) { item.RoleAssignments.Remove(principal); item.SystemUpdate(); } }

Removing specific roles from an item

public static void RemovePermissionsSpecificRole(this SPListItem item, SPPrincipal principal, SPRoleDefinition roleDefinition) { if (item != null) { SPRoleAssignment roleAssignment = item.RoleAssignments.GetAssignmentByPrincipal(principal); if (roleAssignment != null) { if (roleAssignment.RoleDefinitionBindings.Contains(roleDefinition)) { roleAssignment.RoleDefinitionBindings.Remove(roleDefinition); roleAssignment.Update(); } } } } public static void RemovePermissionsSpecificRole(this SPListItem item, SPPrincipal principal, SPRoleType roleType) { if (item != null) { SPRoleDefinition roleDefinition = item.Web.RoleDefinitions.GetByType(roleType); RemovePermissionsSpecificRole(item, principal, roleDefinition); } }

Updating or Modifying Permissions on an item

public static void ChangePermissions(this SPListItem item, SPPrincipal principal, SPRoleType roleType) { if (item != null) { SPRoleDefinition roleDefinition = item.Web.RoleDefinitions.GetByType(roleType); ChangePermissions(item, principal, roleDefinition); } } public static void ChangePermissions(this SPListItem item, SPPrincipal principal, SPRoleDefinition roleDefinition) { SPRoleAssignment roleAssignment = item.RoleAssignments.GetAssignmentByPrincipal(principal); if (roleAssignment != null) { roleAssignment.RoleDefinitionBindings.RemoveAll(); roleAssignment.RoleDefinitionBindings.Add(roleDefinition); roleAssignment.Update(); } }