IsUserInRole calls GetRolesForUser?

Question

When I implement the RoleProvider class and call Roles.IsUserInRole(string username, string roleName), code execution first goes to the method 'GetRolesForUser(string username)'. Why is this? I don't want to iterate all roles when I am just looking for the single value of whether that user belongs in one role. Is this a limitation of .NET's role provider class or is there something I can do to control the execution of code a bit more?

Here's the calling code

if (Roles.IsUserInRole(CurrentUser.UserName, "Teacher")) {

And here's the implementation of IsUserInRole

public override bool IsUserInRole(string username, string roleName) { return true; }

But the code GetRolesForUser always gets implemented first:

public override string[] GetRolesForUser(string username) {
        string[] roles = GetAllRoles();
        List<string> userRoles = new List<string>();
        foreach (string role in roles) {
            if (IsUserInRole(username, role)) {
                userRoles.Add(role);
            }
        }
        return userRoles.ToArray();
    }

Answer 1

The RoleProvider.IsUserInRole(username, password) is used for checking roles for a given user which is not the current loggon user(for current logon user, it also use the Principal.IsInRole instead). And for RolePrincipal, it always use the GetRolesForUser to cache the roles and do the role checking among the cached role list. (source)

can user Roles.Provider.IsUserInRole instead of Roles.IsUserInRole

Answer 2

There's a layer Microsoft's role provider solution that enables caching a user's roles in a cookie so it doesn't need to call the provider's GetRolesForUser method. I believe the cookie caching is part of the Roles class, so as long as you implement from the RoleProvider base class, it should be compatible. It's worth a look at the code in reflector to get an idea of how MS implements their own abstract classes, and what the static helper classes do (Roles and Membership)

Try adding cacheRolesInCookie="true" to the roleManager element in your config file, and see if the flow changes.

Since you're using your own implementation of a RoleProvider, you can also override the IsUserInRole method and provide your own implementation of checking if a user is in a role.

UPDATE: This block of code gets called inside the Roles.IsUserInRole method:

IPrincipal currentUser = GetCurrentUser();
if (((currentUser != null) && (currentUser is RolePrincipal)) && ((((RolePrincipal) currentUser).ProviderName == Provider.Name) && StringUtil.EqualsIgnoreCase(username, currentUser.Identity.Name)))
{
    flag = currentUser.IsInRole(roleName);
}
else
{
    flag = Provider.IsUserInRole(username, roleName);
}

The else block is what will call your custom provider's IsUserInRole method.

So the roles for your user have not yet been added to the Principal object. If you just haven't gotten around to that step yet, OK. If not, make sure you do that. It will make sure that every time you call Roles.IsUserInRole, or User.IsInRole that those functions will use an in-memory cache of the roles for the user (once loaded) instead of having to go to the database every time. (Although the base role provider and Roles manager class should take care of this for you.)

Can you verify the config file settings for the role provider? Also, what version of .net are you using? Are you manually managing the login process or are you using the .net login control? Have you implemented a custom Roles class? Or are you using the System.Web.Security.Roles?