External Login

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// get the first four characters of the users name

$username = $form_state['input']['name'];

$testname = drupal_substr(drupal_strtolower($username),0,4);

// check to see if the person is a dave if ($testname == "dave") {

//if it’s a dave then use the external_login_register function

//to either log the person in or create a new account if that

//person doesn’t exist as a Drupal user

user_external_login_register($username, ‘authdave’); return TRUE;

}else { return FALSE;

}

}

In the authdave module (see Figure 6-5), we simply swap out the second validation handler for our own. Compare Figure 6-5 with Figure 6-3, which shows the local user login process.

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CHAPTER 6 ■ WORKING WITH USERS

Figure 6-5. Path of execution for external login with a second validation handler provided by the authdave module (compare with Figure 6-3)

The function user_external_login_register() is a helper function that registers the user if this is the first login and then logs the user in. The path of execution is shown in Figure 6-6 for a hypothetical user davejones logging in for the first time.

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CHAPTER 6 ■ WORKING WITH USERS

If the username begins with “dave” and this is the first time this user has logged in, a row in the users table does not exist for this user, so one will be created. However, no e-mail address has been provided like it was for Drupal’s default local user registration, so a module this simple is not a real solution if your site relies on sending e-mail to users. You’ll want to set the mail column of the users table so you will have an e-mail address associated with the user. To do this, you can have your module respond to the insert operation of the user hook, which is fired whenever a new user is inserted:

/**

* Implements hook_user_insert(). */

function authdave_user_insert(&$edit, &$account, $category = NULL) { global $authdave_authenticated;

if ($authdave_authenticated) {

$email = mycompany_email_lookup($account->name);

// Set e-mail address in the users table for this user. db_update('users')

->fields( array(

'mail' => $email,

)

)

->condition('uid', $account->uid) ->execute();

}

}

Savvy readers will notice that there is no way for the code to tell whether the user is locally or externally authenticated, so we’ve cleverly saved a global variable indicating that our module did authentication. We could also have queried the authmap table like so:

db_query("SELECT uid FROM {authmap} WHERE uid = :uid AND module = :module", array(':uid' => $account->uid, 'module' => 'authdave');

All users who were added via external authentication will have a row in the authmap table as well as the users table. However, in this case the authentication and hook_user_insert run during the same request, so a global variable is a good alternative to a database query.

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CHAPTER 6 ■ WORKING WITH USERS

Figure 6-6. Detail of the external user login/registration process

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