在安装的profile阶段，将运行我们在university_profile_task_list()中指定的任务。在该阶段期间，安装器将重复的调用university_profile_tasks()，并向其传递参数$task和$url，其中$task变量包含了任务名字，而$url则是一个在表单函数中可能用到的URL。安装器初次调用它时，$task将包含字符串profile。
每个任务完成后，Drupal将使用includes/install.inc中的install_goto()请求浏览器来执行一个HTTP重定向，接着在进入下一个任务以前执行一个完整的引导指定。当所有的任务都完成以后，$task将被设置为profile-finished，安装器将停止对university_profile_tasks()的调用并继续前进。
下面是university_profile_tasks()的一个骨架：
function university_profile_tasks(&$task, $url) {
if ($task == 'profile') {
// The value of $task is 'profile' the first time we are called.
// Set up all the things a default installation profile has.
require_once 'profiles/default/default.profile';
default_profile_tasks($task, $url);
// Then do our custom setup here.
// Set $task to the next task.
$task = 'dept-info';
// Display a form requesting some info.
return drupal_get_form('university_department_info', $url);
}
if ($task == 'dept-info') {
// Send email indicating that a site was set up.
// Set $task to key of next task.
$task = 'support-message';
// Build some output.
return $output;
}
if ($task == 'support-message') {
// Return control to the installer.
$task = 'profile-finished';
}
}
由于我们想要的大多数设置都与平时的Drupal站点一样，所以我们加载了Drupal的默认轮廓，并简单的调用default_profile_tasks()，而不是在我们的安装轮廓中重复所有的代码。另外的一种方式就是将默认轮廓中的代码复制粘贴到第一个任务中。
提示 一个简单的安装轮廓不需要实现多个任务。在它被调用时，它可以忽略传递给它的参数并运行代码。当安装器看见$task变量没有改变的话，它将继续前进，运行后面的安装轮廓步骤。Drupal的默认安装轮廓就是这样的一个轮廓，所以我们可以直接在这里调用default_profile_tasks()，而不用担心它会修改$task的值。
注意前面代码中的结构。它包含了一系列的if语句，每一个语句对应一个任务。在每个任务的结尾处，通过引用传递的$task变量，此时将被修改，并返回任意输出，这样将生成一个附加的界面供用户进行交互。
由于在自定义安装任务运行以前，已经设立了数据库并建立了连接，所以，安装器可以在每个任务的结尾处调用variable_set('install_task', $task)，使用一个持久化变量来追踪当前任务的名字。如果你想从一个任务中向另一个任务传递信息的话，那么也可以使用这一技术。只要记住，在你最后一个任务的结尾处，使用variable_del()来删除你用过的变量，这样就可以了。
下面是大学安装轮廓的university_profile_tasks()函数的完整版本，让我们仔细的学习一下：
/**
* Perform final installation tasks for this installation profile.
*/
function university_profile_tasks(&$task, $url) {
if ($task == 'profile') {
// $task is set to 'profile' the first time this function is called.
// Set up all the things a default installation profile has.
require_once 'profiles/default/default.profile';
// Need constants defined by modules/comment/comment.module
// to be in scope.
require_once 'modules/comment/comment.module';
default_profile_tasks($task, $url);
// If the administrator enables the comment module, we want
// to have comments disabled for pages.
variable_set('comment_page', COMMENT_NODE_DISABLED);
// Define a News Item node type.
$node_type = array(
'type' => 'news',
'name' => st('News Item'),
'module' => 'node',
'description' => st('A news item for the front page.'),
'custom' => TRUE,
'modified' => TRUE,
'locked' => FALSE,
'has_title' => TRUE,
'title_label' => st('Title'),
'has_body' => TRUE,
'orig_type' => 'news',
'is_new' => TRUE,
);
node_type_save((object)$node_type);
// News items should be published and promoted to front page by default.
// News items should create new revisions by default.
variable_set('node_options_news', array('status', 'revision', 'promote'));
// If the administrator enables the comment module, we want
// to have comments enabled for news items.
variable_set('comment_news', COMMENT_NODE_READ_WRITE);
// Create a News Categories vocabulary so news can be classified.
$vocabulary = array(
'name' => st('News Categories'),
'description' => st('Select the appropriate audience for your news item.'),
'help' => st('You may select multiple audiences.'),
'nodes' => array('news' => st('News Item')),
'hierarchy' => 0,
'relations' => 0,
'tags' => 0,
'multiple' => 1,
'required' => 0,
);
taxonomy_save_vocabulary($vocabulary);
// Define some terms to categorize news items.
$terms = array(
st('Departmental News'),
st('Faculty News'),
st('Staff News'),
st('Student News'),
);
// Submit the "Add term" form programmatically for each term.
$form_id = 'taxonomy_form_term';
// The taxonomy_form_term form is not in taxonomy.module, so need
// to bring it into scope by loading taxonomy.admin.inc.
require_once 'modules/taxonomy/taxonomy.admin.inc';
foreach ($terms as $name) {
$form_state['values']['name'] = $name;
$form_state['clicked_button']['#value'] = st('Save');
drupal_execute($form_id, $form_state, (object)$vocabulary);
}
// Add a role.
db_query("INSERT INTO {role} (name) VALUES ('%s')", 'site administrator');
// Configure the pubcookie module.
variable_set('pubcookie_login_dir', 'login');
variable_set('pubcookie_id_is_email', 1);
// ...other settings go here
// Set $task to next task so the installer UI will be correct.
$task = 'dept-info';
drupal_set_title(st('Departmental Information'));
return drupal_get_form('university_department_info', $url);
}
if ($task == 'dept-info') {
// Report by email that a new Drupal site has been installed.
$to = 'administrator@example.com';
$from = ini_get('sendmail_from');
$subject = st('New Drupal site created!');
$body = st('A new Drupal site was created: @site', array(
'@site' => base_path()));
drupal_mail('university-profile', $to, $subject, $body, $from);
// Set $task to next task so the installer UI will be correct.
$task = 'support-message';
drupal_set_title(st('Support'));
$output = '<p>'. st('For support, please contact the Drupal Support Desk
at 123-4567.') .'</p>';
// Build a 'Continue' link that goes to the next task.
$output .= '<p>'. l(st('Continue'), $url) .'</p>';
return $output;
}
if ($task == 'support-message') {
// Change to our custom theme.
$themes = system_theme_data();
$theme = 'university';
if (isset($themes[$theme])) {
system_initialize_theme_blocks($theme);
db_query("UPDATE {system} SET status = 1 WHERE type = 'theme' AND
name = '%s'", $theme);
variable_set('theme_default', $theme);
menu_rebuild();
drupal_rebuild_theme_registry();
}
// Return control to the installer.
$task = 'profile-finished';
}
}
