如何检测Silverstripe页面在Controller中作为父级或子级加载

Question

Our Silverstripe project has the following two page types:

class MultiSectionPage extends Page {
  private static $allowed_children = array(
    'Section'
  );

  public function PageSections() {
    $PageSections = Section::get()->filter(array('ParentID' => $this->ID));
    return $PageSections;
  }
}

class Section extends Page {
  public static $allowed_children = array();
  private static $show_in_sitetree = false;
}

In the Layout/MultiSectionPage.ss template the following code loops through each child Section as a dataobject:

<% loop $PageSections %>
<% include MultiSectionPage_Section %>
<% end_loop %>

I want to make sure that if anyone accidentally links to a Section it redirects to the parent MultiSectionPage.

class Section extends Page {
  public function Link() {
    return parent::Link() . '#section-' . $this->ID;
  }
}

class Section_Controller extends Page_Controller {

  public function init(){
    parent::init();

    if(!$this->getResponse()->isFinished() && $link = $this->Link()) {
        $this->redirect($link, 301);
        return;
    }
  }
}

However using this method triggers a redirect even when viewing the MultiSectionPage as the init must get called each time the Section DataObject is rendered.

How do I detect whether a Section Controller is being loaded as a standalone parent (redirect) or as child of a MultiSectionPage ?

Answer 1

The Section_Controller should not be getting called when viewing the MultiSectionPage. Only the Section object is loaded when looping through PageSections. When retrieving a DataList of DataObjects only their class is loaded, not their controller.

Note the Section_Controller should redirect to the parent page link, not the current page link. I would also recommend updating the Section Link function to return the parent link:

class Section extends Page {
    private static $allowed_children = array();
    private static $show_in_sitetree = false;

    public function Link($action = null) {
        return $this->Parent()->Link($action);
    }
}

class Section_Controller extends Page_Controller {
    public function init() {
        parent::init();

        return $this->redirect($this->Parent()->Link(), 301);
    }
}