parent() returns an array of values relating to the parent page of the current page.¹⁾ Normally, then, it is not used on its own, but to give some information about the parent page.

$level must be initialized properly if it is to be used:

• If you do NOT supply $level, you simply get the parent object.
• If $level > $this->level(), you get FALSE.
• If $level == $this->level(), you get $this returned.
• Otherwise it tries the above tests with the parent object.

Thus, if a value is given for $level, it should be one of: null, equal-to-current-level, or greater-than-current-level.

For the following tree of pages:

Home Page
  |
  |- Hickory
  |    |
  |    |- Dickory
  |    |
  |    |- Dock
  |
  |- Clock

• when Clock is the current page, then:
  • $this->parent()->title() returns “Home Page”
  • $this->parent()->slug() returns ' ' (i.e., null)
  • $this->parent()->level() returns “0”
• when Dock is the current page, then:
  • $this->parent()->title() returns “Hickory”
  • $this->parent(2)->title() returns “Dock” (this page is at level 2)
  • $this->parent()->slug() returns “hickory”
  • $this->parent()->level() returns “1”
  • etc. …
• when Home Page is the current page, then:
  • $this->parent()->ANYTHING returns an ERROR (do not use it!)