Question

i have the following array structure:

   |  ID  |  CategoryName  | ParentID 
    _________________________________
       1  |  Movies        | -1
    _________________________________
       2  |  Series        | -1
    _________________________________
       3  |  ActionMovies  |  1
    _________________________________
       4  |  HorrorMovies  |  1
    _________________________________
       5  |  ComedySeries  |  2
    _________________________________
       6  |  TVShows       | -1

My goal is to reach the following structure

Goal:

   |  ID  |  CategoryName  | ParentID 
    _________________________________
       1  |  Movies        | -1
    _________________________________
       3  |  ActionMovies  |  1
    _________________________________
       4  |  HorrorMovies  |  1
    _________________________________
       2  |  Series        | -1
    _________________________________
       5  |  ComedySeries  |  2
    _________________________________
       6  |  TVShows       | -1

Or explained in word:

• Parent-Categories have ParentID = -1 (Example Movies)
• All categories keep their original ID-Number
• Should come listed directly after their ParentCategory (Example ActionMovies)
• RootCategories without Children, come listed at the end of array. (Example TVShows)

How can i achieve this best with PHP? I have no access to the original Mysql query, so that is not an option 🙂

i have started with this code, but i am not sure it is the right path, and with minimal efforts/readability

        $tmpList = Categories_Models_Main::getAllCategories();



    $categoryData = array();
    foreach ($tmpList as $index => $categoryObject) {
        $categoryData[] = array('id' => $categoryObject->id,
                                 'CategoryName' => $categoryObject->parentId,
                                 'name' => $categoryObject->name);


    }

    ///let us assume $categoryData is original state.

    ///Beginning of manipulation and re-sorting of $tmpList


    foreach ($categoryData as $key => $value) {

        $mainId[$key] = $value['id'];

        $parentId[$key] = $value['parentId'];

    }

    array_multisort($parentId, $mainId, $categoryData);

Answer 1

Split the main array into two, one with those nodes that doesn’t have childs and other with rests of items.

Do the sorting into array of items with array_multisort function and do too a sorting into array of categories without childs using the criteria that you want. The final step will be push the array without childs to the other.

This form isn’t the most efficient, but to have a first approach is valid, after this, you can dispense time optimizing the code.