Laravel return all the ids of descendants

Question

How do I return all the ids of AllSubSections (all levels)

class Section extends Model
{
    public function Ads()
    {
        return $this->hasMany(Ad::class);
    }

    public function AllSubSections()
    {
        return $this->SubSections()->with('AllSubSections');
    }

    public function SubSections()
    {
        return $this->hasMany(Section::class);
    }

    public function Parent()
    {
        return $this->belongsTo(Section::class);
    }
}

what am currently doing is :

$section = Section::where('name', 'Properties')->first();
$subSections = $section->AllSubSections;
$subSections->pluck('id')

but it only returns the 1st level not all the levels.

Answer 1

Here is what I came with:

use Illuminate\Support\Collection;

class Section
{
    public function children ()
    {
        return $this->hasMany(Section::class,);
    }

    public function parent ()
    {
        return $this->belongsTo(Section::class);
    }

    public function getAllChildren ()
    {
        $sections = new Collection();

        foreach ($this->children as $section) {
            $sections->push($section);
            $sections = $sections->merge($section->getAllChildren());
        }

        return $sections;
    }
}

As you can see, getAllChildren is a recursive function. It contains a loop over the section children that adds to the collection the current child and calls itself again on this child.

You can then use:

$section->getAllChildren()->pluck('id');

And you will get all your children ids.

I hope I am responding to the question!