Laravel cant flatten array after collection->forget - laravel

Question

I have a loop inside loop on Laravel collection, and sometimes i need to delete some objects from second loop collection. Here is the code
public function remove_if_found($id)
{
$all_groups = Group::all();
$all_groups->load('templates');
foreach ($all_groups as $group)
{
foreach ($group->templates as $key => $template)
{
if($template->id = $id)
{
$group->templates->forget($key);
}
}
}
return $all_groups;
}
The problem is that collection of group->templates turns from simple(not assoc) array to object. Here is example how response looks
I am trying to flatten $group->templates->flatten() but in final response templates are still as object but not as array.
This test flatten works
...
foreach ($all_groups as $group)
{
foreach ($group->templates as $key => $template)
{
if($template->id = $id)
{
$group->templates->forget($key);
}
}
return $group->templates->flatten()//This code works i get fluttened array
}
But final variant still returns me object instead of array
$all_groups = Group::all();
$all_groups->load('templates');
foreach ($all_groups as $group)
{
foreach ($group->templates as $key => $template)
{
if($template->id = $id)
{
$group->templates->forget($key);
}
}
$group->templates->flatten()//Use flatten here
}
return $all_groups;//Templates are returned not as an array but still as an object (Same variant as on attached image)
}

Answer 1

Use values() to reset the keys and setRelation() to replace the relationship:
public function remove_if_found($id)
{
$all_groups = Group::all();
$all_groups->load('templates');
foreach ($all_groups as $group)
{
foreach ($group->templates as $key => $template)
{
if($template->id = $id)
{
$group->setRelation('templates', $group->templates->forget($key)->values());
}
}
}
return $all_groups;
}
You can also use except() instead of forget():
public function remove_if_found($id)
{
$all_groups = Group::all();
$all_groups->load('templates');
foreach ($all_groups as $group)
{
$group->setRelation('templates', $group->templates->except($id));
}
return $all_groups;
}