Collection::makeTree() hits database for each child

[ritterg]

I use ->getDescendants()->toTree() to get the whole tree and show it as a hierarchical list of checkboxes.
Up to version 5.1.1 this was one database hit (to get descendants).
select * from termsinner jointerm_closureonterm_closure.descendant=terms.idwhereterm_closure.ancestor= 1 andterm_closure.depth > 0

In version 6 it is now one database hit (to get descendants, same as above) and one database hit for each child
select * from termswhereterms.parent_id= 2 andterms.parent_id is not null

This makes building a larger tree very slow.

The problem seems to be on line 174 of Collection.php:
$result[$parentId]->children->add($item);
which used to be (in 5.1.1, Collection.php line 80)
$result[$parentId]->appendRelation($item->getChildrenRelationIndex(), $item);

Is there a way to get the tree without all these database hits?

[ritterg]

I was able to improve the speed of ->toTree() by loading the children relation on the descendants collection before calling toTree().

So instead of
$root->getDescendants()->toTree()
I do
$descendants = $root->getDescendants();
$descendants->load('children');
$tree = $descendants->toTree();

Still not as good as it was in 5.1.1, but much better than without loading children (now 2 database queries instead of 1 + (number of descendants))

[franzose]

Hello, @ritterg! It seems it's a regression :/ I'm going to fix it and make a new release.

[ritterg]

I can confirm that this (Version 6.0.1) fixes my issue.
Thanks for the quick fix.

[franzose]

You're welcome!