datamapper/dm-is-tree

DataMapper plugin allowing the creation of tree structures from data models

dm-is-tree's Issues

Option for destroying parent and children

Would be useful to have something like

is :tree, :dependent => :destroy

for cases where you'd like to "prune" your tree

Constraints?

It would be awesome if dm-is-tree was compatible with dm-constraints!
I was able to add a constraint to protect nodes with children by repeating the children relationship like this:

is :tree
has n, :children, :model => self, :child_key => :parent_id, :constraint => :protect

However, it would be much more convenient if one could simply say:

is :tree, :constraint => :protect

Eager Load entire tree?

I've got a page where I need to display all elements in a table, and it just takes forever to load, partly because it issues a separate query to retrieve each node's children. I imagine it would go much faster to load all the rows at once, and then associate them based on their parent_ids. This, of course, isn't a good solution if you need to load only 10% of a large table, and there's no way to determine which rows need to be loaded without checking for parent_ids one query at a time.

To solve that it might be a good idea to setup something like "eager-loading sets" where you could tag each instance with a set name, so you could eager load a named set... or something.

But for starters, just eager loading the whole table would be awesome.