Encoding problems with many_to_many for PaperTrail.update/2

[joshuataylor]

So I'm doing something like

ids = [1,2,3]
items = MyApp.Item |> where([p], p.id in ^ids) |> Repo.all
changeset = Ecto.Changeset.put_assoc(changeset, :items, items)

PaperTrail.update changeset

Now, when saving, it gives me the following error:
** (Poison.EncodeError) unable to encode value: {:assoc, %Ecto.Association.BelongsTo{cardinality: :one, defaults: [], field: :something, on_cast: nil, on_replace: :raise, owner: MyApp.Something, owner_key: :something_id, queryable: MyApp.Something, related: MyApp.Something, related_key: :id, relationship: :parent, unique: true}}

I've tried setting a custom encoder for my model/schema in my app with poison, but it doesn't seem to work for paper_trail.

What's the best way to handle this?

[izelnakri]

There is no relationship called :changeset in paper_trail. PaperTrail.insert , update and delete functions wrap your record insertion/edit in a database transaction and creates a row with associated data in the versions table. You shouldnt change the data manually like this.

[izelnakri]

closing this issue if you are ok with it, let me know if you would like it reopened

[jeremyjh]

@izelnakri We're struggling with the same issue. Joshua is not updating the data manually; he is using Ecto's put_assoc to populate a changeset. Papertrail does operate on changesets created with cast. If associations are not supported that is fine I guess but is this something you'd be open to a PR addressing (if its feasible) ?