ZennerIoT/ex_audit

Restricting tracked_schemas makes versions unloadable

schnittchen opened this issue · 4 comments

schnittchen commented

Trying to load such a version results in the error

cannot load `"no_longer_tracked_schema"` as type ExAudit.Type.Schema for field :entity_schema in ...

The reason is that the old schema is no longer returned here https://github.com/ZennerIoT/ex_audit/blob/master/lib/repo/schema_type.ex#L18

narrowtux commented

Hi! I'm sorry you're having an issue with loading old versions.

Can you provide more details about your issue:

  • which function are you calling and how?
  • (if applicable) how did you configure ex_audit?
  • add the entire error message
schnittchen commented

I'm just calling MyApp.Version |> MyApp.Repo.all and the error I get is

cannot load `"some_table_name"` as type ExAudit.Type.Schema for field :entity_schema in %MyApp.Version{...}

(obviously with some real table name)

The error is easy to reproduce:

  • have something tracked
  • clear the tracked_schemas config
  • run the query

Aside, the version_schema and tracked_schemas should not be configuration for the ex_audit application but somehow bound to the Repo at hand (see https://hexdocs.pm/elixir/1.9.1/library-guidelines.html#avoid-application-configuration)

narrowtux commented

I feel like this might be out of spec for this library. If you remove a schema from the config, you should also write a migration that deletes all of these entries (the execute function can be used in ecto migrations to run arbitrary SQL queries):

DELETE FROM versions WHERE entity_schema= 'some_table_name'

Of course, you could also decide to keep these in a seperate table before deleting them from the versions table:

CREATE TABLE some_table_name_versions AS (SELECT * FROM versions WHERE entity_schema = 'some_table_name');
schnittchen commented

I just ran into this issue again after renaming a table. I had to go down to SQL to fix this, because the ExAudit.Type.Schema won't let me just add an arbitrary atom into the :tracked_schemas env.