Sequel support about logidze

[palkan]

I'd prefer to start with Sequel support within this gem.
Otherwise we have to extract core functionality into, say, logidze-core and thus support at least 3 gems: logidze (for ActiveRecord), logidze-core and logidze-sequel. And most of the features would require changes in both core and specific adapter projects.

Can you describe, please, how do you expect Logidze to work with Sequel?

[akxcv]

We could start by using sequel-rails. It provides a migration API that is almost identical to ActiveRecord's one.
For database queries and models we could probably use adapters.

For example:

Logidze::DB.transaction do
  Logidze::DB.execute(...)
end

The DB abstraction would pick the right adapter to use automatically.

I think, much of the difficulty will be in testing. It's not hard to rewrite tests for Sequel, I just don't quite know how to organize them.

[palkan]

First of all, we should extract SQL generation from migrations to make it possible to use them in both AR and Sequel migrations without any modification. Smth like:

class LogdizeAR < ActiveRecord::Migration
  def up
    execute Logidze::SQ::Install.up(upgrade: true)
  end

  def down
    execute Logidze::SQL::Install.down
  end
end

Sequel.migration do
  up { run Logidze::SQL::Install.up(upgrade: true) }
  down { run Logidze::SQL::Install.down }
end

We can event do that the Rails way using custom commands:

class LogdizeInstall < ActiveRecord::Migration
  def change
    create_logidze
  end
end

class LogdizePost < ActiveRecord::Migration
  def change
    add_logidze :posts, timestamp_column: :published_at, whitelist: %w(title body)
  end
end

[akxcv]

Actually, we don't have to extract any SQL. I was able to create a Sequel migration just by changing:

class <%= @migration_class_name %> < ActiveRecord::Migration
  require 'logidze/migration'
  include Logidze::Migration

  def up
    # stuff
  end
  
  # ...
end

To:

require 'logidze/migration'
include Logidze::Migration

Sequel.migration do
  up do
    # exactly the same stuff
  end
  # ...
end

So maybe we should extract everything but SQL generation since it's the same anyways?

[palkan]

Sorry, I don't understand what do you mean by "extract everything but SQL generation"

[akxcv]

On a second thought, my idea is pretty weird. :)
You are right, we should extract SQL generation into separate erb templates.

[akxcv]

I guess we should do the same for all ActiveRecord invocations.

We'll need a database wrapper to encapsulate ActiveRecord::Base.connection and Sequel::Model.db (Logidze::DB?). Also, we'll need a model wrapper to encapsulate ActiveRecord::Base and Sequel::Model (Logidze::Model if we rename the existing module to Logidze::ModelExtensions?)

How should we detect which one to use, AR or Sequel?

[akxcv]

An update on this: sequel-rails doesn't seem to be actively maintained, and, most likely, isn't used much. Looks like we'll have to go without it.