Get rid of global options atom (korma.config)

[immoh]

Having global options doesn't make much sense, as options can be defined on db level and there is a global default db. Options are really database specific, having global options only makes things harder to implement correctly (e.g. #282)

This is a breaking change.

Most likely will be a bit tricky to implement because korma.sql.engine relies on fallback to korma.config/options.

See more discussion in #299.

[k13gomez]

take a look at this approach on #306, I removed the korma.config/options global atom and used the new get-options function throughout the stack which relies on a combination of dynamic binding vars, query/db arguments, or fallback to the get-defaults multimethod.

Using a multimethod would allow someone using the API to override the defaults for a given subprotocol based on their needs (there's a test written to demonstrate this approach). We could also pre-package different best-practice defaults for the different subprotocols by defining multimethods accordingly.

[k13gomez]

See my latest commit, should be closer to what you're looking for.

[gfZeng]

IMO, global config options is necessary. And korma.db/->name should definition as:

;;; korma/db.clj
(defn- ->naming [strategy]
  (merge (:namimg options) strategy))

[immoh]

I would like to hear why.

[gfZeng]

@immoh

(require '[korma.config :as kconf])

;;; set default naming
(kconf/set-naming {:keys underscore->dash :fields dash->underscore})

(db/defdb pg (db/postgres DB-SPEC))
;;; now query will use default naming strategy

[immoh]

It doesn't explain why it should be global. In my opinion the naming strategy is related to how the used database expects entities (tables, fields) to be named (uppercase, underscore etc.) hence it is related to database connection and should be defined in the spec.

[gfZeng]

Naming strategy is a transform for field names. which can affect input and output. It should be careless by api users.

the db-spec should shared with every api users. well, Naming strategy should can be customized. API provider just provider default options.