bguthrie / denton

Simple persistence middleware for Clojure.

denton

Denton is simple persistence middleware for Clojure. It supplies a basic protocol, Persistable, and structures related concerns like logging, SQL parsing, object mapping, and lifecycle events as a series of wrappers applied to a core implementation of that protocol, much like Ring does with HTTP requests.

Denton is designed to be lightweight but has strong opinions about logging (essential), raw SQL (avoid), and macros with side effects (avoid at all costs). It does not provide any infrastructure for managing "models", but does include several helpful faculties that clojure.jdbc leaves out.

The base Persistable protocol defines six functions:

• update-all: Given a query and a map of values, updates the record and returns the updated values.
• insert: Given a map of values, inserts the record and returns the updated values.
• delete: Given a query, deletes all records that match it and returns the number affected.
• find-one: Given a query, returns the first record matching it.
• find-all: Given a query, returns all records matching it.
• count-all Given a query, returns the count of records matching it.

In addition, Denton defines several other user-friendly helper functions, like save, that act on reified persistables.

Usage

(require '[denton.core :refer :all])

(def users
  (-> (sql-db env/database-url)
      (wrap-with-honey "users")
      (wrap-with-logging println "users")
      (wrap-with-serialize case/->snake_case_keyword case/->camelCaseKeyword)
      (wrap-with-lifecycle {:after-delete #(chatbot/notify "User " (:id %) " deleted")})
      ))

(find-all users [:= :id 1])                  #=> [{:id 1 ...}]
(find-by-id users 1)                         #=> {:id 1 ...}
(save users {:name "Guybrush Threepwood"})   #=> {:id 3 :name "Guybrush Threepwood"}
(save users {:id 1 :name "Herman Toothrot"}) #=> {:id 3 :name "Herman Toothrot"}

Name

What's in a name? The best-ever death metal band out of Denton never settled on a name.

License

Copyright © 2014 Brian Guthrie

Distributed under the Eclipse Public License either version 1.0 or (at your option) any later version.