meta-schema

Designed to help data processing using clojure.spec.

Provide users the ability to combine several pre-defined clojure.spec into some specific shape at runtime.

For now, it only supports JSON files.

Installation

Leiningen/Boot
[meta-schema "0.1.0-SNAPSHOT"]

Clojure CLI/deps.edn
meta-schema {:mvn/version "0.1.0-SNAPSHOT"}

Usage

In your project you need to define EDN files inside a folder and provide a list of java.io.Files to the (setup! ..) function. These files are simple and provides the location and intent of your pre-defined specs.

{:zipcode {:intent "Validation to ZipCodes in Brazil"
           :location :my-project.spec/zipcode-br}
 :money {:intent "How we understand money around here? Anything >= 0 either long, float, double, or decimal"
         :location :my-project.other-spec/money-br}
}

Make sure that all this namespaces are loaded before invoke meta-schema.core/setup!.

Example of specification provided to the library at runtime.

  (require '[meta-schema.core :as ms])
  (require '[clojure.alpha.spec :as s])
  (require '[clojure.java.io :as io])

  (ms/setup! (-> (io/resources "specs")
                 (io/file)
                 (file-seq)))

  (def file-spec {:spec-name :my-project.client/payload
                  :zip [{:spec :zipcode
                         :optional? false
                         :nullable? false}

                        {:house-price {:spec :money
                                       :nullable? true}}]

                  :rent {:spec :money
                         :optional? false
                         :nullable? false}

                  :university {:departments [{:zip {:address {:spec :zipcode
                                                              :optional? false}}}]}})

  (def my-parser (ms/create-parser file-spec))

  (def my-data-1 {:zip ["my zipcode is text"]
                  :rent 10
                  :university {:departments [{:zip {:address "deep structures"}}]}})

  (s/valid? my-parser my-data-1) ;; => true

  (s/valid? my-parser {:zip [{:house-price 230} "either or both here.."]
                       :rent 10
                       :university {:departments [{:zip {:address "deep structures"}}]}}) ;; => true

Rational

The DSL is simple:

1. When the field is a list, more than one spec inside it will produce a or operator
2. When the field is optional, it means that may or may not be present at coersion time
3. When the field is nullable, it means that nil is a valid input.
4. By default all the fields are not nullable and not optionals.
5. You can nest the options as you desired

TODO list

• [ ] Improve interfaces of public API
• [ ] Write a parser to spec the DSL in the input-file
• [ ] Provide support for sets and enums (?)
• [ ] Extend it to XML

License

Copyright © 2020 Wanderson Ferreira (@bartuka)

This program and the accompanying materials are made available under the terms of the Eclipse Public License 2.0 which is available at http://www.eclipse.org/legal/epl-2.0.

This Source Code may also be made available under the following Secondary Licenses when the conditions for such availability set forth in the Eclipse Public License, v. 2.0 are satisfied: GNU General Public License as published by the Free Software Foundation, either version 2 of the License, or (at your option) any later version, with the GNU Classpath Exception which is available at https://www.gnu.org/software/classpath/license.html.