backport src/compojure/api/coercion/schema.clj

Author: frenchy64

src/compojure/api/coercion/schema.clj

@@ -0,0 +1,88 @@
+(ns compojure.api.coercion.schema
+  (:require [schema.coerce :as sc]
+            [schema.utils :as su]
+            [ring.swagger.coerce :as coerce]
+            [compojure.api.coercion.core :as cc]
+            [clojure.walk :as walk]
+            [schema.core :as s]
+            [compojure.api.common :as common])
+  (:import (java.io File)
+           (schema.core OptionalKey RequiredKey)
+           (schema.utils ValidationError NamedError)))
+
+(def string-coercion-matcher coerce/query-schema-coercion-matcher)
+(def json-coercion-matcher coerce/json-schema-coercion-matcher)
+
+(defn stringify
+  "Stringifies Schema records recursively."
+  [error]
+  (walk/prewalk
+    (fn [x]
+      (cond
+        (class? x) (.getName ^Class x)
+        (instance? OptionalKey x) (pr-str (list 'opt (:k x)))
+        (instance? RequiredKey x) (pr-str (list 'req (:k x)))
+        (and (satisfies? s/Schema x) (record? x)) (try (pr-str (s/explain x)) (catch Exception _ x))
+        (instance? ValidationError x) (str (su/validation-error-explain x))
+        (instance? NamedError x) (str (su/named-error-explain x))
+        :else x))
+    error))
+
+(def memoized-coercer
+  (common/fifo-memoize sc/coercer 1000))
+
+;; don't use coercion for certain types
+(defmulti coerce-response? identity :default ::default)
+(defmethod coerce-response? ::default [_] true)
+(defmethod coerce-response? File [_] false)
+
+(defrecord SchemaCoercion [name options]
+  cc/Coercion
+  (get-name [_] name)
+
+  (get-apidocs [_ _ data] data)
+
+  (make-open [_ schema]
+    (if (map? schema)
+      (assoc schema s/Keyword s/Any)
+      schema))
+
+  (encode-error [_ error]
+    (-> error
+        (update :schema pr-str)
+        (update :errors stringify)))
+
+  (coerce-request [_ schema value type format request]
+    (let [type-options (options type)]
+      (if-let [matcher (or (get (get type-options :formats) format)
+                           (get type-options :default))]
+        (let [coerce (memoized-coercer schema matcher)
+              coerced (coerce value)]
+          (if (su/error? coerced)
+            (let [errors (su/error-val coerced)]
+              (cc/map->CoercionError
+                {:schema schema
+                 :errors errors}))
+            coerced))
+        value)))
+
+  (accept-response? [_ model]
+    (coerce-response? model))
+
+  (coerce-response [this schema value type format request]
+    (cc/coerce-request this schema value type format request)))
+
+(def default-options
+  {:body {:default (constantly nil)
+          :formats {"application/json" json-coercion-matcher
+                    "application/msgpack" json-coercion-matcher
+                    "application/x-yaml" json-coercion-matcher}}
+   :string {:default string-coercion-matcher}
+   :response {:default (constantly nil)}})
+
+(defn create-coercion [options]
+  (->SchemaCoercion :schema options))
+
+(def default-coercion (create-coercion default-options))
+
+(defmethod cc/named-coercion :schema [_] default-coercion)