add basic validation helper for checking against a schema definition

project.clj

@@ -7,4 +7,5 @@
   :dependencies [[org.clojure/clojure "1.6.0"]
                  [compojure "1.3.1" :scope "provided"]
                  [ring/ring-core "1.3.1" :scope "provided"]
-                 [cheshire "5.3.1"]])
+                 [cheshire "5.3.1"]
+                 [prismatic/schema "0.3.3"]])

src/clj_webtoolbox/routes/checked.clj

@@ -2,6 +2,7 @@
   (:require
     [compojure.core :refer [routing]]
     [ring.util.response :refer [response?]]
+    [schema.core :as s]
     [clj-webtoolbox.response :as response]
     [clj-webtoolbox.routes.core :refer [destructure-route-bindings]]))
 
@@ -99,6 +100,16 @@
       (if (f (get-in request k))
         (safe request parent [param])))))
 
+(defn validate-schema
+  "Validates the specified parameter by checking it against the given schema.
+   If it validates, the parameter is marked safe. Follows the same rules for
+   param/parent handling as validate."
+  ([request param schema] (validate-schema request :params param schema))
+  ([request parent param schema]
+    (let [k (if (sequential? param) (concat [parent] param) [parent param])]
+      (if (nil? (s/check schema (get-in request k)))
+        (safe request parent [param])))))
+
 (defn transform
   "Transforms the specified parameter using function f which gets passed the value
    of the parameter. A nested parameter can be transformed by specifying it as a