Failed to acquire keys which have default value.

[defclass]

Hi, I have simple route below

Example:

(GET "/get_messages" []
     :query-params [{since :- s/Int nil}
                    {until :- s/Int nil}
                    {limit :- s/Int 20}
                    :as query-params]
     (prn query-params))

I have printed query-params Var at present , it seems didn't contains the keys which have default value.

Results:

curl /get_messages => {}
curl /get_messages?limit=10 => {:limit 10}

I expect :
curl /get_messages => {:limit 20}

Or I missed some configurations, thanks for reading this post.

[ikitommi]

Hi. This is originating from Plumbing fnk-syntax. Could you write issue there and link it to this issue? The corresponding plumbing code would be something like:

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

(defnk get_messages
  [{since :- s/Int nil}
   {until :- s/Int nil}
   {limit :- s/Int 20}
   :as query-params]
  query-params)

(get_messages {})
; {}

[ikitommi]

Also related:

• Handle Schema default values (was: How to compose parameters) #174
• Default values for Schemas schema-tools#25

e.g. we could add a coercer to compojure-api, which would apply the defaults, but that still doesn't woudn't populate the query-params in your example with fnk syntax as Plumbing separates coercion from destructuring. It would work only when you define the Schema as data like with :query:

(GET "/defaults" []
  :query [query-params {:limit (st/default s/Int 10)}]
  (prn query-params))

[Deraen]

IMO: Not a bug, works the same as Clojure default map destructuring:

(defn foo [{:keys [a b] :or {a 1 b 2} :as x}]
  x)

(foo {})
;; => {}

Default values from destructuring only work when referring the destructured value directly.

[defclass]

Hi Tommi, thanks for your speedy reply and excellent solution. I've read the related links you provided. It seems need Plumbing to provide this handy notation.

According to @Deraen 's opinion, maybe I went the wrong way, I'll try st/default, or provide default value in some other place where use query-params for now.

Cheers

[ikitommi]

Closing this, continues on #174