Merge pull request #278 from metosin/default-value-transformer-options

Options for default-value-transformer
metosin · Oct 13, 2020 · d3f9605 · d3f9605
2 parents 228a3a3 + 4397d26
commit d3f9605
Show file tree

Hide file tree

Showing 4 changed files with 73 additions and 27 deletions.
diff --git a/CHANGELOG.md b/CHANGELOG.md
@@ -19,6 +19,21 @@ Malli is in [alpha](README.md#alpha).
 * New options
   * `:malli.core/disable-sci` for explicitly disabling `sci`, fixes [#276](https://github.com/metosin/malli/issues/276)
   * `:malli.core/sci-options` for configuring `sci`
+* `malli.transform/default-value-transformer` accepts options `:key` and `:defaults`:
+
+```clj
+(m/decode
+  [:map
+   [:user [:map
+           [:name :string]
+           [:description {:ui/default "-"} :string]]]]
+  nil
+  (mt/default-value-transformer
+    {:key :ui/default
+     :defaults {:map (constantly {})
+                :string (constantly "")}}))
+; => {:user {:name "", :description "-"}}
+```
 
 ## 0.1.0 (2020-10-08)
 

diff --git a/README.md b/README.md
@@ -549,6 +549,22 @@ Applying default values:
 ; => 42
 ```
 
+With custom key and type defaults:
+
+```clj
+(m/decode
+  [:map
+   [:user [:map
+           [:name :string]
+           [:description {:ui/default "-"} :string]]]]
+  nil
+  (mt/default-value-transformer
+    {:key :ui/default
+     :defaults {:map (constantly {})
+                :string (constantly "")}}))
+; => {:user {:name "", :description "-"}}
+```
+
 Single sweep of defaults & string encoding:
 
 ```clj

diff --git a/src/malli/transform.cljc b/src/malli/transform.cljc
@@ -367,32 +367,36 @@
                        (= :default types) {:default-decoder (transform decode :enter)
                                            :default-encoder (transform encode :leave)}))))
 
-(defn default-value-transformer []
-  (let [get-default (fn [schema] (some-> schema m/properties :default))
-        set-default {:compile (fn [schema _]
-                                (if-some [default (get-default schema)]
-                                  (fn [x] (if (nil? x) default x))))}
-        add-defaults {:compile (fn [schema _]
-                                 (let [defaults (->> (m/children schema)
-                                                     (keep (fn [[k {:keys [default]} v]]
-                                                             (if-some [default (if (some? default) default (get-default v))]
-                                                               [k default])))
-                                                     (into {}))]
-                                   (if (seq defaults)
-                                     (fn [x]
-                                       (if (map? x)
-                                         (reduce-kv
-                                           (fn [acc k v]
-                                             (if-not (contains? x k)
-                                               (assoc acc k v)
-                                               acc))
-                                           x defaults)
-                                         x)))))}]
-    (transformer
-      {:default-decoder set-default
-       :default-encoder set-default}
-      {:decoders {:map add-defaults}
-       :encoders {:map add-defaults}})))
+(defn default-value-transformer
+  ([]
+   (default-value-transformer nil))
+  ([{:keys [key defaults] :or {key :default}}]
+   (let [get-default (fn [schema] (let [default (some-> schema m/properties key)]
+                                    (if (some? default) default (some->> schema m/type (get defaults) (#(% schema))))))
+         set-default {:compile (fn [schema _]
+                                 (if-some [default (get-default schema)]
+                                   (fn [x] (if (nil? x) default x))))}
+         add-defaults {:compile (fn [schema _]
+                                  (let [defaults (->> (m/children schema)
+                                                      (keep (fn [[k {default key} v]]
+                                                              (if-some [default (if (some? default) default (get-default v))]
+                                                                [k default])))
+                                                      (into {}))]
+                                    (if (seq defaults)
+                                      (fn [x]
+                                        (if (map? x)
+                                          (reduce-kv
+                                            (fn [acc k v]
+                                              (if-not (contains? x k)
+                                                (assoc acc k v)
+                                                acc))
+                                            x defaults)
+                                          x)))))}]
+     (transformer
+       {:default-decoder set-default
+        :default-encoder set-default}
+       {:decoders {:map add-defaults}
+        :encoders {:map add-defaults}}))))
 
 (defn collection-transformer []
   (let [coders {:vector -sequential-or-set->vector

diff --git a/test/malli/transform_test.cljc b/test/malli/transform_test.cljc
@@ -657,7 +657,18 @@
   (testing "default false"
     (is (= {:user/verified false} (m/decode [:map [:user/verified [:and {:default false} boolean?]]] {} mt/default-value-transformer)))
     (is (= {:user/verified false} (m/decode [:map [:user/verified {:default false} boolean?]] {} mt/default-value-transformer)))
-    (is (= false (m/decode [:and {:default false} boolean?] nil mt/default-value-transformer)))))
+    (is (= false (m/decode [:and {:default false} boolean?] nil mt/default-value-transformer))))
+
+  (testing "with custom options"
+    (is (= false (m/decode [:and {:? false} boolean?] nil (mt/default-value-transformer {:key :?}))))
+    (is (= {:user {:first-name "", :last-name ""}}
+           (m/decode [:map
+                      [:user [:map
+                              [:first-name :string]
+                              [:last-name :string]]]]
+                     nil
+                     (mt/default-value-transformer {:defaults {:map (constantly {})
+                                                               :string (constantly "")}}))))))
 
 (deftest type-properties-based-transformations
   (is (= 12 (m/decode malli.core-test/Over6 "12" mt/string-transformer))))