allow a setter_fun in schema validator

allows to set values during validation

Author: lazedo

src/jesse.erl

@@ -88,13 +88,20 @@
                                              | ?not_found
                                              ).
 
+-type setter_fun() :: fun(( jesse_json_path:path()
+                          , json_term()
+                          , json_term()
+                          ) -> json_term())
+                    | undefined.
+
 -type option() :: {allowed_errors, allowed_errors()}
                 | {default_schema_ver, schema_ver()}
                 | {error_handler, error_handler()}
                 | {external_validator, external_validator()}
                 | {meta_schema_ver, schema_ver()}
                 | {parser_fun, parser_fun()}
-                | {schema_loader_fun, schema_loader_fun()}.
+                | {schema_loader_fun, schema_loader_fun()}
+                | {setter_fun, setter_fun()}.
 
 -type options() :: [option()].
 

src/jesse_schema_validator.erl

@@ -40,10 +40,11 @@
               , Options    :: [{Key :: atom(), Data :: any()}]
               ) -> {ok, jesse:json_term()}
                  | no_return().
-validate(JsonSchema, Value, Options) ->
+validate(JsonSchema, Value, Options0) ->
+  Options = [{with_value, Value} | proplists:delete(with_value, Options0)],
   State    = jesse_state:new(JsonSchema, Options),
   NewState = validate_with_state(JsonSchema, Value, State),
-  {result(NewState), Value}.
+  {result(NewState), jesse_state:get_current_value(NewState)}.
 
 %% @doc Validates json `Data' against `JsonSchema' with `State'.
 %% If the given json is valid, then the latest state is returned to the caller,

src/jesse_state.erl

@@ -27,6 +27,7 @@
 -export([ add_to_path/2
         , get_allowed_errors/1
         , get_external_validator/1
+        , get_current_value/1
         , get_current_path/1
         , get_current_schema/1
         , get_current_schema_id/1
@@ -37,6 +38,7 @@
         , remove_last_from_path/1
         , set_allowed_errors/2
         , set_current_schema/2
+        , set_value/3
         , set_error_list/2
         , resolve_ref/2
         , undo_resolve_ref/2
@@ -55,13 +57,15 @@
        , { allowed_errors :: jesse:allowed_errors()
          , current_path :: current_path()
          , current_schema :: jesse:schema()
+         , current_value :: jesse:json_term()
          , default_schema_ver :: jesse:schema_ver()
          , error_handler :: jesse:error_handler()
          , error_list :: jesse:error_list()
          , external_validator :: jesse:external_validator()
          , id :: jesse:schema_id()
          , root_schema :: jesse:schema()
          , schema_loader_fun :: jesse:schema_loader_fun()
+         , setter_fun :: jesse:setter_fun()
          }
        ).
 
@@ -146,6 +150,9 @@ new(JsonSchema, Options) ->
                                  , Options
                                  , ?default_schema_loader_fun
                                  ),
+  SetterFun = proplists:get_value( setter_fun
+                                 , Options
+                                 ),
   NewState = #state{ root_schema        = JsonSchema
                    , current_path       = []
                    , allowed_errors     = AllowedErrors
@@ -154,6 +161,7 @@ new(JsonSchema, Options) ->
                    , default_schema_ver = DefaultSchemaVer
                    , schema_loader_fun  = LoaderFun
                    , external_validator = ExternalValidator
+                   , setter_fun         = SetterFun
                    },
   set_current_schema(NewState, JsonSchema).
 
@@ -392,3 +400,19 @@ load_schema(#state{schema_loader_fun = LoaderFun}, SchemaURI) ->
 %% @private
 get_external_validator(#state{external_validator = Fun}) ->
   Fun.
+
+%% @doc Getter for `current_value'.
+-spec get_current_value(State :: state()) -> jesse:json_term().
+get_current_value(#state{current_value = Value}) ->
+  Value.
+
+-spec set_value(State :: state(), jesse:path(), jesse:json_term()) -> state().
+set_value(#state{setter_fun = undefined}=State, _Path, _Value) -> State;
+set_value(#state{current_value = undefined}=State, _Path, _Value) -> State;
+set_value( #state{ setter_fun = Setter
+                 , current_value = Value
+                 } = State
+         , Path
+         , NewValue
+         ) ->
+  State#state{current_value = Setter(Path, NewValue, Value)}.