[elm] add function to allow more fine grained error handling

Created by: 7omb

This is a backwards compatible change. It adds the additional function sendWithCustomExpect to the provided helper functions in Api.elm to make requests.

It can be used to implement a more fine grained error handling as described here. Before it was e.g. not possible to access the response body if the server responded with an error like 404.

@eriktim

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modules/openapi-generator/src/main/resources/elm/Api.mustache

@@ -3,6 +3,7 @@ module Api exposing
     , request
     , send
     , sendWithCustomError
+    , sendWithCustomExpect
     , task
     , map
     , withBasePath
@@ -55,13 +56,18 @@ send toMsg req =
 
 
 sendWithCustomError : (Http.Error -> e) -> (Result e a -> msg) -> Request a -> Cmd msg
-sendWithCustomError mapError toMsg (Request req) =
+sendWithCustomError mapError toMsg req =
+    sendWithCustomExpect (expectJson mapError toMsg) req
+
+
+sendWithCustomExpect : (Json.Decode.Decoder a -> Http.Expect msg) -> Request a -> Cmd msg
+sendWithCustomExpect expect (Request req) =
     Http.request
         { method = req.method
         , headers = req.headers
         , url = Url.Builder.crossOrigin req.basePath req.pathParams req.queryParams
         , body = req.body
-        , expect = expectJson mapError toMsg req.decoder
+        , expect = expect req.decoder
         , timeout = req.timeout
         , tracker = req.tracker
         }

samples/openapi3/client/elm/src/Api.elm

@@ -3,6 +3,7 @@ module Api exposing
     , request
     , send
     , sendWithCustomError
+    , sendWithCustomExpect
     , task
     , map
     , withBasePath
@@ -55,13 +56,18 @@ send toMsg req =
 
 
 sendWithCustomError : (Http.Error -> e) -> (Result e a -> msg) -> Request a -> Cmd msg
-sendWithCustomError mapError toMsg (Request req) =
+sendWithCustomError mapError toMsg req =
+    sendWithCustomExpect (expectJson mapError toMsg) req
+
+
+sendWithCustomExpect : (Json.Decode.Decoder a -> Http.Expect msg) -> Request a -> Cmd msg
+sendWithCustomExpect expect (Request req) =
     Http.request
         { method = req.method
         , headers = req.headers
         , url = Url.Builder.crossOrigin req.basePath req.pathParams req.queryParams
         , body = req.body
-        , expect = expectJson mapError toMsg req.decoder
+        , expect = expect req.decoder
         , timeout = req.timeout
         , tracker = req.tracker
         }