Lift restriction of swagger spec delivery from Handler to any Monad

  - By using the ServerT type family we allow custom monads to deliver swagger.json

Author: dmjio

servant-swagger-ui-core/src/Servant/Swagger/UI/Core.hs

@@ -101,16 +101,19 @@ instance (KnownSymbol dir, HasLink api, Link ~ MkLink api Link, IsElem api api)
         proxyApi = Proxy :: Proxy api
 
 swaggerSchemaUIServerImpl
-    :: (Server api ~ Handler Swagger)
+    :: (Monad m, ServerT api m ~ m Swagger)
     => T.Text -> [(FilePath, ByteString)]
-    -> Swagger -> Server (SwaggerSchemaUI' dir api)
+    -> Swagger -> ServerT (SwaggerSchemaUI' dir api) m
 swaggerSchemaUIServerImpl indexTemplate files swagger
   = swaggerSchemaUIServerImpl' indexTemplate files $ return swagger
 
 -- | Use a custom server to serve the Swagger spec source.
 swaggerSchemaUIServerImpl'
-    :: T.Text -> [(FilePath, ByteString)]
-    -> Server api -> Server (SwaggerSchemaUI' dir api)
+    :: Monad m
+    => T.Text
+    -> [(FilePath, ByteString)]
+    -> ServerT api m
+    -> ServerT (SwaggerSchemaUI' dir api) m
 swaggerSchemaUIServerImpl' indexTemplate files server
        = server
     :<|> return (SwaggerUiHtml indexTemplate)

servant-swagger-ui/src/Servant/Swagger/UI.hs

@@ -46,7 +46,9 @@ module Servant.Swagger.UI (
     SwaggerSchemaUI,
     SwaggerSchemaUI',
     swaggerSchemaUIServer,
+    swaggerSchemaUIServerT,
     swaggerSchemaUIServer',
+    swaggerSchemaUIServerT',
 
     -- ** Official swagger ui
     swaggerUiIndexTemplate,
@@ -72,6 +74,19 @@ swaggerSchemaUIServer
 swaggerSchemaUIServer =
     swaggerSchemaUIServerImpl swaggerUiIndexTemplate swaggerUiFiles
 
+-- | Serve Swagger UI on @/dir@ using @api@ as a Swagger spec source.
+--
+-- Generalized to 'ServerT'
+--
+-- @
+-- swaggerSchemaUIServerT :: Swagger -> ServerT (SwaggerSchemaUI schema dir) m
+-- @
+swaggerSchemaUIServerT
+    :: (Monad m, ServerT api m ~ m Swagger)
+    => Swagger -> ServerT (SwaggerSchemaUI' dir api) m
+swaggerSchemaUIServerT =
+    swaggerSchemaUIServerImpl swaggerUiIndexTemplate swaggerUiFiles
+
 -- | Use a custom server to serve the Swagger spec source.
 --
 -- This allows even more control over how the spec source is served.
@@ -83,6 +98,20 @@ swaggerSchemaUIServer'
 swaggerSchemaUIServer' =
     swaggerSchemaUIServerImpl' swaggerUiIndexTemplate swaggerUiFiles
 
+-- | Use a custom server to serve the Swagger spec source.
+--
+-- This allows even more control over how the spec source is served.
+-- It allows, for instance, serving the spec source with authentication,
+-- customizing the response based on the client or serving a swagger.yaml
+-- instead.
+--
+-- Generalized to 'ServerT'
+--
+swaggerSchemaUIServerT'
+    :: Monad m => ServerT api m -> ServerT (SwaggerSchemaUI' dir api) m
+swaggerSchemaUIServerT' =
+    swaggerSchemaUIServerImpl' swaggerUiIndexTemplate swaggerUiFiles
+
 swaggerUiIndexTemplate :: Text
 swaggerUiIndexTemplate = $(embedText "index.html.tmpl")