Add example for contentType encoder/decoder (#224)

Author: vearutop

_examples/advanced-generic-openapi31/_testdata/openapi.json

@@ -655,6 +655,29 @@
     "x-forbid-unknown-query":true
    }
   },
+  "/raw-body":{
+   "parameters":[
+    {
+     "name":"X-Umbrella-Header","in":"header","description":"This request header is supported in all operations.",
+     "schema":{"type":"string"}
+    }
+   ],
+   "post":{
+    "tags":["Request","Response"],"summary":"Request/response With Raw Body",
+    "description":"The `contentType` tag acts as a discriminator of where to read/write the body.",
+    "operationId":"_examples/advanced-generic-openapi31.rawBody",
+    "requestBody":{"content":{"text/csv":{"schema":{"type":"string"}},"text/plain":{"schema":{"type":"string"}}}},
+    "responses":{
+     "200":{
+      "description":"OK",
+      "content":{
+       "application/json":{"schema":{"type":"string"}},"text/csv":{"schema":{"type":"string"}},
+       "text/plain":{"schema":{"type":"string"}}
+      }
+     }
+    }
+   }
+  },
   "/req-resp-mapping":{
    "parameters":[
     {

_examples/advanced-generic-openapi31/raw_body.go

@@ -0,0 +1,25 @@
+package main
+
+import (
+	"context"
+	"github.com/swaggest/usecase"
+)
+
+func rawBody() usecase.Interactor {
+	type rawBody struct {
+		TextBody string `contentType:"text/plain"`
+		CSVBody  string `contentType:"text/csv"`
+	}
+
+	u := usecase.NewInteractor(func(ctx context.Context, input rawBody, output *rawBody) error {
+		*output = input
+
+		return nil
+	})
+
+	u.SetTitle("Request/response With Raw Body")
+	u.SetDescription("The `contentType` tag acts as a discriminator of where to read/write the body.")
+	u.SetTags("Request", "Response")
+
+	return u
+}

_examples/advanced-generic-openapi31/router.go

@@ -154,6 +154,7 @@ func NewRouter() *web.Service {
 
 	s.Get("/query-object", queryObject())
 	s.Post("/form", form())
+	s.Post("/raw-body", rawBody())
 
 	s.Post("/file-upload", fileUploader())
 	s.Post("/file-multi-upload", fileMultiUploader())