write query parameters to swagger definition

examples/clients/abe/ABitOfEverythingServiceApi.go

@@ -354,10 +354,11 @@ func (a ABitOfEverythingServiceApi) Echo (value string) (SubStringMessage, error
 /**
  * 
  * 
+ * @param value 
  * @return SubStringMessage
  */
-//func (a ABitOfEverythingServiceApi) Echo_1 () (SubStringMessage, error) {
-func (a ABitOfEverythingServiceApi) Echo_1 () (SubStringMessage, error) {
+//func (a ABitOfEverythingServiceApi) Echo_1 (value string) (SubStringMessage, error) {
+func (a ABitOfEverythingServiceApi) Echo_1 (value string) (SubStringMessage, error) {
 
     _sling := sling.New().Get(a.basePath)
 
@@ -366,6 +367,11 @@ func (a ABitOfEverythingServiceApi) Echo_1 () (SubStringMessage, error) {
 
     _sling = _sling.Path(path)
 
+    type QueryParams struct {
+        value    string `url:"value,omitempty"`
+
+}
+    _sling = _sling.QueryStruct(&QueryParams{ value: value })
     // accept header
     accepts := []string { "application/json" }
     for key := range accepts {

examples/examplepb/a_bit_of_everything.swagger.json

@@ -312,6 +312,14 @@
             }
           }
         },
+        "parameters": [
+          {
+            "name": "value",
+            "in": "query",
+            "required": false,
+            "type": "string"
+          }
+        ],
         "tags": [
           "ABitOfEverythingService"
         ]

protoc-gen-swagger/genswagger/template.go

@@ -13,6 +13,49 @@ import (
 	"github.com/grpc-ecosystem/grpc-gateway/protoc-gen-grpc-gateway/descriptor"
 )
 
+// messageToQueryParameters converts a message to a list of swagger query parameters.
+func messageToQueryParameters(message *descriptor.Message, reg *descriptor.Registry, pathParams []descriptor.Parameter) ([]swaggerParameterObject, error) {
+	var parameters []swaggerParameterObject
+	var addParameterWithPrefix func(string, *descriptor.Field) error
+	addParameterWithPrefix = func(prefix string, field *descriptor.Field) error {
+		// make sure the parameter is not already listed as a path parameter
+		for _, pathParam := range pathParams {
+			if pathParam.Target == field {
+				return nil
+			}
+		}
+		schema := schemaOfField(field, reg)
+		if schema.Type != "" {
+			// basic type, add a basic query parameter
+			parameters = append(parameters, swaggerParameterObject{
+				Name:        prefix + field.GetName(),
+				Description: schema.Description,
+				In:          "query",
+				Type:        schema.Type,
+			})
+			return nil
+		}
+
+		// nested type, recurse
+		msg, err := reg.LookupMsg("", field.GetTypeName())
+		if err != nil {
+			return fmt.Errorf("unknown message type %s", field.GetTypeName())
+		}
+		for _, nestedField := range msg.Fields {
+			if err := addParameterWithPrefix(field.GetName()+".", nestedField); err != nil {
+				return err
+			}
+		}
+		return nil
+	}
+	for _, field := range message.Fields {
+		if err := addParameterWithPrefix("", field); err != nil {
+			return parameters, err
+		}
+	}
+	return parameters, nil
+}
+
 // findServicesMessagesAndEnumerations discovers all messages and enums defined in the RPC methods of the service.
 func findServicesMessagesAndEnumerations(s []*descriptor.Service, reg *descriptor.Registry, m messageMap, e enumMap) {
 	for _, svc := range s {
@@ -381,6 +424,13 @@ func renderServices(services []*descriptor.Service, paths swaggerPathsObject, re
 							},
 						},
 					})
+				} else if b.HTTPMethod == "GET" {
+					// add the parameters to the query string
+					queryParams, err := messageToQueryParameters(meth.RequestType, reg, b.PathParams)
+					if err != nil {
+						return err
+					}
+					parameters = append(parameters, queryParams...)
 				}
 
 				pathItemObject, ok := paths[templateToSwaggerPath(b.PathTmpl.Template)]

protoc-gen-swagger/genswagger/template_test.go

@@ -7,6 +7,7 @@ import (
 
 	"github.com/golang/protobuf/proto"
 	protodescriptor "github.com/golang/protobuf/protoc-gen-go/descriptor"
+	plugin "github.com/golang/protobuf/protoc-gen-go/plugin"
 	"github.com/grpc-ecosystem/grpc-gateway/protoc-gen-grpc-gateway/descriptor"
 	"github.com/grpc-ecosystem/grpc-gateway/protoc-gen-grpc-gateway/httprule"
 )
@@ -30,6 +31,123 @@ func crossLinkFixture(f *descriptor.File) *descriptor.File {
 	return f
 }
 
+func TestMessageToQueryParameters(t *testing.T) {
+	type test struct {
+		MsgDescs []*protodescriptor.DescriptorProto
+		Message  string
+		Params   []swaggerParameterObject
+	}
+
+	tests := []test{
+		{
+			MsgDescs: []*protodescriptor.DescriptorProto{
+				&protodescriptor.DescriptorProto{
+					Name: proto.String("ExampleMessage"),
+					Field: []*protodescriptor.FieldDescriptorProto{
+						{
+							Name:   proto.String("a"),
+							Type:   protodescriptor.FieldDescriptorProto_TYPE_STRING.Enum(),
+							Number: proto.Int32(1),
+						},
+						{
+							Name:   proto.String("b"),
+							Type:   protodescriptor.FieldDescriptorProto_TYPE_DOUBLE.Enum(),
+							Number: proto.Int32(2),
+						},
+					},
+				},
+			},
+			Message: "ExampleMessage",
+			Params: []swaggerParameterObject{
+				swaggerParameterObject{
+					Name:     "a",
+					In:       "query",
+					Required: false,
+					Type:     "string",
+				},
+				swaggerParameterObject{
+					Name:     "b",
+					In:       "query",
+					Required: false,
+					Type:     "number",
+				},
+			},
+		},
+		{
+			MsgDescs: []*protodescriptor.DescriptorProto{
+				&protodescriptor.DescriptorProto{
+					Name: proto.String("ExampleMessage"),
+					Field: []*protodescriptor.FieldDescriptorProto{
+						{
+							Name:     proto.String("nested"),
+							Type:     protodescriptor.FieldDescriptorProto_TYPE_MESSAGE.Enum(),
+							TypeName: proto.String(".example.Nested"),
+							Number:   proto.Int32(1),
+						},
+					},
+				},
+				&protodescriptor.DescriptorProto{
+					Name: proto.String("Nested"),
+					Field: []*protodescriptor.FieldDescriptorProto{
+						{
+							Name:   proto.String("a"),
+							Type:   protodescriptor.FieldDescriptorProto_TYPE_STRING.Enum(),
+							Number: proto.Int32(1),
+						},
+					},
+				},
+			},
+			Message: "ExampleMessage",
+			Params: []swaggerParameterObject{
+				swaggerParameterObject{
+					Name:     "nested.a",
+					In:       "query",
+					Required: false,
+					Type:     "string",
+				},
+			},
+		},
+	}
+
+	for _, test := range tests {
+		reg := descriptor.NewRegistry()
+		msgs := []*descriptor.Message{}
+		for _, msgdesc := range test.MsgDescs {
+			msgs = append(msgs, &descriptor.Message{DescriptorProto: msgdesc})
+		}
+		file := descriptor.File{
+			FileDescriptorProto: &protodescriptor.FileDescriptorProto{
+				SourceCodeInfo: &protodescriptor.SourceCodeInfo{},
+				Name:           proto.String("example.proto"),
+				Package:        proto.String("example"),
+				Dependency:     []string{},
+				MessageType:    test.MsgDescs,
+				Service:        []*protodescriptor.ServiceDescriptorProto{},
+			},
+			GoPkg: descriptor.GoPackage{
+				Path: "example.com/path/to/example/example.pb",
+				Name: "example_pb",
+			},
+			Messages: msgs,
+		}
+		reg.Load(&plugin.CodeGeneratorRequest{
+			ProtoFile: []*protodescriptor.FileDescriptorProto{file.FileDescriptorProto},
+		})
+
+		message, err := reg.LookupMsg("", ".example."+test.Message)
+		if err != nil {
+			t.Fatalf("failed to lookup message: %s", err)
+		}
+		params, err := messageToQueryParameters(message, reg, []descriptor.Parameter{})
+		if err != nil {
+			t.Fatalf("failed to convert message to query parameters: %s", err)
+		}
+		if !reflect.DeepEqual(params, test.Params) {
+			t.Errorf("expected %v, got %v", test.Params, params)
+		}
+	}
+}
+
 func TestApplyTemplateSimple(t *testing.T) {
 	msgdesc := &protodescriptor.DescriptorProto{
 		Name: proto.String("ExampleMessage"),