Add stringMethodOptionsExtension

This helper function can be used on service methods
to read options, which extend method options by a string.

e.g.

It is possible to read "Some string" for a custom

`my_method_option.bar` message option extension.

See:

https://developers.google.com/protocol-buffers/docs/proto#customoptions

on how to define a custom extension and referencing is by a fieldID.

```
service MyService {

  rpc MyMethod(RequestType) returns(ResponseType) {
    option (my_method_option.bar) = "Some string";
  }
}
```

If `my_method_option.bar` was defined for `fieldID: 50000`
one can reference it using protoc-gen-template like:

```
{{- stringMethodOptionsExtension 50000 .method }}
```
This commit is contained in:
Jan Weitz 2018-02-23 16:55:45 +01:00
parent bb3105a862
commit 6765ff04eb

View File

@ -101,37 +101,38 @@ var ProtoHelpersFuncMap = template.FuncMap{
}
return slice.Index(int(i)).Interface()
},
"snakeCase": xstrings.ToSnakeCase,
"getProtoFile": getProtoFile,
"getMessageType": getMessageType,
"getEnumValue": getEnumValue,
"isFieldMessage": isFieldMessage,
"isFieldMessageTimeStamp": isFieldMessageTimeStamp,
"isFieldRepeated": isFieldRepeated,
"haskellType": haskellType,
"goType": goType,
"goZeroValue": goZeroValue,
"goTypeWithPackage": goTypeWithPackage,
"jsType": jsType,
"jsSuffixReserved": jsSuffixReservedKeyword,
"namespacedFlowType": namespacedFlowType,
"httpVerb": httpVerb,
"httpPath": httpPath,
"httpPathsAdditionalBindings": httpPathsAdditionalBindings,
"httpBody": httpBody,
"shortType": shortType,
"urlHasVarsFromMessage": urlHasVarsFromMessage,
"lowerGoNormalize": lowerGoNormalize,
"goNormalize": goNormalize,
"leadingComment": leadingComment,
"trailingComment": trailingComment,
"leadingDetachedComments": leadingDetachedComments,
"stringFieldExtension": stringFieldExtension,
"boolFieldExtension": boolFieldExtension,
"isFieldMap": isFieldMap,
"fieldMapKeyType": fieldMapKeyType,
"fieldMapValueType": fieldMapValueType,
"replaceDict": replaceDict,
"snakeCase": xstrings.ToSnakeCase,
"getProtoFile": getProtoFile,
"getMessageType": getMessageType,
"getEnumValue": getEnumValue,
"isFieldMessage": isFieldMessage,
"isFieldMessageTimeStamp": isFieldMessageTimeStamp,
"isFieldRepeated": isFieldRepeated,
"haskellType": haskellType,
"goType": goType,
"goZeroValue": goZeroValue,
"goTypeWithPackage": goTypeWithPackage,
"jsType": jsType,
"jsSuffixReserved": jsSuffixReservedKeyword,
"namespacedFlowType": namespacedFlowType,
"httpVerb": httpVerb,
"httpPath": httpPath,
"httpPathsAdditionalBindings": httpPathsAdditionalBindings,
"httpBody": httpBody,
"shortType": shortType,
"urlHasVarsFromMessage": urlHasVarsFromMessage,
"lowerGoNormalize": lowerGoNormalize,
"goNormalize": goNormalize,
"leadingComment": leadingComment,
"trailingComment": trailingComment,
"leadingDetachedComments": leadingDetachedComments,
"stringFieldExtension": stringFieldExtension,
"stringMethodOptionsExtension": stringMethodOptionsExtension,
"boolFieldExtension": boolFieldExtension,
"isFieldMap": isFieldMap,
"fieldMapKeyType": fieldMapKeyType,
"fieldMapValueType": fieldMapValueType,
"replaceDict": replaceDict,
}
var pathMap map[interface{}]*descriptor.SourceCodeInfo_Location
@ -234,6 +235,46 @@ func leadingDetachedComments(i interface{}) []string {
return loc.GetLeadingDetachedComments()
}
// stringMethodOptionsExtension extracts method options of a string type.
// To define your own extensions see:
// https://developers.google.com/protocol-buffers/docs/proto#customoptions
// Typically the fieldID of private extensions should be in the range:
// 50000-99999
func stringMethodOptionsExtension(fieldID int32, f *descriptor.MethodDescriptorProto) string {
if f == nil {
return ""
}
if f.Options == nil {
return ""
}
var extendedType *descriptor.MethodOptions
var extensionType *string
eds := proto.RegisteredExtensions(f.Options)
if eds[fieldID] == nil {
ed := &proto.ExtensionDesc{
ExtendedType: extendedType,
ExtensionType: extensionType,
Field: fieldID,
Tag: fmt.Sprintf("bytes,%d", fieldID),
}
proto.RegisterExtension(ed)
eds = proto.RegisteredExtensions(f.Options)
}
ext, err := proto.GetExtension(f.Options, eds[fieldID])
if err != nil {
return ""
}
str, ok := ext.(*string)
if !ok {
return ""
}
return *str
}
func stringFieldExtension(fieldID int32, f *descriptor.FieldDescriptorProto) string {
if f == nil {
return ""