helpers.go.tmpl

{{define "helpers"}}
{{ $opts := .Opts -}}

//
// Helpers
//

type method struct  {
	Name string
	Service string
	Annotations map[string]string
}

type contextKey struct {
	name string
}

func (k *contextKey) String() string {
	return "webrpc context value " + k.name
}

var (
{{- if $opts.client}}
	HTTPClientRequestHeadersCtxKey = &contextKey{"HTTPClientRequestHeaders"}
{{- end}}

{{- if $opts.server}}
	HTTPResponseWriterCtxKey = &contextKey{"HTTPResponseWriter"}
{{ end}}
	HTTPRequestCtxKey = &contextKey{"HTTPRequest"}

	ServiceNameCtxKey = &contextKey{"ServiceName"}

	MethodNameCtxKey = &contextKey{"MethodName"}
)

func ServiceNameFromContext(ctx context.Context) string {
	service, _ := ctx.Value(ServiceNameCtxKey).(string)
	return service
}

func MethodNameFromContext(ctx context.Context) string {
	method, _ := ctx.Value(MethodNameCtxKey).(string)
	return method
}

func RequestFromContext(ctx context.Context) *http.Request {
	r, _ := ctx.Value(HTTPRequestCtxKey).(*http.Request)
	return r
}

func MethodCtx(ctx context.Context) (method, bool) {
	req := RequestFromContext(ctx)
	if req == nil {
		return method{}, false
	}

	m, ok := methods[req.URL.Path]
	if !ok {
		return method{}, false
	}

	return m, true
}

{{ if $opts.server}}
func ResponseWriterFromContext(ctx context.Context) http.ResponseWriter {
	w, _ := ctx.Value(HTTPResponseWriterCtxKey).(http.ResponseWriter)
	return w
}
{{- end}}

{{- if and $opts.fixEmptyArrays $opts.server}}

// Copied from https://github.com/golang-cz/nilslice
func initializeNilSlices(obj interface{}) interface{} {
	v := reflect.ValueOf(obj)
	initializeNils(v)

	return obj
}

func initializeNils(v reflect.Value) {
	// Dereference pointer(s).
	for v.Kind() == reflect.Ptr && !v.IsNil() {
		v = v.Elem()
	}

	if v.Kind() == reflect.Slice {
		// Initialize a nil slice.
		if v.IsNil() && v.CanSet() {
			v.Set(reflect.MakeSlice(v.Type(), 0, 0))
			return
		}

		// Recursively iterate over slice items.
		for i := 0; i < v.Len(); i++ {
			item := v.Index(i)
			initializeNils(item)
		}
	}

	// Recursively iterate over struct fields.
	if v.Kind() == reflect.Struct {
		for i := 0; i < v.NumField(); i++ {
			field := v.Field(i)
			initializeNils(field)
		}
	}
}
{{- end -}}

{{- end -}}