go-micro req server.Request and response

graphql-handle-request.go

import (
	"strings"
	"bytes"
	"strconv"
	"context"
	"encoding/json"
	api "github.com/micro/go-api/proto"
)

type GraphqlOperation struct {
	Query     string                 `json:"query"`
	Variables map[string]interface{} `json:"variables"`
	Name      string                 `json:"operationName"`
}

func (s *Session) Graphql(ctx context.Context, req *api.Request, rsp *api.Response) (err error) {
	
	// ... some code
	
	// graphql operation structure
	// https://graphql.org/learn/serving-over-http/#http-methods-headers-and-body
	op := GraphqlOperation{Variables: map[string]interface{}{}}

	// fill graphql operation
	{
		dat := map[string]*api.Pair{}

		switch req.Method {
		case http.MethodGet:
			if req.Get != nil {
				dat = req.Get
			}
		case http.MethodPost:
			// from prepared post data
			if req.Post != nil {
				dat = req.Post
				break
			}
			// set default Content-Type header
			if req.Header == nil {
				log.Warning("graphql request without content-type header - set application/json automatically", ctx)
				req.Header = map[string]*api.Pair{
					"Content-Type": {Key: "Content-Type", Values: []string{"application/json"}},
				}
			}
			// use Content-Type header for parse logic
			hdrContentType, ok := req.Header["Content-Type"]
			if ok {
				hdrContentTypeValue := strings.ToLower(strings.Join(hdrContentType.Values, ""))
				if strings.Contains(hdrContentTypeValue, "application/graphql") {
					op.Query = req.Body
				} else {
					if !strings.Contains(hdrContentTypeValue, "application/json") {
						log.Warning("graphql request with unknown content-type - use application/json automatically", ctx)
					}
					err = json.Unmarshal([]byte(req.Body), &op)
					if err != nil {
						log.Warning("graphql request body with unknown format", log.FmtErr(err), ctx)
						op.Query = req.Body
					}
				}
			}
		}

		if value, ok := dat["query"]; ok {
			op.Query = value.String()
		}
		if value, ok := dat["variables"]; ok {
			if err := json.Unmarshal([]byte(value.String()), &op.Variables); err != nil {
				log.Warning("graphql variables invalid", log.FmtErr(err), ctx)
			}
		}
		if value, ok := dat["operationName"]; ok {
			op.Name = value.String()
		}
	}

	// ... some code with variable "op"
}