This question already has answers here:
Missing type in composite literal
(3 answers)
Closed 3 years ago.
func send_msg(msg string, user string) {
url := "https://test.com/"
token := "Bearer " + get_token()
header := req.Header{
"Content-Type": "application/json",
"Authorization": token,
}
// this string param can not use variable user and msg.
// param := `{
// "email": "jjjj#gmail.com",
// "msg_type": "text",
// "content": { "text": "aaaaaaaaaaaaa" }
// }`
// this req.Param param error：missing type in composite literal
param := req.Param{
"email": user,
"msg_type": "text",
"content": { "text" : msg },
}
r,_ := req.Post(url, header, param)
resp := r.String()
log.Println(resp)
}
This req.Param param error：missing type in composite literal
This string param can not use variable user and msg.
How can I use variable param?
Assuming you are using "net/http", The Post function expects url, content-type and body in that order. Link : net/http#post
Thus, for your particular case, it should look something like this
url := "https://test.com/"
contentType := "application/json"
param := []byte(`{"email": user, "msg_type": "text","content": { "text" : "msg" }, }`)
resp, err := http.Post(url, contentType, bytes.NewBuffer(param))
defer resp.Body.Close()
if err != nil {
//handle error
} else {
body, _ := ioutil.ReadAll(resp.Body)
log.Println(body)
}
If you want to add custom headers, you may use newRequest which gives you req and then you can add or set custom headers .
req.Headers.Set(existingHeaderWithNewValue)
req.Headers.Add(customHeader)
Related
EDIT
This is the working code incase someone finds it useful. The title to this question was originally
"How to parse a list fo dicts in golang".
This is title is incorrect because I was referencing terms I'm familiar with in python.
package main
import (
"encoding/json"
"fmt"
"io/ioutil"
"log"
"net/http"
)
//Regional Strut
type Region []struct {
Region string `json:"region"`
Description string `json:"Description"`
ID int `json:"Id"`
Name string `json:"Name"`
Status int `json:"Status"`
Nodes []struct {
NodeID int `json:"NodeId"`
Code string `json:"Code"`
Continent string `json:"Continent"`
City string `json:"City"`
} `json:"Nodes"`
}
//working request and response
func main() {
url := "https://api.geo.com"
// Create a Bearer string by appending string access token
var bearer = "TOK:" + "TOKEN"
// Create a new request using http
req, err := http.NewRequest("GET", url, nil)
// add authorization header to the req
req.Header.Add("Authorization", bearer)
//This is what the response from the API looks like
//regionJson := `[{"region":"GEO:ABC","Description":"ABCLand","Id":1,"Name":"ABCLand [GEO-ABC]","Status":1,"Nodes":[{"NodeId":17,"Code":"LAX","Continent":"North America","City":"Los Angeles"},{"NodeId":18,"Code":"LBC","Continent":"North America","City":"Long Beach"}]},{"region":"GEO:DEF","Description":"DEFLand","Id":2,"Name":"DEFLand","Status":1,"Nodes":[{"NodeId":15,"Code":"NRT","Continent":"Asia","City":"Narita"},{"NodeId":31,"Code":"TYO","Continent":"Asia","City":"Tokyo"}]}]`
//Send req using http Client
client := &http.Client{}
resp, err := client.Do(req)
if err != nil {
log.Println("Error on response.\n[ERROR] -", err)
}
defer resp.Body.Close()
body, err := ioutil.ReadAll(resp.Body)
if err != nil {
log.Println("Error while reading the response bytes:", err)
}
var regions []Region
json.Unmarshal([]byte(body), ®ions)
fmt.Printf("Regions: %+v", regions)
}
Have a look at this playground example for some pointers.
Here's the code:
package main
import (
"encoding/json"
"log"
)
func main() {
b := []byte(`
[
{"key": "value", "key2": "value2"},
{"key": "value", "key2": "value2"}
]`)
var mm []map[string]string
if err := json.Unmarshal(b, &mm); err != nil {
log.Fatal(err)
}
for _, m := range mm {
for k, v := range m {
log.Printf("%s [%s]", k, v)
}
}
}
I reformatted the API response you included because it is not valid JSON.
In Go it's necessary to define types to match the JSON schema.
I don't know why the API appends % to the end of the result so I've ignored that. If it is included, you will need to trim the results from the file before unmarshaling.
What you get from the unmarshaling is a slice of maps. Then, you can iterate over the slice to get each map and then iterate over each map to extract the keys and values.
Update
In your updated question, you include a different JSON schema and this change must be reflect in the Go code by update the types. There are some other errors in your code. Per my comment, I encourage you to spend some time learning the language.
package main
import (
"bytes"
"encoding/json"
"io/ioutil"
"log"
)
// Response is a type that represents the API response
type Response []Record
// Record is a type that represents the individual records
// The name Record is arbitrary as it is unnamed in the response
// Golang supports struct tags to map the JSON properties
// e.g. JSON "region" maps to a Golang field "Region"
type Record struct {
Region string `json:"region"`
Description string `json:"description"`
ID int `json:"id"`
Nodes []Node
}
type Node struct {
NodeID int `json:"NodeId`
Code string `json:"Code"`
}
func main() {
// A slice of byte representing your example response
b := []byte(`[{
"region": "GEO:ABC",
"Description": "ABCLand",
"Id": 1,
"Name": "ABCLand [GEO-ABC]",
"Status": 1,
"Nodes": [{
"NodeId": 17,
"Code": "LAX",
"Continent": "North America",
"City": "Los Angeles"
}, {
"NodeId": 18,
"Code": "LBC",
"Continent": "North America",
"City": "Long Beach"
}]
}, {
"region": "GEO:DEF",
"Description": "DEFLand",
"Id": 2,
"Name": "DEFLand",
"Status": 1,
"Nodes": [{
"NodeId": 15,
"Code": "NRT",
"Continent": "Asia",
"City": "Narita"
}, {
"NodeId": 31,
"Code": "TYO",
"Continent": "Asia",
"City": "Tokyo"
}]
}]`)
// To more closely match your code, create a Reader
rdr := bytes.NewReader(b)
// This matches your code, read from the Reader
body, err := ioutil.ReadAll(rdr)
if err != nil {
// Use Printf to format strings
log.Printf("Error while reading the response bytes\n%s", err)
}
// Initialize a variable of type Response
resp := &Response{}
// Try unmarshaling the body into it
if err := json.Unmarshal(body, resp); err != nil {
log.Fatal(err)
}
// Print the result
log.Printf("%+v", resp)
}
Requirements
Two services:
Server - for writing blog posts to MongoDB
Client - sends request to the first service
The blog post has title of type string, and content which is a dynamic type - can be any JSON value.
Protobuf
syntax = "proto3";
package blog;
option go_package = "blogpb";
import "google/protobuf/struct.proto";
message Blog {
string id = 1;
string title = 2;
google.protobuf.Value content = 3;
}
message CreateBlogRequest {
Blog blog = 1;
}
message CreateBlogResponse {
Blog blog = 1;
}
service BlogService {
rpc CreateBlog (CreateBlogRequest) returns (CreateBlogResponse);
}
Let's start with protobuf message, which meats requirements - string for title and any JSON value for content.
Client
package main
import (...)
func main() {
cc, _ := grpc.Dial("localhost:50051", grpc.WithInsecure())
defer cc.Close()
c := blogpb.NewBlogServiceClient(cc)
var blog blogpb.Blog
json.Unmarshal([]byte(`{"title": "First example", "content": "string"}`), &blog)
c.CreateBlog(context.Background(), &blogpb.CreateBlogRequest{Blog: &blog})
json.Unmarshal([]byte(`{"title": "Second example", "content": {"foo": "bar"}}`), &blog)
c.CreateBlog(context.Background(), &blogpb.CreateBlogRequest{Blog: &blog})
}
The client sends two requests to the server - one with content having string type, and other with the object. No errors here.
Server
package main
import (...)
var collection *mongo.Collection
type server struct {
}
type blogItem struct {
ID primitive.ObjectID `bson:"_id,omitempty"`
Title string `bson:"title"`
Content *_struct.Value `bson:"content"`
}
func (*server) CreateBlog(ctx context.Context, req *blogpb.CreateBlogRequest) (*blogpb.CreateBlogResponse, error) {
blog := req.GetBlog()
data := blogItem{
Title: blog.GetTitle(),
Content: blog.GetContent(),
}
// TODO: convert "data" or "data.Content" to something that could be BSON encoded..
res, err := collection.InsertOne(context.Background(), data)
if err != nil {
log.Fatal(err)
}
oid, _ := res.InsertedID.(primitive.ObjectID)
return &blogpb.CreateBlogResponse{
Blog: &blogpb.Blog{
Id: oid.Hex(),
Title: blog.GetTitle(),
Content: blog.GetContent(),
},
}, nil
}
func main() {
client, _ := mongo.NewClient(options.Client().ApplyURI("mongodb://localhost:27017"))
client.Connect(context.TODO())
collection = client.Database("mydb").Collection("blog")
lis, _ := net.Listen("tcp", "0.0.0.0:50051")
s := grpc.NewServer([]grpc.ServerOption{}...)
blogpb.RegisterBlogServiceServer(s, &server{})
reflection.Register(s)
go func() { s.Serve(lis) }()
ch := make(chan os.Signal, 1)
signal.Notify(ch, os.Interrupt)
<-ch
client.Disconnect(context.TODO())
lis.Close()
s.Stop()
}
And here I get:
cannot transform type main.blogItem to a BSON Document: no encoder
found for structpb.isValue_Kind
What do I expect? To see the exact value of content in MongoDB, something like this:
{ "_id" : ObjectId("5e5f6f75d2679d058eb9ef79"), "title" : "Second example", "content": "string" }
{ "_id" : ObjectId("5e5f6f75d2679d058eb9ef78"), "title" : "First example", "content": { "foo": "bar" } }
I guess I need to transform data.Content in the line where I added TODO:...
I can create github repo with this example if that could help.
So as suggested by #nguyenhoai890 in the comment I managed to fix it using jsonpb lib - first MarshalToString to covert from structpb to string(json) and then json.Unmarshal to convert from string(json) to interface{} which is supported by BSON. Also I had to fix a Client to correctly unmarshal from string to protobuf.
Client
func main() {
cc, _ := grpc.Dial("localhost:50051", grpc.WithInsecure())
defer cc.Close()
c := blogpb.NewBlogServiceClient(cc)
var blog blogpb.Blog
jsonpb.UnmarshalString(`{"title": "Second example", "content": {"foo": "bar"}}`, &blog)
c.CreateBlog(context.Background(), &blogpb.CreateBlogRequest{Blog: &blog})
jsonpb.UnmarshalString(`{"title": "Second example", "content": "stirngas"}`, &blog)
c.CreateBlog(context.Background(), &blogpb.CreateBlogRequest{Blog: &blog})
}
Server
type blogItem struct {
ID primitive.ObjectID `bson:"_id,omitempty"`
Title string `bson:"title"`
Content interface{} `bson:"content"`
}
func (*server) CreateBlog(ctx context.Context, req *blogpb.CreateBlogRequest) (*blogpb.CreateBlogResponse, error) {
blog := req.GetBlog()
contentString, err := new(jsonpb.Marshaler).MarshalToString(blog.GetContent())
if err != nil {
log.Fatal(err)
}
var contentInterface interface{}
json.Unmarshal([]byte(contentString), &contentInterface)
data := blogItem{
Title: blog.GetTitle(),
Content: contentInterface,
}
res, err := collection.InsertOne(context.Background(), data)
if err != nil {
log.Fatal(err)
}
oid, _ := res.InsertedID.(primitive.ObjectID)
return &blogpb.CreateBlogResponse{
Blog: &blogpb.Blog{
Id: oid.Hex(),
Title: blog.GetTitle(),
Content: blog.GetContent(),
},
}, nil
}
I'm a bit new to Go and I'm having trouble converting a response object from an API call into different structures based on the request type
Essentially, I have one func which sends out a request
func (fpc *FPClient) request(path string, method string, params interface{}, Token string, response interface{}) *dto.AppError {
client := &http.Client{
Timeout: time.Second * 15,
}
requestBody, err := json.Marshal(params)
if err != nil {
//
}
req, _ := http.NewRequest(method, path, bytes.NewBuffer(requestBody))
req.Header.Set("Content-Type", "application/json")
req.Header.Set("Cookie", fmt.Sprintf("cookie=%s;", Token))
req.SetBasicAuth(fpc.username, fpc.password)
resp, err := client.Do(req)
if err != nil {
//
}
body, err := ioutil.ReadAll(resp.Body)
if err != nil {
//
}
if FPErr := fpc.processErrors(resp, body); FPerr != nil {
return FPErr
}
responseData := FPApiSuccess{Head: response, Body: response}
if err := json.Unmarshal(body, &responseData); err != nil {
//
}
fmt.Printf("\n\n client Response : \n %+v \n", responseData.Body)
return nil
}
The struct for FPApiSuccess is:
type FPApiSuccess struct {
Body interface{} `json:"body"`
Head interface{} `json:"head"`
}
Right now, there are 2 calling functions and the API response expected is a bit different for both
Both API responses have the below structure
{
"head": {},
"body": {}
}
However, the nested details in each key is different based on the API used.
I want to capture the head and body keys in a struct argument I give and send it back to the calling function. The response argument in the request function is a different struct type based on the calling function.
I'm unable to get this to work - I'm only getting back a blank struct from the request function. This is the fmt.PrintF log
client Response :
&{Body:{BOrderID:0 CC: Exch: EOID: Type: Local:0 Message: } Head:{ResponseCode: Status: StatusDescription:}}
This is an empty struct - ideally, it should be populated with the values retrieved from the API.
For reference, heres the struct passed as an argument as response in the request function:
type FPApiResponse struct {
Body FPBodyResponse `json:"body"`
Head FPHeadResponse `json:"head"`
}
type FPHeadResponse struct {
ResponseCode string `json:"responseCode"`
Status string `json:"status"`
StatusDescription string `json:"statusDescription"`
}
type FPBodyResponse struct {
BOrderID int `json:"BOrderID"`
CC string `json:"CC"`
Exch string `json:"Exch"`
EOID string `json:"EOID"`
Type string `json:"Type"`
Local int `json:"Local"`
Message string `json:"Message"`
}
Update
So I did this; instead of
responseData := FPApiSuccess{Head: response, Body: response}
I did this
responseData := fivePaisaApiSuccess{}
So now, I get the below in console
Client Response :
{Body:map[BOrderID:0 CC:52715111 Type:D Local:0 Message:Invalid Session ] Head:map[responseCode:5POrdReq status:0 statusDescription:Success]}
So essentially, this works, but the calling function doesn't seem to get the proper response:
Here's the calling function
func (fpc *FPClient) PlaceOrder(orderParams dto.OrderBodyParams, variety string, Token string) (string, *dto.AppError) {
var result FPApiResponse
headParams := dto.FFPOrderHeadParams{
//
}
FPOrderParams := dto.FPOrderParams{
//
}
FPErr := fpc.request(FPURL+FPPlaceOrder, http.MethodPost, FPOrderParams, brokerAccessToken, &result)
if FPErr != nil {
return "", FPErr
}
fmt.Printf("\n\n Client result : \n %+v \n", result)
if result.Head.Status != "0" {
//
}
if result.Body.Status != 0 {
//
}
return strconv.Itoa(result.Body.Broker), nil
}
The result value is blank:
{Body:{BOId:0 CC: Exch: Type: Local:0 Message: Status:0} Head:{ResponseCode: Status: StatusDescription:}}
I don't understand, this pointer is getting populated in the request function
Here's the struct I'm passing to the request:
type FPApiResponse struct {
Body FPBodyResponse `json:"body"`
Head FPHeadResponse `json:"head"`
}
This question already has an answer here:
Unmarshalling json in golang
(1 answer)
Closed 4 years ago.
I have an API which accepts a request body like this:
The content-type is application/json.
{
"firstname": "foo",
"surname": "bar",
"age": 10,
"group":"test"
}
The request goes through when I use a client like Postman.
However, the same request fails from Go:
type Student struct {
firstname string
surname string
age int
group string
}
student:= Student{"foo", "bar", 10, "test"}
b, err := json.Marshal(student)
rest := restCall("POST", "http://api", b, "xyz123")
func restCall(method string, url string, body []byte, token string) {
req, _ := http.NewRequest(method, url, bytes.NewReader(body))
req.Header.Add("Authorization", token)
req.Header.Add("content-type", "application/json")
res, _ := http.DefaultClient.Do(req)
defer res.Body.Close()
}
I get an internal HTTP 500 error stating :
Mandatory parameter 'group' is missing.
But, I did pass it as you can see from my code.
Your code has several issues:
1. Structure must have public fields and fields should be tagged. Then it will be serialized properly:
type Student struct {
Firstname string `json:"firstname"`
Surname string `json: "surname"`
Age int . `json: "age"`
Group string `json: "group"`
}
2. Never ignore errors returned by method call. So you will not miss issues in your code:
b, err := json.Marshal(student)
if err != nil {
fmt.Println(err)
}
And the same after calls of NewRequest and DefaultClient.Do
This question already has an answer here:
Return custom error message from struct tag validation
(1 answer)
Closed 1 year ago.
For example I've got the following struct
type Address struct {
City string `json:"city" binding:"required"`
AddressLine string `json:"address_line" binding:"required"`
}
and I've got the following function to handle request from users
func AddressCreate(c *gin.Context) {
var address Address
if err := c.BindJSON(&address); err == nil {
// if everything is good save to database
// and return success message
db.Create(&address)
c.JSON(http.StatusOK, gin.H {"status":"success"})
} else {
c.JSON(http.StatusBadRequest, err)
}
}
Expected behavior is to return JSON, formatted this way
[
{
"city":"required"
}
{
"address_line":"required"
}
]
But I'm getting an error formatted like this
"Address.City": {
"FieldNamespace": "Address.City",
"NameNamespace": "City",
"Field": "City",
"Name": "City",
"Tag": "required",
"ActualTag": "required",
"Kind": 24,
"Type": {},
"Param": "",
"Value": ""
},
"Address.AddressLine": {
"FieldNamespace": "AddressLine",
"NameNamespace": "AddressLine",
"Field": "AddressLine",
"Name": "AddressLine",
"Tag": "required",
"ActualTag": "required",
"Kind": 24,
"Type": {},
"Param": "",
"Value": ""
}
What I tried:
I created function which casts error to ValidationErrors and iterates through all FieldError's in it
func ListOfErrors(e error) []map[string]string {
ve := e.(validator.ValidationErrors)
InvalidFields := make([]map[string]string, 0)
for _, e := range ve {
errors := map[string]string{}
// field := reflect.TypeOf(e.NameNamespace)
errors[e.Name] = e.Tag
InvalidFields = append(InvalidFields, errors)
}
return InvalidFields
}
The output look's much better
[
{
"City":"required"
},
{
"AddressLine":"required"
}
]
But I cannot solve the problem with the name of the fields. I cannot swap Name into name which I noted in structs tag json:"city". So my question is did I choose correct way to solve the problem if the answer is yes how to get structs JSON tag for field?
If you want it to be same as defined in your json tag, then you should use reflection to pull that tag from your data type.
I don't have your libraries, so can't compile and check it. But I believe what you are after should go along those lines:
func ListOfErrors(address *Address, e error) []map[string]string {
ve := e.(validator.ValidationErrors)
InvalidFields := make([]map[string]string, 0)
for _, e := range ve {
errors := map[string]string{}
// field := reflect.TypeOf(e.NameNamespace)
field, _ := reflect.TypeOf(address).Elem().FieldByName(e.Name)
jsonTag := string(field.Tag.Get("json"))
errors[jsonTag] = e.Tag
InvalidFields = append(InvalidFields, errors)
}
return InvalidFields
}
Note that it is a bit contrived as type of address parameter is essentially known. So, not strictly required as a function parameter. But you can change address *Address to address interface{} and use it for other types too.
Disclaimer: I skipped error checking for brevity, but you certainly should check for errors in your code (e.g. no such field error or no json tag on that field).
You can use ToSnake to snake case the names:
import (
"unicode"
)
// ToSnake convert the given string to snake case following the Golang format:
// acronyms are converted to lower-case and preceded by an underscore.
func ToSnake(in string) string {
runes := []rune(in)
length := len(runes)
var out []rune
for i := 0; i < length; i++ {
if i > 0 && unicode.IsUpper(runes[i]) && ((i+1 < length && unicode.IsLower(runes[i+1])) || unicode.IsLower(runes[i-1])) {
out = append(out, '_')
}
out = append(out, unicode.ToLower(runes[i]))
}
return string(out)
}
func ListOfErrors(e error) []map[string]string {
ve := e.(validator.ValidationErrors)
invalidFields := make([]map[string]string, 0)
for _, e := range ve {
errors := map[string]string{}
errors[ToSnake(e.Name)] = e.Tag
invalidFields = append(InvalidFields, errors)
}
return invalidFields
}