Im using postman to post data and in the body Im putting some simple json
Request Body
{
"order":"1",
"Name":"ts1"
}
I need to transfer the data to json and I try like following,
and I wasnt able to get json, any idea what is missing
router.POST("/user", func(c *gin.Context) {
var f interface{}
//value, _ := c.Request.GetBody()
//fmt.Print(value)
err2 := c.ShouldBindJSON(&f)
if err2 == nil {
err = client.Set("id", f, 0).Err()
if err != nil {
panic(err)
}
}
The f is not a json and Im getting an error, any idea how to make it work?
The error is:
redis: can't marshal map[string]interface {} (implement encoding.BinaryMarshaler)
I use https://github.com/go-redis/redis#quickstart
If I remove the the body and use hard-coded code like this I was able to set the data, it works
json, err := json.Marshal(Orders{
order: "1",
Name: "tst",
})
client.Set("id", json, 0).Err()
If you only want to pass the request body JSON to Redis as a value, then you do not need to bind the JSON to a value. Read the raw JSON from the request body directly and just pass it through:
jsonData, err := ioutil.ReadAll(c.Request.Body)
if err != nil {
// Handle error
}
err = client.Set("id", jsonData, 0).Err()
let's do it with an example. Assume your request body has a user email like this:
{ email: "test#test.com" }
and now you want to get this email on the back-end. first, define a struct like the following:
type EmailRequestBody struct {
Email string
}
Now you can easily bind the email value in your request body to the struct you defined: first, define a variable for your struct and then bind the value:
func ExampleFunction(c *gin.Context) {
var requestBody EmailRequestBody
if err := c.BindJSON(&requestBody); err != nil {
// DO SOMETHING WITH THE ERROR
}
fmt.Println(requestBody.Email)
}
you can easily access the email value and print it out or do whatever you need :
fmt.Println(requestBody.Email)
Or you can use GetRawData() function as:
jsonData, err := c.GetRawData()
if err != nil{
//Handle Error
}
err = client.Set("id", jsonData, 0).Err()
If you want to get json body like other frameworks like express(Nodejs), you can do the following
bodyAsByteArray, _ := ioutil.ReadAll(c.Request.Body)
jsonBody := string(bodyAsByteArray)
Related
I'm currently using gRPC for my API communication. Now I need the value of my request can accept any data type, be it a struct object or just a primitive data type like single integer, string, or boolean. I tried using google.protobuf.Any as below but it doesn't work when I want to marshal and unmarshal it.
message MyRequest {
google.protobuf.Any item = 1; // could be 9, "a string", true, false, {"key": value}, etc.
}
proto-compiled result:
type MyRequest struct {
Item *anypb.Any `protobuf:"bytes,1,opt,name=item,proto3" json:"item,omitempty"`
}
I will marshal the incoming request through gRPC and save it as a JSON string in the database:
bytes, err = json.Marshal(m.request.Item)
if err != nil {
return err
}
itemStr := string(bytes)
But when I want to unmarshal the string back into *anypb.Any by:
func getItem(itemStr string) (structpb.Value, error) {
var item structpb.Value
err := json.Unmarshal([]byte(itemStr), &item)
if err != nil {
return item, err
}
// also I've no idea on how to convert `structpb.Value` to `anypb.Any`
return item, nil
}
It returns an error which seems to be because the struct *anypb.Any doesn't contain any of the fields in my encoded item string. Is there a correct way to solve this problem?
Consider using anypb
In the documentation it shows an example of how to unmarshal it
m := new(foopb.MyMessage)
if err := any.UnmarshalTo(m); err != nil {
... // handle error
}
... // make use of m
I have a string whats contains JSON. I need to transform that string to a JSON object in order to send it in a PUT request. Here is the string I have:
{
"changed": "Jhon",
"created": "Marc",
"date_changed": "2020-10-06T12:51:36Z",
"date_created": "2020-10-06T12:51:36Z",
"title": "\u003ch2\u003e\u003c/h2\u003e"
}
Edit:
This code works for me; the user represents the JSON string upper in the question.
in := []byte(user)
var raw map[string]interface{}
if err := json.Unmarshal(in, &raw); err != nil {
panic(err)
}
fmt.Println(raw["changed"])
out, err := json.Marshal(raw)
if err != nil {
panic(err)
}
Edit 2: this works, too, and is easier
strings.NewReader(user)
OP is asking how to use a string containing a JSON document as a request body.
The body argument to http.NewRequest is an io.Reader. Use the strings.NewReader function to wrap a string with an io.Reader:
req, err := http.NewRequet("PUT", url, strings.NewReader(user))
I am trying to ensure the body of a post request for example contains exact structure of the body and if not ahould throw an error
for example i have the following function
func UpdatePassword(c *fiber.Ctx) error {
type UpdatePasswordData struct {
Password string `json:"password" form:"password"`
NewPassword string `json:"new_password" form:"new_password"`
NewPasswordConfirm string `json:"new_password_confirm" form:"new_password_confirm"`
}
data := UpdatePasswordData{}
if err := c.BodyParser(&data); err != nil {
return err
}
var user models.User
if data.NewPassword != data.NewPasswordConfirm {
c.Status(400)
return c.JSON(fiber.Map{
"message": "passwords do not match",
})
}
email, _ := middlewares.GetUserEmail(c)
newPassword := models.HashPassword(data.NewPassword)
database.DB.Model(&user).Select("Password").Where("email = ?", email).Updates(map[string]interface{}{"Password": newPassword})
return c.JSON(user)
}
the POST request should be looking for body with this structure
{
"password": "oldpassword",
"new_password": "newpassword",
"new_password_confirm": "newpassword",
}
but currently this endpoint accepts body that does not have this exact structure. So how do i enforce the structure in the body of request, so that if structure does not match, i throw an error?
do not like gin, fiber has not builtin validate package
use go-playground/validator
go get github.com/go-playground/validator
example
type UpdatePasswordData struct {
Password string `json:"password" validate:"required,min=8,max=32"`
NewPassword string `json:"new_password" validate:"required,min=8,max=32"`
NewPasswordConfirm string `json:"new_password_confirm" validate:"eqfield=NewPassword"`
}
func UpdatePassword(c *fiber.Ctx) error {
var body UpdatePasswordData
if err := c.BodyParser(&body); err != nil {
return err
}
validate := validator.New()
if err := validate.Struct(body); err != nil {
return err
}
// do others
// get current user, check password == hash(body.password)
// save new passworld
}
or you can see fiber office docs https://docs.gofiber.io/guide/validation#validator-package
We can use struct tag
`validate:"required"`
to ensure that all the mandatory fields are there in the request payload.
Moreover we can validate the fields with the provided tags of the validator package and for additional validations we can implement custom validators and register them like this:
validate := validator.New()
validate.RegisterValidation("password-validator", PasswordValidator)
I have a use case where I have the code as below. I have a request coming in to hit the backend where I need to append data to a map. My question is how do I convert the below type to a []byte to unmarshal?
Any ideas would be appreciated.
type Example struct {
Category string `json:"category"`
Name string `json:"name"`
}
Incoming Postman request json looks like this:
[{"Category":"TestCategory", "Name":"Sample1"}]
but after doing
jsonString Type: []Example
if err := gc.ShouldBindJSON(&jsonString) it looks like [{TestCategory Sample1}] ; how do I convert this to a []byte?
for _, req := range blob{
var jsonString Example
if err := json.Unmarshal([]byte(jsonString), &blob); err != nil { //this does not work
logger.Fatal(err)
}
//I am checking if a key-value is present and appending it to the map
dict := make(map[string][]Example)
dict[req.Category] = append(dict[req.Category], req)
fmt.Println(dict)
if value, ok := dict["TestCategory"]; ok {
fmt.Printf("Found %d\n", value)
} else {
fmt.Println("not found")
}
}
//I was able to test the above logic by declaring the jsonString as a const and it works
There are two directions in which you can move the data:
from JSON to a Go data structure
// This is your payload coming from the request.
jsonStr := `[{"Category":"TestCategory", "Name":"Sample1"}]`
// This is the Go struct that will hold the unmarshalled data.
var examples []Example
err := json.Unmarshal([]byte(jsonStr), &examples)
if err != nil {
log.Fatal(err)
}
fmt.Println("Examples:", examples) // prints "Examples: [{TestCategory Sample1}]"
from a Go data structure to JSON (either string or []byte)
exampleBytes, err := json.Marshal(examples)
if err != nil {
log.Fatal(err)
}
fmt.Println("Example bytes:", string(exampleBytes)) // prints "Example bytes: [{"category":"TestCategory","name":"Sample1"}]"
You should check out "Go by Example" if you haven't already: https://gobyexample.com/json
Looking at your code:
You are looping on blob but instead of using the req you are trying to unmarshal onto the entire blob each time. I'm not sure what you are trying to achieve there but nothing good can come out of changing a struct you're looping over from within the loop.
The request JSON you are listing is an array of JSON objects. You are trying to unmarshal that into a single Example struct. That won't work, you need an array of those.
I'm using the following code to get a response from a server after a post request:
type ResponseFromPost struct {
N_expediente string
Enviar string
}
func main(){
......
res, err := client.Do(req)
if err != nil {
return
}
defer res.Body.Close()
body, err := ioutil.ReadAll(res.Body)
var re ResponseFromPost
err = json.Unmarshal(body, &re)
fmt.Println(re.Enviar);
}
With this I get:
error: &{%!e(string=array) %!e(*reflect.rtype=&{32 2509985895 0 8 8 25 0x608170
[0x7703c0 <nil>] 0x730b80 0x69acb0 0x6116c0 0x7732c0})}
The value sent by the server is:
[{"n_expediente":"9","enviar":"2"}]
How can I use the json variables?
The json is an array of those objects having the strings n_expediente and enviar on each instance. In the Go you'll need an array of your type;
re := []ResponseFromPost{}
err := json.Unmarshal([]byte(`[{"n_expediente":"9","enviar":"2"}]`), &re)
fmt.Println(re[0].Enviar);
Here's an example to show what your model needs to be https://play.golang.org/p/d64Sict4AG
You'll probably want to make some other changes to your code based on that. Like a loop bound by the length of the slice ( for i := range re { print i } ) after the unmarshal and a different name for the type.