I am facing an issue where i have made an api in Go every thing work fine but i am not getting data in postman. When i print the data in logs i am getting the data properly but it is showing blank data in postman.
authorizeModel.go
func GetSkillList() map[string]interface{} {
db := GetDB()
var (
// id int
skillName string
)
type SkillList struct {
name string
}
skillList := SkillList{}
skillArr := []SkillList{}
rows, err := db.Query("select DISTINCT(name) as name from skills where company_id IN ('2') and name != 'Skill Needed' order by name")
if err != nil {
log.Fatal(err)
}
defer rows.Close()
for rows.Next() {
err := rows.Scan(&skillName)
if err != nil {
log.Fatal(err)
}
skillList.name = skillName
skillArr = append(skillArr, skillList)
}
response := u.Message(true, "Skill list retrieved successfully")
response["data"] = skillArr
log.Println(skillArr)
response["authorization"] = false
return response
}
authController.go
var SkillTagList = func(w http.ResponseWriter, r *http.Request) {
resp := models.GetSkillList()
u.Respond(w, resp)
}
routes.go
router.HandleFunc("/api/v1/authorize/skillTagList", controllers.SkillTagList).Methods("POST")
If you see authorizeModel.go i have printed my data in logs i am getting that data successfully in logs. But see the postman screenshot below.
You have to rename name to Name
I'm not sure what is u.Respond(), so I will assume it's a helper function of some framework that you are using, and I will assume u.Respond() is internally using json.Marshal.
If your struct has unexported fields(fields name starting with lowercase letter, in your case name), json.Marshal cannot access those field, and the result won't have name field. That is why you are getting empty objects in JSON.
Related
I'm using range to loop through an array of structs to extract data which will be used as a URL parameter for my API calls. Within this loop, I'm trying to push response data from one struct to another.
I'm able to get everything working, except for moving data from one struct to another, but not entirely sure how to solve for the errors I keep getting. I've tried multiple methods and seem to be stuck in the mud here for something I don't consider to be too hard, until now... In my code I'm using the append method but I'm not so sure that might be the correct way to proceed.
Presenting my code:
models.go
//Here is my existing struct, with populated data that I get from a CSV
type TravelItenaries struct {
Origin string
Destination string
Flight_num string
Origin_latitude string
Origin_longitude string
Destination_latitude string
Destination_longitude string
Origin_weather string
Destination_weather string
Coordinates_ori string
Coordinates_dest string
Temp_c_ori string
Temp_f_ori string
Temp_c_dest string
Temp_f_dest string
}
//Here is the response data that I'm expected to get from my API calls.
//I'm trying to "push" Temp_c_dest and Temp_f_dest data into TravelItenaries.Temp_f_dest and TravelItenaries.Temp_c_dest
//While also changing the data types to fit above.
type Response struct {
Current struct {
LastUpdatedEpoch int `json:"last_updated_epoch"`
LastUpdated string `json:"last_updated"`
Temp_c_dest float64 `json:"temp_c"`
Temp_c_dest float64 `json:"temp_f"`
IsDay int `json:"is_day"`
} `json:"current"
}
weather.go
func (s *Server) getWeather(w http.ResponseWriter, r *http.Request) {
// open file
f, err := os.Open("challenge_dataset.csv")
if err != nil {
responses.ERROR(w, http.StatusBadRequest, fmt.Errorf("helpful error"))
return
}
// remember to close the file at the end of the program
defer f.Close()
// read csv values using csv.Reader
csvReader := csv.NewReader(f)
data, err := csvReader.ReadAll()
if err != nil {
responses.ERROR(w, http.StatusBadRequest, fmt.Errorf("helpful error"))
return
}
// convert records to array of structs
travelItenaries := createTravelItenaries(data)
// remove duplicate flight records
cleanTravelItenaries:= remDupKeys(travelItenaries)
// set up params for API get request
params := url.Values{
"key": []string{"xxx"},
"q": []string{""},
}
// Construct URL for API request
u := &url.URL{
Scheme: "https",
Host: "api.weatherapi.com",
Path: "/v1/current.json",
RawQuery: params.Encode(),
}
client := &http.Client{}
// Will need this to populate the params using a range over a struct
values := u.Query()
// loop through cleaned data set
for _, service := range cleanTravelItenaries {
// dynamically acquire data from struct to pass as parameter
values.Set("q", service.Coordinates_dest)
u.RawQuery = values.Encode()
req, err := http.NewRequest("GET", u.String(), nil)
if err != nil {
responses.ERROR(w, http.StatusBadRequest, fmt.Errorf("helpful error"))
return
}
resp, err := client.Do(req)
if err != nil {
responses.ERROR(w, http.StatusBadRequest, fmt.Errorf("helpful error"))
return
}
body, err := ioutil.ReadAll(resp.Body)
// create empty struct to parse response data with using Inmarshal
var responseData models.Response
json.Unmarshal(body, &responseData)
// Here is the issue, I don't think append might be the correct procedure here?
// I simply just need to pass this response data to my already existing struct
service.Temp_c_dest = append(responseData.Current.Temp_c_dest , cleanTravelItenaries )
service.Temp_f_dest = append(responseData.Current.Temp_f_dest , cleanTravelItenaries )
}
}
The errors I get are related to both append statements at the end of the range function.
first argument to append must be slice; have float64
first argument to append must be slice; have float64
for both append methods.
Also, note how type TravelItenaries struct uses string type for:
Temp_c_dest string
Temp_f_dest string
Hence why I also need to do some field type conversion from Float64 to string.
How can I extract the fields Temp_c_dest and Temp_f_dest from API response struct to TravelItenaries struct fields while changing datatypes?
EDIT:
I've managed to get this somewhat working, but only inside the for loop. The data is not being saved outside the function.
service.Temp_f_dest = strconv.FormatFloat(responseData.Current.Temp_f_dest, 'g', -1, 64)
service.Temp_c_dest = strconv.FormatFloat(responseData.Current.Temp_c_dest, 'g', -1, 64)
I am a little bit confused here and although I have searched a lot on this, something is clearly missing from my knowledge and I am asking your help.
I have created a Hyperledger Fabric Network and installed a chaincode in it. And I want to make a function that retrieves all the World State inputs about the Keys. I have done it already with the bytes.Buffer and it worked. But what I want to do is to do it with a struct.
So, I created the following struct that has only the key:
type WSKeys struct {
Key string `json: "key"`
Namespace string `json: "Namespace"`
}
And this is my code function:
func (s *SmartContract) getAllWsDataStruct(APIstub shim.ChaincodeStubInterface , args []string) sc.Response {
var keyArrayStr []WSKeys
resultsIterator, err := APIstub.GetQueryResult("{\"selector\":{\"_id\":{\"$ne\": null }} }")
if err != nil {
return shim.Error("Error occured when trying to fetch data: "+err.Error())
}
for resultsIterator.HasNext() {
// Get the next record
queryResponse, err := resultsIterator.Next()
if err != nil {
return shim.Error(err.Error())
}
fmt.Println(queryResponse)
var qry_key_json WSKeys
json.Unmarshal([]byte(queryResponse), &qry_key_json)
keyArray = append(keyArray, qry_key_json)
}
defer resultsIterator.Close()
all_bytes, _ := json.Marshal(keyArray)
fmt.Println(keyArray)
return shim.Success(all_bytes)
}
When executing the above I get the following error:
cannot convert queryResponse (type *queryresult.KV) to type []byte
I can get the results correctly if I, for example do this:
func (s *SmartContract) getAllWsDataStruct(APIstub shim.ChaincodeStubInterface , args []string) sc.Response {
var keyArray []string
resultsIterator, err := APIstub.GetQueryResult("{\"selector\":{\"_id\":{\"$ne\": null }} }")
if err != nil {
return shim.Error("Error occured when trying to fetch data: "+err.Error())
}
for resultsIterator.HasNext() {
// Get the next record
queryResponse, err := resultsIterator.Next()
if err != nil {
return shim.Error(err.Error())
}
fmt.Println(queryResponse)
keyArray = append(keyArray, queryResponse.Key)
}
defer resultsIterator.Close()
all_bytes, _ := json.Marshal(keyArray)
fmt.Println(keyArray)
return shim.Success(all_bytes)
}
But, why I get the above error when trying to add the queryResponse into a custom struct?
Do I need to add it to a struct that is only its type?
Please someone can explain what I am missing here?
The error statement is verbose enough to indicate, that your []byte conversion failed for the type queryResponse which, with a bit of lookup seems to be a struct type. In Go you cannot natively convert a struct instance to its constituent bytes without encoding using gob or other means.
Perhaps your intention was to use the Key record in the struct for un-marshalling
json.Unmarshal([]byte(queryResponse.Key), &qry_key_json)
I want to enable update functionality for my User object in my fiber/gorm backend. It works fine when I update all fields together using the Save function. However, when I do not have all fields present in the update request (for example only the Birthday field but not the Phone field) it overwrites the rest of the fields with their respective null values.
func UserUpdateByID(c *fiber.Ctx) error {
db := database.DBConn
// Parse the body to fit user entity
user := entities.User{}
if err := c.BodyParser(&user); err != nil {
return c.Status(500).SendString(err.Error())
}
// Update record
record := db.Save(&user)
if record.Error != nil {
return c.Status(500).SendString(record.Error.Error())
}
return c.JSON(record.Value)
When I change the line with record := db.Save(&user) to
mappedData, _ := StructToMap(user)
record := db.Model(&entities.User{}).Update(mappedData)
I receive the error that Update can not handle map of interfaces: sql: converting argument $10 type: unsupported type map[string]interface {}, a map
Update 1:
The mentioned StructToMap function looks like this:
func StructToMap(obj interface{}) (newMap map[string]interface{}, err error) {
data, err := json.Marshal(obj)
if err != nil {
return
}
err = json.Unmarshal(data, &newMap) // Convert to a map
return
}
Update 2:
The User object looks like:
type User struct {
gorm.Model
Identity string
Birthday time.Time
Phone string
City string
...
ActivityData []Activity
}
Looking, on gorm doc(https://gorm.io/docs/update.html), you can do something like this :
Use the Updates instead of Update.
db.Model(&user).Updates(User{Name: "hello", Age: 18, Active: false})
You can also use a db.Debug, to show the final query that gorm made, and see if matches with what are you expecting.
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 have parameter
id_user
phone_number
I want to decode to my struct
type User struct{
IDUser int `json:"id_user"`
PhoneNumber string `json:"phone_number"`
}
is it possible to decode into struct? I use gorilla schema. My Code:
func User(w http.ResponseWriter, r *http.Request){
var decoder = schema.NewDecoder()
var user User
if err := r.ParseForm(); err != nil {
fmt.Println(err)
}
err := decoder.Decode(&user, r.PostForm)
if err != nil {
fmt.Println(err)
}
respBody, err := json.Marshal(user)
w.Header().Set("Content-Type", "application/json")
w.WriteHeader(http.StatusOK)
w.Write(respBody)
}
i input id_user = 1 and phone_number = qwerty. But the result is id_user = 0 and phone_number = "".
If your mentioned two fields are query params you can directly read it like this way:
func User(w http.ResponseWriter, r *http.Request) {
idUser := r.URL.Query().Get("id_user")
phoneNumber := r.URL.Query().Get("phone_number")
var user User
id, err := strconv.Atoi(idUser)
if err != nil {
fmt.Println("error converting string to int")
return
}
user.IDUser = id
user.PhoneNumber = phoneNumber
respBody, _ := json.Marshal(user)
w.Header().Set("Content-Type", "application/json")
w.WriteHeader(http.StatusOK)
w.Write(respBody)
}
Otherwise you can directly pass the User struct in api payload and directly do the payLoad decoding like this
if err := json.NewDecoder(r.Body).Decode(&user); err != nil {
fmt.Println("error decoding api payload")
return
}
I think you should fix your tags from this:
type User struct{
IDUser int `json:id_user`
PhoneNumber string `json:phone_number`
}
to this:
type User struct{
IDUser int `json:"id_user"`
PhoneNumber string `json:"phone_number"`
}
So, you should use quotes in tag names.
If you want to decode them directly into a structure without getting the values of the fields one by one then you can use github.com/gorilla/schema. Refer to this question.
This answer may not be suitable for the question since the op was seeking help of using gorilla/schema package.
However, if someone were looking for a package to decode HTTP query params into a struct in Go, I will recommend an awesome package here:
ggicci/httpin
Disclaimer: I'm the creator and maintainer of this package.
httpin helps you easily decoding HTTP request data from
Query parameters, e.g. ?name=john&is_member=true
Headers, e.g. Authorization: xxx
Form data, e.g. username=john&password=******
JSON/XML Body, e.g. POST {"name":"john"}
Path variables, e.g. /users/{username}
File uploads
How to use?
type ListUsersInput struct {
Page int `in:"query=page"`
PerPage int `in:"query=per_page"`
IsMember bool `in:"query=is_member"`
}
func ListUsers(rw http.ResponseWriter, r *http.Request) {
input := r.Context().Value(httpin.Input).(*ListUsersInput)
if input.IsMember {
// Do sth.
}
// Do sth.
}
httpin is:
well documented: at https://ggicci.github.io/httpin/
well tested: coverage over 98%
open integrated: with net/http, go-chi/chi, gorilla/mux, gin-gonic/gin, etc.
extensible (advanced feature): by adding your custom directives. Read httpin - custom directives for more details.
awesome mentioned: https://github.com/avelino/awesome-go#forms