Hi please I need some help, I'm coming in from nodejs and looking for a way to unmarshall a nested json so that it becomes simple json pairs. This is a sample of my nested json.
{
"id": 1000004,
"reference": "T0000",
"amount": 700000,
"paid_at": "2022-07-24T00:49:13.000Z",
"created_at": "2022-07-24T00:49:08.000Z",
"Metadata": {
"Custom_fields": [
{
"display_name": "MeterNumber",
"value": "123456789"
},
{
"display_name": "AccountNumber",
"value": "123456"
}
]
}
}
I want to achieve this:
{
"id": 1000004,
"reference": "T0000",
"amount": 700000,
"paid_at": "2022-07-24T00:49:13.000Z",
"created_at": "2022-07-24T00:49:08.000Z",
"meter_number": "123456789",
"account_number": "123456",
}
it used to be a deep root nested payload, I have used the struct type to isolate the relevant pairs and array but it's still not in the format I need it to be for passing to DB. Pointers and corrections will be appreciated.
How can I unmarshall nested json to become simple json pairs Golang?
This is the original data
Data = []byte(`{
"status": true,
"message": "Transactions retrieved",
"data": [
{
"id": 10000000,
"domain": "test",
"status": "success",
"reference": "T0000000000",
"amount": 700000,
"message": null,
"gateway_response": "Successful",
"paid_at": "2022-07-24T00:49:13.000Z",
"created_at": "2022-07-24T00:49:08.000Z",
"channel": "card",
"currency": "NGN",
"ip_address": "102.89.32.12",
"metadata": {
"custom_fields": [
{
"display_name": "MeterNumber",
"variable_name": "meternumber",
"value": "123456789"
},
{
"display_name": "AccountNumber",
"variable_name": "accountnumber",
"value": "123456"
}
],
"referrer": "https://example.com/"
},
"log": {
"start_time": 1658623749,
"time_spent": 4,
"attempts": 1,
"errors": 0,
"success": true,
"mobile": false,
"input": [],
"history": [
{
"type": "action",
"message": "Attempted to pay with card",
"time": 2
},
{
"type": "success",
"message": "Successfully paid with card",
"time": 4
}
]
},
"fees": 20500,
"fees_split": null,
"customer": {
"id": 87000000,
"first_name": "foo",
"last_name": "foo",
"email": "[email protected]",
"phone": "08090000000",
"metadata": null,
"customer_code": "CUS_foo",
"risk_action": "default"
},
"authorization": {
"authorization_code": "AUTH_foo",
"bin": "40123456789",
"last4": "40000",
"exp_month": "12",
"exp_year": "2030",
"channel": "card",
"card_type": "visa ",
"bank": "TEST BANK",
"country_code": "NG",
"brand": "visa",
"reusable": true,
"signature": "SIG_foo",
"account_name": null
},
"plan": {},
"split": {},
"subaccount": {},
"order_id": 800000,
"paidAt": "2022-07-24T00:49:13.000Z",
"createdAt": "2022-07-24T00:49:08.000Z",
"requested_amount": 700000,
"source": {
"source": "checkout",
"type": "web",
"identifier": null,
"entry_point": "request_inline"
},
"pos_transaction_data": null
},
{
"id": 1000000,
"domain": "test",
"status": "success",
"reference": "T13456789",
"amount": 500000,
"message": null,
"gateway_response": "Successful",
"paid_at": "2022-07-24T00:28:34.000Z",
"created_at": "2022-07-24T00:28:08.000Z",
"channel": "card",
"currency": "NGN",
"ip_address": "192.168.1.1",
"metadata": {
"custom_fields": [
{
"display_name": "MeterNumber",
"variable_name": "meternumber",
"value": "123456789"
},
{
"display_name": "AccountNumber",
"variable_name": "accountnumber",
"value": "123456"
}
],
"referrer": "https://example.com"
},
"log": {
"start_time": 1658622488,
"time_spent": 26,
"attempts": 1,
"errors": 0,
"success": true,
"mobile": false,
"input": [],
"history": [
{
"type": "action",
"message": "Set payment method to: bank",
"time": 15
},
{
"type": "action",
"message": "Set payment method to: ussd",
"time": 16
},
{
"type": "action",
"message": "Set payment method to: bank",
"time": 19
},
{
"type": "action",
"message": "Set payment method to: card",
"time": 22
},
{
"type": "action",
"message": "Attempted to pay with card",
"time": 25
},
{
"type": "success",
"message": "Successfully paid with card",
"time": 26
}
]
},
"fees": 17500,
"fees_split": null,
"customer": {
"id": 870000000,
"first_name": "foo",
"last_name": "foo",
"email": "[email protected]",
"phone": "0809000000",
"metadata": null,
"customer_code": "CUS_xxxx",
"risk_action": "default"
},
"authorization": {
"authorization_code": "AUTH_xxxx",
"bin": "400000",
"last4": "40000",
"exp_month": "12",
"exp_year": "2030",
"channel": "card",
"card_type": "visa ",
"bank": "TEST BANK",
"country_code": "NG",
"brand": "visa",
"reusable": true,
"signature": "xxxxxx",
"account_name": null
},
"plan": {},
"split": {},
"subaccount": {},
"order_id": 827512,
"paidAt": "2022-07-24T00:28:34.000Z",
"createdAt": "2022-07-24T00:28:08.000Z",
"requested_amount": 500000,
"source": {
"source": "checkout",
"type": "web",
"identifier": null,
"entry_point": "request_inline"
},
"pos_transaction_data": null
}
],
"meta": {
"total": 2,
"total_volume": 12000,
"skipped": 0,
"perPage": 50,
"page": 1,
"pageCount": 1
}
}`)
here's what i did:
type Uservariabledata struct {
//json.RawMessage `json:"custom_field"`
Display_name string `json:"display_name"`
Value string `json:"value"`
}
// struct
type UserDataDetail struct {
Custom_fields []Uservariabledata
}
// struct
type UserData struct {
Id int `json:"id"`
Reference string `json:"reference"`
Amount uint `json:"amount"`
Paid_at string `json:"paid_at"`
Created_at string `json:"created_at"`
Metadata UserDataDetail
}
// Payload struct
type Payload struct {
Status bool `json:"status"`
Message string `json:"message"`
Data []UserData
Meta json.RawMessage `json:"meta"`
}
func (p *Payload) UnmarshalJSON(data []byte) error {
type payload struct {
Status bool `json:"status"`
Message string `json:"message"`
Data []UserData
Meta json.RawMessage `json:"meta"`
}
payld := &payload{}
err := json.Unmarshal(data, payld)
if err != nil {
return err
}
p.Status = payld.Status
p.Message = payld.Message
p.Data=payld.Data
p.Meta=payld.Meta
return nil
}
// GetUserAmountPaid endpoint, this was done in my controller.go
func GetUserAmountPaid(c echo.Context) (err error) {
respData := Data
payld := Payload{}
err = json.Unmarshal(respData, &payld)
if err != nil {
panic(err)
}
return c.JSON(http.StatusOK, payld.Data)
}
CodePudding user response：
You've mostly identified that you want to have separate structs for the "real data" and the "transferred data".
type RealData struct {
Id int `json:"id"`
...
MeterNumber string `json:"meter_number"`
AccountNumber string `json:"account_number"`
}
The trick is that your "transfer data" isn't quite right, it needs to match the format of the JSON being parsed.
type TransferData struct {
Id int
// ...
Metadata struct {
Custom_fields []struct{
Display_name string
Variable_name string
Value string
}
}
}
Then it's just a matter of unmarshaling into an object of the "transfer data" type and copying it into your "real data".
func (realData *RealData) UnmarshalJSON(data []byte) error {
var transferData TransferData
err := json.Unmarshal(data, &transferData)
if err != nil {
return err
}
realData.Id = transferData.Id
// ...
// Now we must cherry-pick the known custom metadata fields we
// care about into the desired fields of our real data.
for _, cf := range transferData.Metadata.Custom_fields {
switch cf.Display_name {
case "MeterNumber":
realData.MeterNumber = cf.Value
case "AccountNumber":
realData.AccountNumber = cf.Value
}
}
return nil
}
CodePudding user response：
Got it fixed!
type RealData struct {
Id int `json:"id"`
Reference string `json:"reference"`
Amount uint `json:"amount"`
Paid_at string `json:"paid_at"`
Created_at string `json:"created_at"`
MeterNumber string `json:"meter_number"`
AccountNumber string `json:"account_number"`
}
Then for matching the JSON for my real data
type TransferData struct {
Status bool
Message string
Data []struct{
Id int
Reference string
Amount uint
Paid_at string
Created_at string
Metadata struct {
Custom_fields []struct{
Display_name string
Variable_name string
Value string
}
}
}
Meta json.RawMessage
}
and finally marshaling it:
func (realData *RealData) UnmarshalJSON(data []byte) error {
var transferData TransferData
err := json.Unmarshal(data, &transferData)
if err != nil {
return err
}
for _, td := range transferData.Data {
realData.Id = td.Id
realData.Reference = td.Reference
realData.Amount = td.Amount
realData.Paid_at = td.Paid_at
realData.Created_at = td.Created_at
for _, rd := range td.Metadata.Custom_fields {
switch rd.Display_name {
case "MeterNumber":
realData.MeterNumber = rd.Value
case "AccountNumber":
realData.AccountNumber = rd.Value
}
}
}
return nil
}
Thanks to maeric for providing the initial solution which I upgraded.
I hope this helps someone.