I'm trying to unmarshal some json data I get from a web service. I have simplified the problem which is shown in the code below. My question is can I make version (c) in the code work..
I know it works for single number values as shown for "timestamp" by adding the option ",string" to the json annotation. But I can't figure out how or if this works for arrays of string encoded numbers too. (See "conversions" in the example json listed in the code)
package main
import (
"encoding/json"
"fmt"
)
//version (a)
type JsonData1 struct {
TimeStamp uint64 `json:"timestamp,string"`
Conversions [][2]string `json:"conversions"`
}
//version (b)
type JsonData2 struct {
TimeStamp uint64 `json:"timestamp,string"`
Conversions [][2]json.Number `json:"conversions"`
}
//version (c)
type JsonData3 struct {
TimeStamp uint64 `json:"timestamp,string"`
Conversions [][2]float32 `json:"conversions"`
}
const incomingJson string = `{"timestamp": "1407178369", "conversions": [["1.021", "2.124"], ["2.432", "3.923"], ["3.234", "5.001"]]}`
func main() {
var data1 JsonData1
if err1 := json.Unmarshal([]byte(incomingJson), &data1); err1 != nil {
fmt.Println("Error unmarshaling with struct JsonData1")
fmt.Println("--> ", err1.Error())
} else {
fmt.Println("Success unmarshaling with struct JsonData1")
fmt.Println("--> ", data1)
}
var data2 JsonData2
if err2 := json.Unmarshal([]byte(incomingJson), &data2); err2 != nil {
fmt.Println("Error unmarshaling with struct JsonData2")
fmt.Println("--> ", err2.Error())
} else {
fmt.Println("Success unmarshaling with struct JsonData2")
fmt.Println("--> ", data2)
}
var data3 JsonData3
if err3 := json.Unmarshal([]byte(incomingJson), &data3); err3 != nil {
fmt.Println("Error unmarshaling with struct JsonData3")
fmt.Println("--> ", err3.Error())
} else {
fmt.Println("Success unmarshaling with struct JsonData3")
fmt.Println("--> ", data3)
}
}
If i compile and run the code I get this output:
Success unmarshaling with struct JsonData1
--> {1407178369 [[1.021 2.124] [2.432 3.923] [3.234 5.001]]}
Success unmarshaling with struct JsonData2
--> {1407178369 [[1.021 2.124] [2.432 3.923] [3.234 5.001]]}
Error unmarshaling with struct JsonData3
--> json: cannot unmarshal string into Go value of type float32
You can run the code here: http://play.golang.org/p/4TC0IgCI8H
Is there a way to achieve unmarshaling into struct version (c)? Thanks for your help!