How to make a 2-level depth type definition in a struct? - go

Question

Currently I have the following definition for my structs:
type WholeJson struct {
Features []Temp
}
type Temp struct {
Properties Human
}
type Human struct {
Name string
Age uint
}
Which is working when unmarshaling a JSON string into a variable of type WholeJson, which would have the following structure:
{
"features":[
{
"properties": {
"name": "John Doe",
"age": 50
}
}
]
}
Go Playground sample here: https://play.golang.org/p/3WTLxR0EZWP
But I don't know how to write it in a simpler way. It is obvious that not both WholeJson and Temp are necessary as far as using the information they will hold. The only reason I have Temp is because I simply don't know how to avoid defining it (and still have the program work).
Presumably the Features property of WholeJson would have an array to some interface{}, but I can't nail the syntax. And I'm assuming the code for reading the unmarshalled data (from the playground sample) will stay the same.
How would I "squash" those those two structs into one (the Human struct i'm assuming is okay if it stays on its own), and still have useful data in the end, where I could loop through the features key to go through all the data?

Answer 1

It's OK to define a type for each level of the hierarchy and preferred when constructing values from Go code. The types do not need to be exported.
Use anonymous types to eliminate the defined types:
var sourceData struct {
Features []struct {
Properties Human
}
}
var jsonString string = `{
"features":[
{
"properties": {
"name": "John Doe",
"age": 50
}
}
]
}`
json.Unmarshal([]byte(jsonString), &sourceData)
fmt.Println(sourceData.Features[0].Properties.Name)