freddy

freddy

Freddy extends on Go's encoding/json by adding support for multiple tags. I hope to get this merged into the standard library eventually.

New functions:

• MarshalTag(interface{}, ...string)- marshals a type using the specified tag(s) instead of json
• UnmarshalTag([]byte, interface{}, ...string)- unmarshals into a type using the specified tag(s) instead of json

Tags are tried in user-defined order. The first tag that exists is used. For example:

type Struct struct {
    A string `json:"B" api:"-" db:"a"`
    B string `json:"-" db:"b"`
}
func main() {
    a := A{"hi","bye"}
    json.Marshal(a) // {"B":"hi"}
    json.MarshalTag(a) // {"A":"hi","B":"bye"}
    json.MarshalTag(a, "api") // {"B":"bye"}
    json.MarshalTag(a, "db") // {"a":"hi","b":"bye"}
    json.MarshalTag(a, "api", "json") // {"B":"hi"}
}

When using the (Un|M)arshalTag functions, the "json" tag is not automatically appended. (Un|M)arshal are just aliases that pass in "json".