poly.go

package main

import "fmt"
import "encoding/json"
import "time"

type (
	Container map[string]Variable
	Variable interface {
		GetName() string
		SetName(string)
		GetType() int
		SetType(int)
	}
	VariableImpl struct {
		Name string
		Type int
	}
	StringVariable struct {
		VariableImpl
		Value string
	}
	StringListVariable struct {
		VariableImpl
		Value []string
	}
	CountDownVariable struct {
		VariableImpl
		Value time.Time
	}
)

func (cont *Container) UnmarshalJSON(data []byte) error {
	mpv := map[string]VariableImpl{}
	_ = json.Unmarshal(data, &mpv)
	mpvr := map[string]json.RawMessage{}
	_ = json.Unmarshal(data, &mpvr)
	for index, vimp := range mpv {
		switch vimp.Type {
		case 0:
			strvar := StringVariable{}
			_ = json.Unmarshal(mpvr[index], &strvar)
			(*cont)[index] = strvar
		case 1:
			strlvar := StringListVariable{}
			_ = json.Unmarshal(mpvr[index], &strlvar)
			(*cont)[index] = strlvar
		case 2:
			cdvar := CountDownVariable{}
			_ = json.Unmarshal(mpvr[index], &cdvar)
			(*cont)[index] = cdvar
		}
	}
        return nil
}

func (variable VariableImpl) GetType() int {
	return variable.Type
}
func (variable VariableImpl) SetType(new_type int) {
	variable.Type = new_type
}

func (variable VariableImpl) GetName() string {
	return variable.Name
}
func (variable VariableImpl) SetName(new_name string) {
	variable.Name = new_name
}

func NewStringVariable(name string, value string) (intvar StringVariable) {
	intvar = StringVariable{VariableImpl: VariableImpl{Name: name, Type: 0}, Value: value}
	return
}

func NewStringListVariable(name string, value []string) (intvar StringListVariable) {
	intvar = StringListVariable{VariableImpl: VariableImpl{Name: name, Type: 1}, Value: value}
	return
}

func NewCountDownVariable(name string, value time.Time) (countdown CountDownVariable) {
	countdown = CountDownVariable{VariableImpl: VariableImpl{Name: name, Type: 2}, Value: value}
	return
}

func main() {
	/*container := Container{
				"location": NewStringVariable("location", "Bangalore"), 
				"countdown1": NewCountDownVariable("countdown1", time.Now()), 
				"languages": NewStringListVariable("languages", []string{"Tamil", "Telugu", "English", "Hindi"}),
				}
	bytes, _ :=json.Marshal(container)
	str := string(bytes)
	fmt.Println(str)*/

	data := `{"countdown1":{"Name":"countdown1","Type":2,"Value":"2009-11-10T23:00:00Z"},"languages":{"Name":"languages","Type":1,"Value":["Tamil","Telugu","English","Hindi"]},"location":{"Name":"location","Type":0,"Value":"Bangalore"}}
`
	container := Container{}
	json.Unmarshal([]byte(data), &container)
	fmt.Println(container)
}

poly1.go

package main

import "fmt"
import "encoding/json"
import "time"
import "bytes"
import "errors"

type (
	Container struct {
		Variables map[string]Variable
	}
	Variable interface {
		GetName() string
		SetName(string)
		GetType() int
		SetType(int)
	}
	VariableImpl struct {
		Name string
		Type int
	}
	StringVariable struct {
		VariableImpl
		Value string
	}
	StringListVariable struct {
		VariableImpl
		Value []string
	}
	CountDownVariable struct {
		VariableImpl
		Value time.Time
	}
)

func (cont *Container) UnmarshalJSON(data []byte) error {
        b := bytes.NewBuffer(data)
        dec := json.NewDecoder(b)
        mp := map[string]json.RawMessage{}
        if err := dec.Decode(&mp); err != nil {
                return err
        }
	vars, ok := mp["Variables"]
	if ok {
		mpv := map[string]VariableImpl{}
		_ = json.Unmarshal(vars, &mpv)
		mpvr := map[string]json.RawMessage{}
		_ = json.Unmarshal(vars, &mpvr)
		cont.Variables = map[string]Variable{}
		for index, vimp := range mpv {
			switch vimp.Type {
			case 0:
				strvar := StringVariable{}
				_ = json.Unmarshal(mpvr[index], &strvar)
				cont.Variables[index] = strvar
			case 1:
				strlvar := StringListVariable{}
				_ = json.Unmarshal(mpvr[index], &strlvar)
				cont.Variables[index] = strlvar
			case 2:
				cdvar := CountDownVariable{}
				_ = json.Unmarshal(mpvr[index], &cdvar)
				cont.Variables[index] = cdvar
			}
		}
	} else {
		return errors.New("error")
	}
        return nil
}

func (variable VariableImpl) GetType() int {
	return variable.Type
}
func (variable VariableImpl) SetType(new_type int) {
	variable.Type = new_type
}

func (variable VariableImpl) GetName() string {
	return variable.Name
}
func (variable VariableImpl) SetName(new_name string) {
	variable.Name = new_name
}

func NewStringVariable(name string, value string) (intvar StringVariable) {
	intvar = StringVariable{VariableImpl: VariableImpl{Name: name, Type: 0}, Value: value}
	return
}

func NewStringListVariable(name string, value []string) (intvar StringListVariable) {
	intvar = StringListVariable{VariableImpl: VariableImpl{Name: name, Type: 1}, Value: value}
	return
}

func NewCountDownVariable(name string, value time.Time) (countdown CountDownVariable) {
	countdown = CountDownVariable{VariableImpl: VariableImpl{Name: name, Type: 2}, Value: value}
	return
}

func main() {
	/*container := Container{Variables: map[string]Variable{
				"location": NewStringVariable("location", "Bangalore"), 
				"countdown1": NewCountDownVariable("countdown1", time.Now()), 
				"languages": NewStringListVariable("languages", []string{"Tamil", "Telugu", "English", "Hindi"}),
				},
			}
	bytes, _ :=json.Marshal(container)
	str := string(bytes)
	fmt.Println(str)*/

	data := `{"Variables":{"countdown1":{"Name":"countdown1","Type":2,"Value":"2009-11-10T23:00:00Z"},"languages":{"Name":"languages","Type":1,"Value":["Tamil","Telugu","English","Hindi"]},"location":{"Name":"location","Type":0,"Value":"Bangalore"}}}`
	container := Container{}
	json.Unmarshal([]byte(data), &container)
	fmt.Println(container)
}