Method decode

mapstructure.go:421–505

Decodes an unknown data type into a specific reflection value.

(name string, input interface{}, outVal reflect.Value)

// Decodes an unknown data type into a specific reflection value.
func (d *Decoder) decode(name string, input interface{}, outVal reflect.Value) error {
	var inputVal reflect.Value
	if input != nil {
		inputVal = reflect.ValueOf(input)

		// We need to check here if input is a typed nil. Typed nils won't
		// match the "input == nil" below so we check that here.
		if inputVal.Kind() == reflect.Ptr && inputVal.IsNil() {
			input = nil
		}
	}

	if input == nil {
		// If the data is nil, then we don't set anything, unless ZeroFields is set
		// to true.
		if d.config.ZeroFields {
			outVal.Set(reflect.Zero(outVal.Type()))

			if d.config.Metadata != nil && name != "" {
				d.config.Metadata.Keys = append(d.config.Metadata.Keys, name)
			}
		}
		return nil
	}

	if !inputVal.IsValid() {
		// If the input value is invalid, then we just set the value
		// to be the zero value.
		outVal.Set(reflect.Zero(outVal.Type()))
		if d.config.Metadata != nil && name != "" {
			d.config.Metadata.Keys = append(d.config.Metadata.Keys, name)
		}
		return nil
	}

	if d.config.DecodeHook != nil {
		// We have a DecodeHook, so let's pre-process the input.
		var err error
		input, err = DecodeHookExec(d.config.DecodeHook, inputVal, outVal)
		if err != nil {
			return fmt.Errorf("error decoding '%s': %s", name, err)
		}
	}

	var err error
	outputKind := getKind(outVal)
	addMetaKey := true
	switch outputKind {
	case reflect.Bool:
		err = d.decodeBool(name, input, outVal)
	case reflect.Interface:
		err = d.decodeBasic(name, input, outVal)
	case reflect.String:
		err = d.decodeString(name, input, outVal)
	case reflect.Int:
		err = d.decodeInt(name, input, outVal)
	case reflect.Uint:
		err = d.decodeUint(name, input, outVal)