README
¶
Extensions for mapstructure
Installation
go get github.com/sagikazarmark/mapstructurex
Development
For an optimal developer experience, it is recommended to install Nix and direnv.
Run the test suite:
just test
License
The project is licensed under the MIT License.
Documentation
¶
Overview ¶
Package mapstructurex contains various extensions (primarily decoding hooks) to mapstructure.
Index ¶
Examples ¶
Constants ¶
This section is empty.
Variables ¶
This section is empty.
Functions ¶
func MapDecoderHookFunc ¶
func MapDecoderHookFunc() mapstructure.DecodeHookFunc
MapDecoderHookFunc returns a mapstructure.DecodeHookFunc that applies maps to the DecodeMap function, when the target type implements the MapDecoder interface.
Example ¶
package main
import (
"fmt"
"github.com/mitchellh/mapstructure"
"github.com/sagikazarmark/mapstructurex"
)
type Person struct {
Name string
Age int
}
func (p *Person) DecodeMap(v map[string]any) error {
type alias Person
var result alias
decoder, err := CreateDecoderWithMapDecoderHook(&result)
if err != nil {
return err
}
err = decoder.Decode(v)
if err != nil {
return err
}
*p = Person(result)
return nil
}
func (p Person) String() string {
return fmt.Sprintf("%s: %d", p.Name, p.Age)
}
func CreateDecoderWithMapDecoderHook(result any) (*mapstructure.Decoder, error) {
return mapstructure.NewDecoder(&mapstructure.DecoderConfig{
DecodeHook: mapstructurex.MapDecoderHookFunc(),
Metadata: nil,
Result: result,
})
}
func main() {
var person Person
decoder, _ := CreateDecoderWithMapDecoderHook(&person)
input := map[string]any{
"name": "Bob",
"age": 42,
}
_ = decoder.Decode(input)
fmt.Println(person)
}
Output: Bob: 42
Example (Polymorphic) ¶
package main
import (
"errors"
"fmt"
"github.com/mitchellh/mapstructure"
"github.com/sagikazarmark/mapstructurex"
)
func CreateDecoderWithMapDecoderHook(result any) (*mapstructure.Decoder, error) {
return mapstructure.NewDecoder(&mapstructure.DecoderConfig{
DecodeHook: mapstructurex.MapDecoderHookFunc(),
Metadata: nil,
Result: result,
})
}
// Config is a struct that implements a custom decoding function.
// The embedded [Fooer] interface provides polymorphism.
// Alternative implementations of [Fooer] can provide different configurations.
type Config struct {
Fooer
}
// Fooer is an interface that provides polymorphism for [Config].
type Fooer interface {
Foo() string
}
// RawConfig mimics the structure of configuration (for example in a config file).
// Type determines the [Fooer] implementation, Config is the input for the implementation.
type RawConfig struct {
Type string
Config map[string]any
}
func (c *Config) DecodeMap(v map[string]any) error {
var rawConfig RawConfig
err := mapstructure.Decode(v, &rawConfig)
if err != nil {
return err
}
switch rawConfig.Type {
case "bar":
var bar ConfigBar
err := mapstructure.Decode(rawConfig.Config, &bar)
if err != nil {
return err
}
c.Fooer = bar
case "baz":
var baz ConfigBaz
err := mapstructure.Decode(rawConfig.Config, &baz)
if err != nil {
return err
}
c.Fooer = baz
default:
return errors.New("unknown type")
}
return nil
}
// ConfigBar is a [Fooer].
type ConfigBar struct {
Bar string
}
func (c ConfigBar) Foo() string {
return c.Bar
}
// ConfigBaz is a [Fooer].
type ConfigBaz struct {
Baz string
}
func (c ConfigBaz) Foo() string {
return c.Baz
}
func main() {
var config Config
decoder, _ := CreateDecoderWithMapDecoderHook(&config)
input := map[string]any{
"type": "baz",
"config": map[string]any{
"baz": "bat",
},
}
err := decoder.Decode(input)
if err != nil {
panic(err)
}
fmt.Println(config.Foo())
}
Output: bat
func StringToNetIPAddrHookFunc ¶
func StringToNetIPAddrHookFunc() mapstructure.DecodeHookFunc
StringToNetIPAddrHookFunc returns a mapstructure.DecodeHookFunc that converts strings to netip.Addr.
Will be removed once https://github.com/mitchellh/mapstructure/pull/315 is merged.
func StringToNetIPAddrPortHookFunc ¶
func StringToNetIPAddrPortHookFunc() mapstructure.DecodeHookFunc
StringToNetIPAddrPortHookFunc returns a mapstructure.DecodeHookFunc that converts strings to netip.AddrPort.
Will be removed once https://github.com/mitchellh/mapstructure/pull/315 is merged.
Types ¶
type MapDecoder ¶
MapDecoder is the interface implemented by an object that can decode a raw map representation of itself.
Source Files