README.md
# wire
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Wire is runtime depedency injection/wiring for golang. It's designed to be strict to avoid your go application running without proper dependency injected.
Features:
- Strictly validates dependency and prevents missing or ambiguous dependency.
- Check againts possible forgotten `wire` tag.
- Easily connect and resolve object anywhere.
- Annotates ambiguous interface type using connection name or implementation name.
## Install
```bash
go get github.com/Fs02/wire
```
## Example
```golang
package wire_test
import (
"fmt"
"github.com/Fs02/wire"
)
type Listener struct{}
func (listener Listener) Next() string {
return "system"
}
type Printer interface {
Exec(string) error
}
type SystemPrint struct {
App string `wire:""`
}
func (systemPrint SystemPrint) Exec(msg string) error {
fmt.Println("[" + systemPrint.App + "] System: " + msg)
return nil
}
type UserPrint struct {
App string `wire:""`
Target string
}
func (userPrint UserPrint) Exec(msg string) error {
fmt.Println("[" + userPrint.App + "]" + userPrint.Target + ": " + msg)
return nil
}
type Service struct {
// Each of `wire`` tag below indicate fields to be wired with apporpriate component.
// value inside `wire` tag indicate the name of the component and optionally it's type.
// `wire` with empty value will be wired with default value (named using empty string).
// Ambiguous field can be resolved by adding it's type, name or both (separated using comma) to the `wire` tag.
// Don't worry if you forgot to add wire tag to an interface or a pointer, wire will warn you if any nil field are found.
// To ignore wiring on specific field, you can use add `wire:"-"`.
Listener Listener `wire:""`
SystemPrint Printer `wire:",SystemPrint"`
FooUserPrint Printer `wire:"foo"`
BooUserPrint Printer `wire:"boo,UserPrint"`
}
func (service Service) Update() error {
switch service.Listener.Next() {
case "system":
return service.SystemPrint.Exec("hello from system")
case "user-foo":
return service.FooUserPrint.Exec("hello from foo")
case "user-boo":
return service.BooUserPrint.Exec("hello from boo")
default:
return nil
}
}
func init() {
// add components to be wired by the library.
// wire all components only once and as early as possible.
wire.Connect("CoolApp")
wire.Connect(Listener{}) // we don't need to pass by reference here, since it doesn't require any wiring.
wire.Connect(&SystemPrint{}) // we need to pass by reference it to allow wiring, wire will panic if we pass by value.
wire.Connect(&UserPrint{Target: "foo"}, "foo") // wire a UserPrint named by "foo".
wire.Connect(&UserPrint{Target: "boo"}, "boo") // wire a UserPrint named by "boo", wire will panic if there's duplicate components detected.
wire.Connect(&Service{})
// Apply wiring
wire.Apply()
}
func Example() {
// Resolve a service component to be used later.
var service Service
wire.Resolve(&service)
service.Update()
// Output: [CoolApp] System: hello from system
}
```
## License
Released under the [MIT License](https://github.com/Fs02/wire/blob/master/LICENSE)
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