44 lines
1013 B
Go
44 lines
1013 B
Go
|
package service
|
||
|
|
|
||
|
|
import (
|
||
|
|
"errors"
|
||
|
|
)
|
||
|
|
|
||
|
|
var (
|
||
|
|
// ErrNotImplemented is the error when a service is accessed
|
||
|
|
// and no implementation was provided
|
||
|
|
ErrNotImplemented = errors.New("service not implemented")
|
||
|
|
)
|
||
|
|
|
||
|
|
// Provider is a provider for a service
|
||
|
|
type Provider func(ctn *Container) (interface{}, error)
|
||
|
|
|
||
|
|
// Container is a simple service container for dependency injection
|
||
|
|
type Container struct {
|
||
|
|
providers map[Name]Provider
|
||
|
|
}
|
||
|
|
|
||
|
|
// Name is a name of a service
|
||
|
|
type Name string
|
||
|
|
|
||
|
|
// Provide registers a provider for the survey.Service
|
||
|
|
func (c *Container) Provide(name Name, provider Provider) {
|
||
|
|
c.providers[name] = provider
|
||
|
|
}
|
||
|
|
|
||
|
|
// Service retrieves a service implementation based on its name
|
||
|
|
func (c *Container) Service(name Name) (interface{}, error) {
|
||
|
|
provider, exists := c.providers[name]
|
||
|
|
if !exists {
|
||
|
|
return nil, ErrNotImplemented
|
||
|
|
}
|
||
|
|
return provider(c)
|
||
|
|
}
|
||
|
|
|
||
|
|
// NewContainer returns a new empty service container
|
||
|
|
func NewContainer() *Container {
|
||
|
|
return &Container{
|
||
|
|
providers: make(map[Name]Provider),
|
||
|
|
}
|
||
|
|
}
|