go～大型项目的参数注册

目标对象

如何合理的注册 Config.Process 中的 Middleware ?

// 目标对象
type Config struct {
	Process struct {
		Middleware []CommonMiddleware
	}
}

type CommonMiddleware interface {
	PreProcess(ctx *context.Context, event *ProcessEvent) error
	PostProcess(ctx *context.Context, err *error, event *ProcessEvent) error
}

SDK实现

提供 Init 函数

// 定义一个函数类型，后续要用该类型填充 Config
type CfgOption func(*Config)

func Init(name string, ops ...CfgOption) {
	c := &Config{}
	c.name = name
	c.Producer.Middleware = []CommonMiddleware{}
	for _, op := range ops {
		op(c)
	}
	return c, nil
}

业务代码

定制注册

// 业务实现
type myMW struct{}

func (m *myMW) PreProcess(*context.Context, *ProcessEvent) error          { return nil }
func (m *myMW) PostProcess(*context.Context, *error, *ProcessEvent) error { return nil }


// 注册
var processMWCfg = WithProcessMiddleware(&myMW{})

func WithProcessMiddleware(m CommonMiddleware) CfgOption {
	return func(config *Config) {
		config.Producer.Middleware = append(config.Producer.Middleware, m)
	}
}

func WithProcessMW() CfgOption {
	return processMWCfg
}

Init("123", WithProcessMW())

默认注册

type noOP struct{}

func (m *noOP) PreProcess(*context.Context, *ProcessEvent) error          { return nil }
func (m *noOP) PostProcess(*context.Context, *error, *ProcessEvent) error { return nil }

type myMW struct{
	noOP
	addr string
	email string
}