Sharing Domain Logic for Embedded Structs

Rob_Wilkerson_1665 0
Viewed 41

I have a number of structs that share some common properties and logic, but I haven't been able to find a way to share logic that works. Basically, I have a file as part of a package that handles "widgets". I wanted to have a general Widget struct that's embedded in each specified widget struct WidgetA and WidgetB, then share a bit of logic during the creation process. For example:

type Widget struct {
    name string
}
type WidgetA struct {
    Widget
    inspector string
}
type WidgetB struct {
    Widget
    length int
    height int
}

func (w *Widget) Init() {
    // Do some shared things
    // Then figure out which _type_ of Widget this is and delegate
    // to the appropriate receiver function
}
func (wa *WidgetA) Create () { ... }
func (wb *WidgetB) Create () { ... }

On the calling end, maybe something like this:

widgetA := &WidgetA{}
widgetA.Init()

I can't find a working solution to share the logic in Go, so I'd like to either understand where I'm going wrong or, if I'm going wrong be trying to apply old habits where they don't belong, figure out the most idiomatic way of accomplishing the same goal using Go.

Insight appreciated!

go
1 Answers

You can do something like this:

func (w *Widget) Init() {...}

func (wa *WidgetA) Init() {
   wa.Widget.Init()
   // init widgetA
}

func (wb *WidgetB) Init() {
   wb.Widget.Init()
   // init widgetB
}


widgetA:=WidgetA{}
widgetA.Init()

If you don't know the type of the object you're initializing, you can use an interface:

type Initer interface {
   Init()
}

func f(w Initer) {
  w.Init() // Call the Init() for the underlying widget type
}
user_119239990
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