A component-based framework for Go
func root(ctx context.Context, props map[string]any) component.Component {
fmt.Println("root", props)
return component.NewGroup(
component.New(a, map[string]any{"name": "a"}),
component.New(b, map[string]any{"name": "b"}),
)
}
func a(ctx context.Context, props map[string]any) component.Component {
fmt.Println("a", props)
return component.NewGroup(
component.New(aa, map[string]any{"name": "aa"}),
component.New(ab, map[string]any{"name": "ab"}),
)
}
func b(ctx context.Context, props map[string]any) component.Component {
fmt.Println("b", props)
return component.New(ba, map[string]any{"name": "ba"})
}
func main() {
root := component.New(root, map[string]any{"name": "root"})
component.Run(context.Background(), root)
}func handle(ctx context.Context, props handler.Props) component.Component {
name := props.R.URL.Query().Get("name")
onGreet := func(msg string, err error) {
if err != nil {
props.W.WriteHeader(http.StatusBadRequest)
props.W.Write([]byte(err.Error()))
return
}
props.W.Write([]byte(msg))
}
return component.New(greetSvc, greetProps{name: name, greet: onGreet})
}
func main() {
http.ListenAndServe(":8080", handler.New(handle))
}See examples/parallel/main.go.
func sum(ctx context.Context, p props) component.Component {
if len(p.in) <= p.batchSize {
return apply(ctx, p)
}
return combine(ctx, p)
}
func split(ctx context.Context, p props) component.Component {
return component.NewGroup(
component.New(sum, props{in: p.in[:len(p.in)/2], out: p.out, batchSize: p.batchSize}),
component.New(sum, props{in: p.in[len(p.in)/2:], out: p.out, batchSize: p.batchSize}),
)
}
func apply(ctx context.Context, p props) component.Component {
var n int
for _, v := range p.in {
n += v
}
p.out <- n
return component.Component{}
}
func combine(ctx context.Context, p props) component.Component {
res := make(chan int)
go func() {
var n int
for i := 0; i < 2; i++ {
n += <-res
}
p.out <- n
}()
return component.New(split, props{in: p.in, out: res, batchSize: p.batchSize})
}func read(ctx context.Context, done chan struct{}) component.Component {
type state struct {
email string
valid bool
}
emailState, setEmailState := component.UseState(ctx, state{})
if !emailState.valid {
if len(emailState.email) > 0 {
fmt.Println("invalid input:", emailState.email)
}
onChangeEmail := func(s string) {
setEmailState(state{email: s, valid: strings.Contains(s, "@")})
}
return component.New(input, onChangeEmail)
}
done <- struct{}{}
return component.Component{}
}func reduce(i int, action string) int {
switch action {
case "add":
return i + 1
case "subtract":
return i - 1
default:
return i
}
}
func read(ctx context.Context, done chan struct{}) component.Component {
i, dispatch := component.UseReducer(ctx, reduce, 0)
fmt.Println(i)
onChange := func(s string) {
if s == "+" {
dispatch("add")
} else if s == "-" {
dispatch("subtract")
} else {
done <- struct{}{}
}
}
return component.New(input, onChange)
}