feat: improve component support

context.go

@@ -16,16 +16,16 @@ import (
 //
 // It binds user state and actions, manages reactive signals, and defines UI through View.
 type Context struct {
-	id             string
+	id                string
-	app            *via
+	app               *via
-	view           func() h.H
+	view              func() h.H
-	components     map[string]*Context
+	componentRegistry map[string]*Context
-	componentsMux  sync.RWMutex
+	parentPageCtx     *Context
-	sse            *datastar.ServerSentEventGenerator
+	sse               *datastar.ServerSentEventGenerator
-	actionRegistry map[string]func()
+	actionRegistry    map[string]func()
-	signals        map[string]*signal
+	signals           map[string]*signal
-	signalsMux     sync.Mutex
+	signalsMux        sync.Mutex
-	createdAt      time.Time
+	createdAt         time.Time
 }
 
 // View defines the UI rendered by this context.
@@ -40,25 +40,64 @@ func (c *Context) View(f func() h.H) {
 	c.view = func() h.H { return h.Div(h.ID(c.id), f()) }
 }
 
-// Component registers a sub context that is self contained self contained with it's own
+// Component registers a sub context that has self contained data, actions and signals.
-// view, state actions and signals and returns the DOM node that can be added to the view
+// It returns the component's view as a DOM node fn that can be placed in the view
-// of the parent.
+// of the parent. Components can be added to components.
+//
+// Example:
+//
+//	counterComponent := func(c *via.Context) {
+//		count := 0
+//		step := c.Signal(1)
+//
+//		increment := c.Action(func() {
+//			count += step.Int()
+//			c.Sync()
+//		})
+//
+//		c.View(func() h.H {
+//			return h.Div(
+//				h.P(h.Textf("Count: %d", count)),
+//				h.P(h.Span(h.Text("Step: ")), h.Span(step.Text())),
+//				h.Label(
+//					h.Text("Update Step: "),
+//					h.Input(h.Type("number"), step.Bind()),
+//				),
+//				h.Button(h.Text("Increment"), increment.OnClick()),
+//			)
+//		})
+//	})
+//
+//	v.Page("/", func(c *via.Context) {
+//		counter1 := c.Component(counterComponent)
+//		counter2 := c.Component(counterComponent)
+//
+//		c.View(func() h.H {
+//			return h.Div(
+//				h.H1(h.Text("Counter 1")),
+//				counter1(),
+//				h.H1(h.Text("Counter 2")),
+//				counter2(),
+//			)
+//		})
+//	})
 func (c *Context) Component(f func(c *Context)) func() h.H {
 	id := c.id + "/_component/" + genRandID()
 	compCtx := newContext(id, c.app)
+	if c.isComponent() {
+		compCtx.parentPageCtx = c.parentPageCtx
+	} else {
+		compCtx.parentPageCtx = c
+	}
 	f(compCtx)
-	compCtx.sse = c.sse
+	c.componentRegistry[id] = compCtx
-	// c.componentsMux.Lock()
-	// defer c.componentsMux.Unlock()
-	//
-	// c.components[id] = compCtx
-	c.app.contextRegistryMutex.Lock()
-	defer c.app.contextRegistryMutex.Unlock()
-	c.app.contextRegistry[id] = compCtx
-
 	return compCtx.view
 }
 
+func (c *Context) isComponent() bool {
+	return c.parentPageCtx != nil
+}
+
 // Action registers an event handler and returns a trigger to that event that
 // that can be added to the view fn as any other via.h element.
 //
@@ -77,15 +116,17 @@ func (c *Context) Component(f func(c *Context)) func() h.H {
 //		 )
 //	})
 func (c *Context) Action(f func()) *actionTrigger {
-	// if id == "" {
-	// 	c.app.logErr(c, "failed to bind action to context: id is ''")
-	// }
 	id := genRandID()
 	if f == nil {
 		c.app.logErr(c, "failed to bind action '%s' to context: nil func", id)
 		return nil
 	}
-	c.actionRegistry[id] = f
+
+	if c.isComponent() {
+		c.parentPageCtx.actionRegistry[id] = f
+	} else {
+		c.actionRegistry[id] = f
+	}
 	return &actionTrigger{id}
 }
 
@@ -137,7 +178,13 @@ func (c *Context) Signal(v any) *signal {
 		t:       reflect.TypeOf(v),
 		changed: true,
 	}
-	c.signals[sigID] = sig
+
+	// components register signals on parent page
+	if c.isComponent() {
+		c.parentPageCtx.signals[sigID] = sig
+	} else {
+		c.signals[sigID] = sig
+	}
 	return sig
 
 }
@@ -159,15 +206,22 @@ func (c *Context) injectSignals(sigs map[string]any) {
 // Sync pushes the current view state and signal changes to the browser immediately
 // over the live SSE event stream.
 func (c *Context) Sync() {
-	if c.sse == nil {
+	// components use parent page sse stream
-		c.app.logErr(c, "sync view failed: no sse connection")
+	var sse *datastar.ServerSentEventGenerator
+	if c.isComponent() {
+		sse = c.parentPageCtx.sse
+	} else {
+		sse = c.sse
+	}
+	if sse == nil {
+		c.app.logErr(c, "sync view failed: inactive SSE stream")
 	}
 	elemsPatch := bytes.NewBuffer(make([]byte, 0))
 	if err := c.view().Render(elemsPatch); err != nil {
 		c.app.logErr(c, "sync view failed: %v", err)
 		return
 	}
-	_ = c.sse.PatchElements(elemsPatch.String())
+	_ = sse.PatchElements(elemsPatch.String())
 	updatedSigs := make(map[string]any)
 	for id, sig := range c.signals {
 		if sig.err != nil {
@@ -178,7 +232,7 @@ func (c *Context) Sync() {
 		}
 	}
 	if len(updatedSigs) != 0 {
-		_ = c.sse.MarshalAndPatchSignals(updatedSigs)
+		_ = sse.MarshalAndPatchSignals(updatedSigs)
 	}
 }
 
@@ -200,7 +254,13 @@ func (c *Context) Sync() {
 // Then, the merge will only occur if the ID of the top level element in the patch
 // matches 'my-element'.
 func (c *Context) SyncElements(elem h.H) {
-	if c.sse == nil {
+	var sse *datastar.ServerSentEventGenerator
+	if c.isComponent() {
+		sse = c.parentPageCtx.sse
+	} else {
+		sse = c.sse
+	}
+	if sse == nil {
 		c.app.logErr(c, "sync element failed: no sse connection")
 	}
 	if c.view == nil {
@@ -213,13 +273,19 @@ func (c *Context) SyncElements(elem h.H) {
 	}
 	b := bytes.NewBuffer(make([]byte, 0))
 	_ = elem.Render(b)
-	c.sse.PatchElements(b.String())
+	_ = sse.PatchElements(b.String())
 }
 
 // SyncSignals pushes the current signal changes to the browser immediately
 // over the live SSE event stream.
 func (c *Context) SyncSignals() {
-	if c.sse == nil {
+	var sse *datastar.ServerSentEventGenerator
+	if c.isComponent() {
+		sse = c.parentPageCtx.sse
+	} else {
+		sse = c.sse
+	}
+	if sse == nil {
 		c.app.logErr(c, "sync signals failed: sse connection not found")
 	}
 	updatedSigs := make(map[string]any)
@@ -232,7 +298,7 @@ func (c *Context) SyncSignals() {
 		}
 	}
 	if len(updatedSigs) != 0 {
-		_ = c.sse.MarshalAndPatchSignals(updatedSigs)
+		_ = sse.MarshalAndPatchSignals(updatedSigs)
 	}
 }
 
@@ -242,11 +308,11 @@ func newContext(id string, a *via) *Context {
 	}
 
 	return &Context{
-		id:             id,
+		id:                id,
-		app:            a,
+		app:               a,
-		components:     make(map[string]*Context),
+		componentRegistry: make(map[string]*Context),
-		actionRegistry: make(map[string]func()),
+		actionRegistry:    make(map[string]func()),
-		signals:        make(map[string]*signal),
+		signals:           make(map[string]*signal),
-		createdAt:      time.Now(),
+		createdAt:         time.Now(),
 	}
 }

internal/examples/countercomp/main.go

@@ -9,13 +9,15 @@ func main() {
 	v := via.New()
 
 	v.Page("/", func(c *via.Context) {
-		counter1 := c.Component(counterComponent)
+		counterComp1 := c.Component(counterCompFn)
-		counter2 := c.Component(counterComponent)
+		counterComp2 := c.Component(counterCompFn)
 
 		c.View(func() h.H {
 			return h.Div(
-				counter1(),
+				h.H1(h.Text("Counter 1")),
-				counter2(),
+				counterComp1(),
+				h.H1(h.Text("Counter 2")),
+				counterComp2(),
 			)
 		})
 	})
@@ -23,22 +25,18 @@ func main() {
 	v.Start(":3000")
 }
 
-type Counter struct{ Count int }
+func counterCompFn(c *via.Context) {
-
+	count := 0
-func counterComponent(c *via.Context) {
-
-	s := Counter{Count: 0}
-
 	step := c.Signal(1)
 
 	increment := c.Action(func() {
-		s.Count += step.Int()
+		count += step.Int()
 		c.Sync()
 	})
 
 	c.View(func() h.H {
 		return h.Div(
-			h.P(h.Textf("Count: %d", s.Count)),
+			h.P(h.Textf("Count: %d", count)),
 			h.P(h.Span(h.Text("Step: ")), h.Span(step.Text())),
 			h.Label(
 				h.Text("Update Step: "),
@@ -48,48 +46,3 @@ func counterComponent(c *via.Context) {
 		)
 	})
 }
-
-//
-// c.View(func() h.H {
-// 	return Layout(
-// 		h.Div(
-// 			h.Meta(h.Data("init", "@get('/_sse')")),
-// 			h.P(h.Data("text", "$via-ctx")),
-// 			h.Div(
-// 				counter(),
-// 				h.Data("signals:step", "1"),
-// 				h.Label(h.Text("Step")),
-// 				h.Input(h.Data("bind", "step")),
-// 				h.Button(
-// 					h.Text("Trigger foo"),
-// 					h.Data("on:click", "@get('/_action/foo')"),
-// 				),
-// 			),
-// 		),
-// 	)
-// })
-
-// conterComponent := c.Component("counter1", CounterComponent)
-//
-// in c.View of page add CounterComponent
-//
-// func CounterComponent(c *via.Context){
-// 	s := CounterState{ Count: 1 }
-// 	step := c.Signal(1)
-//
-// 	c.View(func() h.H {
-// 		return h.Div(
-// 			h.P(h.Textf("Count: %d", s.Count)),
-// 			h.Label(
-// 				h.Text("Step"),
-// 				h.Input(h.Type("number"), step.Bind()),
-// 			),
-// 			h.Button(h.Text("Increment"), h.OnClick("inc")),
-// 		)
-// 	})
-//
-// 	c.Action("inc", func() {
-// 		s.Count += step
-// 		c.Sync()
-// 	})
-// }

via.go

@@ -99,11 +99,6 @@ func (v *via) Page(route string, composeContext func(c *Context)) {
 		v.logDebug(c, "GET %s", route)
 		composeContext(c)
 		v.registerCtx(c.id, c)
-		// viewFn := c.view
-		// viewFnWithID := func() h.H {
-		// 	return h.Div(h.ID(c.id), viewFn())
-		// }
-		// c.view = viewFnWithID
 		view := v.baseLayout(h.HTML5Props{
 			Head: []h.H{
 				h.Meta(h.Data("signals", fmt.Sprintf("{'via-ctx':'%s'}", id))),
@@ -180,7 +175,6 @@ func New() *via {
 		var sigs map[string]any
 		_ = datastar.ReadSignals(r, &sigs)
 		cID, _ := sigs["via-ctx"].(string)
-		app.logDebug(nil, "GET /_action/%s via-ctx=%s", actionID, cID)
 		active_ctx_count := 0
 		inactive_ctx_count := 0
 		for _, c := range app.contextRegistry {