Live update Reveal config

cmd/goveal/serve.go

@@ -51,8 +51,8 @@ var (
 			hub := events.NewEventHub(
 				wdfs,
 				fnv.New32a(),
-				events.FileNameTrigger(args[0]),
+				events.MutationReloadForFile(args[0]),
-				events.FileNameTrigger(filepath.Base(cfg.ConfigFileInUse)),
+				events.MutationConfigReloadForFile(filepath.Base(cfg.ConfigFileInUse)),
 			)
 
 			api.NoCache(app)

config/components.go

@@ -3,9 +3,10 @@ package config
 var (
 	defaults = map[string]interface{}{
 		"mermaid.theme":                       "forest",
-		"reveal.theme":                        "beige",
+		"theme":                               "beige",
 		"codeTheme":                           "monokai",
 		"transition":                          TransitionNone,
+		"controlsLayout":                      ControlsLayoutEdges,
 		"controls":                            true,
 		"progress":                            true,
 		"history":                             true,
@@ -23,10 +24,14 @@ const (
 	TransitionConvex  Transition = "convex"
 	TransitionConcave Transition = "concave"
 	TransitionZoom    Transition = "zoom"
+
+	ControlsLayoutBottomRight ControlsLayout = "bottom-right"
+	ControlsLayoutEdges       ControlsLayout = "edges"
 )
 
 type (
 	Transition     string
+	ControlsLayout string
 	Mermaid        struct {
 		Theme string `json:"theme"`
 	}
@@ -40,6 +45,7 @@ type (
 		CodeTheme      string         `json:"codeTheme"`
 		Transition     Transition     `json:"transition"`
 		Controls       bool           `json:"controls"`
+		ControlsLayout ControlsLayout `json:"controlsLayout"`
 		Progress       bool           `json:"progress"`
 		History        bool           `json:"history"`
 		Center         bool           `json:"center"`

events/event_hub.go

@@ -21,14 +21,15 @@ const (
 )
 
 type (
-	ReloadTrigger interface {
+	EventMutation interface {
-		Triggers(ev fs.Event) bool
+		OnEvent(in ContentEvent, ev fs.Event) (out ContentEvent)
 	}
 	ContentEvent struct {
 		File         string `json:"file"`
 		FileNameHash string `json:"fileNameHash"`
 		Timestamp    string `json:"ts"`
 		ForceReload  bool   `json:"forceReload"`
+		ReloadConfig bool   `json:"reloadConfig"`
 	}
 	EventSource interface {
 		io.Closer
@@ -43,27 +44,32 @@ type (
 		EventHandler
 		OnError chan error
 	}
-	FileNameTrigger   string
+	MutationReloadForFile       string
-	FileSuffixTrigger string
+	MutationConfigReloadForFile string
 )
 
-func (t FileNameTrigger) Triggers(ev fs.Event) bool {
+func (t MutationReloadForFile) OnEvent(in ContentEvent, ev fs.Event) (out ContentEvent) {
-	fileBase := filepath.Base(ev.File)
+	if strings.EqualFold(filepath.Base(ev.File), string(t)) {
-	return strings.EqualFold(fileBase, string(t))
+		in.ForceReload = true
+	}
+	return in
 }
 
-func (t FileSuffixTrigger) Triggers(ev fs.Event) bool {
+func (t MutationConfigReloadForFile) OnEvent(in ContentEvent, ev fs.Event) (out ContentEvent) {
-	return strings.HasSuffix(strings.ToLower(filepath.Base(ev.File)), strings.ToLower(string(t)))
+	if strings.EqualFold(filepath.Base(ev.File), string(t)) {
+		in.ReloadConfig = true
+	}
+	return in
 }
 
 func (f EventHandlerFunc) OnEvent(ev ContentEvent) error {
 	return f(ev)
 }
 
-func NewEventHub(eventSource EventSource, fileNameHash hash.Hash, triggers ...ReloadTrigger) *EventHub {
+func NewEventHub(eventSource EventSource, fileNameHash hash.Hash, mutations ...EventMutation) *EventHub {
 	hub := &EventHub{
 		FileNameHash:  fileNameHash,
-		reloadTriggers: triggers,
+		mutations:     mutations,
 		source:        eventSource,
 		subscriptions: make(map[uuid.UUID]*subscription),
 		done:          make(chan struct{}),
@@ -76,7 +82,7 @@ func NewEventHub(eventSource EventSource, fileNameHash hash.Hash, triggers ...Re
 
 type EventHub struct {
 	FileNameHash  hash.Hash
-	reloadTriggers []ReloadTrigger
+	mutations     []EventMutation
 	lock          sync.RWMutex
 	done          chan struct{}
 	source        EventSource
@@ -129,20 +135,16 @@ func (h *EventHub) notifySubscribers(ev fs.Event) {
 	h.lock.RLock()
 	defer h.lock.RUnlock()
 
-	var triggerReload bool
-	for idx := range h.reloadTriggers {
-		if triggerReload = h.reloadTriggers[idx].Triggers(ev); triggerReload {
-			break
-		}
-	}
-
 	ce := ContentEvent{
 		File:         fmt.Sprintf("/%s", ev.File),
 		Timestamp:    strconv.FormatInt(ev.Timestamp.Unix(), baseDecimal),
-		ForceReload:  triggerReload,
 		FileNameHash: hex.EncodeToString(h.FileNameHash.Sum([]byte(path.Base(ev.File)))),
 	}
 
+	for idx := range h.mutations {
+		ce = h.mutations[idx].OnEvent(ce, ev)
+	}
+
 	for _, handler := range h.subscriptions {
 		if err := handler.OnEvent(ce); err != nil {
 			handler.OnError <- err

examples/goveal.yaml

@@ -3,6 +3,16 @@ codeTheme: monokai
 horizontalSeparator: ===
 verticalSeparator: ---
 transition: convex
-menu.numbers: false
+controlsLayout: edges
+controls: true
+progress: true
+history: true
+center: true
+slideNumber: true
+menu:
+  numbers: false
+  useTextContentForMissingTitles: true
+mermaid:
+  theme: forest
 stylesheets:
   - custom.css

web/js/app.js

@@ -25,9 +25,13 @@ async function setSlidesContent() {
     document.getElementById("content-root").innerHTML = contentDocument.documentElement.innerHTML
 }
 
-async function initReveal() {
+async function getRevealConfig() {
     let resp = await fetch('/api/v1/config/reveal')
-    let cfg = await resp.json()
+    return await resp.json()
+}
+
+async function initReveal() {
+    let cfg = await getRevealConfig()
     Reveal.initialize({
         controls: cfg.controls,
         progress: cfg.progress,
@@ -97,9 +101,16 @@ function subscribeToEvents() {
     source.onmessage = (ev => {
         let obj = JSON.parse(ev.data);
         console.log(obj);
-        if (obj.forceReload) {
+        switch (true) {
+            case obj.forceReload:
                 window.location.reload()
-        } else {
+                break
+            case obj.reloadConfig:
+                getRevealConfig().then(cfg => {
+                    Reveal.configure(cfg)
+                })
+                break
+            default:
                 switch (true) {
                     case obj.file.endsWith(".css"):
                         let cssLink = document.querySelector(`link[rel=stylesheet][id="${obj.fileNameHash}"]`);