LiveReload

internal/examples/livereload/.air.toml

@@ -0,0 +1,46 @@
+root = "."
+testdata_dir = "testdata"
+tmp_dir = "tmp"
+
+[build]
+  args_bin = []
+  bin = "./tmp/main"
+  cmd = "go build -o ./tmp/main ."
+  delay = 1000
+  exclude_dir = ["assets", "tmp", "vendor", "testdata"]
+  exclude_file = []
+  exclude_regex = ["_test.go"]
+  exclude_unchanged = false
+  follow_symlink = false
+  full_bin = ""
+  include_dir = []
+  include_ext = ["go", "tpl", "tmpl", "html"]
+  include_file = []
+  kill_delay = "0s"
+  log = "build-errors.log"
+  poll = false
+  poll_interval = 0
+  post_cmd = []
+  pre_cmd = []
+  rerun = false
+  rerun_delay = 500
+  send_interrupt = false
+  stop_on_error = false
+
+[color]
+  app = ""
+  build = "yellow"
+  main = "magenta"
+  runner = "green"
+  watcher = "cyan"
+
+[log]
+  main_only = false
+  time = false
+
+[misc]
+  clean_on_exit = false
+
+[screen]
+  clear_on_rebuild = false
+  keep_scroll = true

internal/examples/livereload/.gitignore

@@ -0,0 +1,2 @@
+tmp/
+build-errors.log

internal/examples/livereload/README.md

@@ -0,0 +1,28 @@
+# Live Reload with Air
+
+Hot-reloads your Go code and web page.
+
+## Setup
+
+If you don't have Air yet:
+```bash
+go install github.com/air-verse/air@latest
+```
+
+## Run
+```bash
+air
+```
+
+Then open `http://localhost:3000` in your browser.
+
+## How It Works
+
+Air watches your Go files and rebuilds when you make changes.
+
+LiveReloadPlugin handles browser refresh through a SSE connection at `/dev/reload`. When Air restarts the server, the connection drops, triggering an automatic page reload after 100ms. This only runs on localhost.
+
+## Files
+
+- `.air.toml` - Air config
+- `livereload.go` - Via plugin for browser auto-reload

internal/examples/livereload/livereload.go

@@ -0,0 +1,57 @@
+package main
+
+import (
+	"net/http"
+
+	"github.com/go-via/via"
+	"github.com/go-via/via/h"
+)
+
+func LiveReloadPlugin(v *via.V) {
+	v.HandleFunc("GET /dev/reload", func(w http.ResponseWriter, r *http.Request) {
+		w.Header().Set("Content-Type", "text/event-stream")
+		w.Header().Set("Cache-Control", "no-cache")
+		w.Header().Set("Connection", "keep-alive")
+		w.Header().Set("Access-Control-Allow-Origin", "*")
+
+		<-r.Context().Done()
+	})
+}
+
+func liveReloadScript() h.H {
+	return h.Script(h.Raw(`
+if (window.location.hostname === 'localhost' || window.location.hostname === '127.0.0.1') {
+  const evtSource = new EventSource('/dev/reload');
+  let overlay = null;
+  let showTimer = null;
+  
+  evtSource.onerror = () => {
+    evtSource.close();
+    
+    showTimer = setTimeout(() => {
+      if (!overlay) {
+        overlay = document.createElement('div');
+        overlay.style.cssText = 'position: fixed; top: 50%; left: 50%; transform: translate(-50%, -50%); background: rgba(200, 200, 200, 0.95); padding: 20px 40px; border-radius: 8px; color: #333; font-size: 24px; z-index: 999999; font-family: -apple-system, sans-serif;';
+        overlay.textContent = '🔌 Reconnecting...';
+        document.body.appendChild(overlay);
+      }
+    }, 1000);
+    
+    (async function poll() {
+      for (let i = 0; i < 100; i++) {
+        try {
+          const res = await fetch('/', { method: 'HEAD', signal: AbortSignal.timeout(1000) });
+          if (res.ok) {
+            clearTimeout(showTimer);
+            if (overlay) overlay.remove();
+            location.reload();
+            return;
+          }
+        } catch (e) {}
+        await new Promise(r => setTimeout(r, 50));
+      }
+    })();
+  };
+}
+`))
+}

internal/examples/livereload/main.go

@@ -0,0 +1,46 @@
+package main
+
+import (
+	"github.com/go-via/via"
+	"github.com/go-via/via/h"
+)
+
+type Counter struct{ Count int }
+
+func main() {
+	v := via.New()
+
+	LiveReloadPlugin(v)
+
+	v.Config(via.Options{
+		DocumentTitle: "Live Reload",
+		DocumentHeadIncludes: []h.H{
+			liveReloadScript(),
+		},
+	})
+
+	v.Page("/", func(c *via.Context) {
+		data := Counter{Count: 0}
+		step := c.Signal(1)
+
+		increment := c.Action(func() {
+			data.Count += step.Int()
+			c.Sync()
+		})
+
+		c.View(func() h.H {
+			return h.Div(h.Class("container"),
+				h.H1(h.Text("Live Reload")),
+				h.P(h.Textf("Count: %d", data.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.Start(":3000")
+}

signal.go

@@ -35,7 +35,7 @@ func (s *signal) Err() error {
 	return s.err
 }
 
-// Bind binds this signal to an imput element. When the imput changes
+// Bind binds this signal to an input element. When the input changes
 // its value the signal updates in real-time in the browser.
 //
 // Example:

via.go

@@ -75,6 +75,9 @@ func (v *V) Config(cfg Options) {
 	if cfg.LogLvl != v.cfg.LogLvl {
 		v.cfg.LogLvl = cfg.LogLvl
 	}
+	if cfg.DocumentTitle != "" {
+		v.cfg.DocumentTitle = cfg.DocumentTitle
+	}
 	if cfg.DocumentHeadIncludes != nil {
 		v.cfg.DocumentHeadIncludes = cfg.DocumentHeadIncludes
 	}
@@ -142,6 +145,8 @@ func (v *V) registerCtx(id string, c *Context) {
 // }
 
 func (v *V) getCtx(id string) (*Context, error) {
+	v.contextRegistryMutex.RLock()
+	defer v.contextRegistryMutex.RUnlock()
 	if c, ok := v.contextRegistry[id]; ok {
 		return c, nil
 	}