Files
via/internal/examples/spa/main.go
Ryan Hamamura 27b8540b71 feat: add SPA navigation with view transitions
Swap page content over the existing SSE connection without full page
loads. A persistent Context resets its page-specific state (signals,
actions, intervals, subscriptions) on navigate while preserving the
SSE stream, CSRF token, and session.

- c.Navigate(path) for programmatic SPA navigation from actions
- Injected JS intercepts same-origin <a> clicks (opt out with
  data-via-no-boost) and handles popstate for back/forward
- v.Layout() wraps pages in a shared shell for DRY nav/chrome
- View Transition API integration via WithViewTransitions() on
  PatchElements and h.DataViewTransition() helper
- POST /_navigate endpoint with CSRF validation and rate limiting
- pageStopChan cancels page-level OnInterval goroutines on navigate
- Includes SPA example with layout, counter, and live clock pages
2026-02-12 13:52:47 -10:00

92 lines
2.7 KiB
Go

package main
import (
"fmt"
"time"
"github.com/ryanhamamura/via"
. "github.com/ryanhamamura/via/h"
)
func main() {
v := via.New()
v.Config(via.Options{
DocumentTitle: "SPA Navigation",
ServerAddress: ":7331",
})
v.AppendToHead(
Raw(`<link rel="preconnect" href="https://fonts.googleapis.com">`),
Raw(`<link rel="preconnect" href="https://fonts.gstatic.com" crossorigin>`),
Raw(`<link href="https://fonts.googleapis.com/css2?family=Inter:wght@400;600;700&display=swap" rel="stylesheet">`),
Raw(`<style>body{font-family:'Inter',sans-serif;margin:0;background:#111;color:#eee}</style>`),
)
v.Layout(func(content func() H) H {
return Div(
Nav(
Style("display:flex;gap:1rem;padding:1rem;background:#222;"),
A(Href("/"), Text("Home"), Style("color:#fff")),
A(Href("/counter"), Text("Counter"), Style("color:#fff")),
A(Href("/clock"), Text("Clock"), Style("color:#fff")),
A(Href("https://github.com"), Text("GitHub (external)"), Style("color:#888")),
A(Href("/"), Text("Full Reload"), Attr("data-via-no-boost"), Style("color:#f88")),
),
Main(Style("padding:1rem"), content()),
)
})
// Home page
v.Page("/", func(c *via.Context) {
goCounter := c.Action(func() { c.Navigate("/counter", false) })
c.View(func() H {
return Div(
H1(Text("Home"), DataViewTransition("page-title")),
P(Text("Click the nav links above — no page reload, no white flash.")),
P(Text("Or navigate programmatically:")),
Button(Text("Go to Counter"), goCounter.OnClick()),
)
})
})
// Counter page — demonstrates signals and actions survive within a page,
// but reset on navigate away and back.
v.Page("/counter", func(c *via.Context) {
count := 0
increment := c.Action(func() { count++; c.Sync() })
goHome := c.Action(func() { c.Navigate("/", false) })
c.View(func() H {
return Div(
H1(Text("Counter"), DataViewTransition("page-title")),
P(Textf("Count: %d", count)),
Button(Text("+1"), increment.OnClick()),
Button(Text("Go Home"), goHome.OnClick(), Style("margin-left:0.5rem")),
)
})
})
// Clock page — demonstrates OnInterval cleanup on navigate.
v.Page("/clock", func(c *via.Context) {
now := time.Now().Format("15:04:05")
c.OnInterval(time.Second, func() {
now = time.Now().Format("15:04:05")
c.Sync()
})
c.View(func() H {
return Div(
H1(Text("Clock"), DataViewTransition("page-title")),
P(Text("This page has an OnInterval that ticks every second.")),
P(Textf("Current time: %s", now)),
P(Text("Navigate away and back — the old interval stops, a new one starts.")),
P(Textf("Proof this is a fresh page init: random = %d", time.Now().UnixNano()%1000)),
)
})
})
fmt.Println("SPA example running at http://localhost:7331")
v.Start()
}