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Markk116
2026-03-08 17:22:13 +01:00
parent 6605bf452f
commit 71e63e4410
3 changed files with 95 additions and 144 deletions
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examples/todo/about.rs
+1 -1
View File
@@ -16,7 +16,7 @@ pub async fn about(_cx: &mut RenderContext) -> anyhow::Result<Markup> {
nav {
button.nav-link
data-on-click="$tree = {page: 'TodoList'}; @post('/render')" {
data-on:click="$tree = {page: 'TodoList'}; @post('/render')" {
"Todos"
}
" | "
examples/todo/app.rs
+88 -137
View File
@@ -1,23 +1,19 @@
use livevue_rs::{
AppState, CacheKey, ComponentTree, RenderContext, SharedState, SignalStore,
format_patch_elements, format_patch_signals, sse_handler,
format_patch_elements, sse_handler,
};
use axum::extract::{Query as AxumQuery, State};
use axum::http::header;
use axum::response::{Html, IntoResponse};
use axum::routing::{get, post};
use axum::{Json, Router};
use axum::http::StatusCode;
use uuid::Uuid;
// ---------------------------------------------------------------------------
// Router
// ---------------------------------------------------------------------------
/// Build the axum Router with all routes.
///
/// Lesson from v0.0: handlers live here next to the components they call,
/// not in a separate routes.rs with complex trait object signatures.
pub fn router(state: SharedState) -> Router {
Router::new()
.route("/", get(initial_page_load))
@@ -34,27 +30,13 @@ pub fn router(state: SharedState) -> Router {
// Document shell
// ---------------------------------------------------------------------------
/// Wrap rendered component HTML in a full HTML document.
/// Full HTML document for initial page load.
///
/// Lesson from v0.0: Maud can't handle DataStar's attribute syntax
/// (e.g. `data-on-signal-change__debounce.300ms`). The document shell uses
/// format! / raw string. Maud is for component interiors only.
///
/// DataStar v1 contract (verified against https://data-star.dev/reference):
/// DataStar v1 contract:
/// - `data-signals` — initialize signals (JS object literal syntax)
/// - `data-on-signal-patch` — fires when any signal is patched (renamed from
/// `data-on-signal-change` which was removed in RC8)
/// - `__debounce.300ms` — modifier: debounce 300ms
/// - `@post('/render')` — send all non-_ signals as JSON body
/// - `@get('/sse?conn=...')` — open long-lived SSE pipe
/// - `data-on-load` — fires when element enters DOM
///
/// KNOWN v0 QUIRK: Nav buttons use `$tree = {...}; @post('/render')`,
/// which fires an immediate POST. The signal change handler then fires a
/// second debounced POST 300ms later. This double-fire is harmless (same
/// HTML both times) but wasteful. Phase 2 could fix this with request
/// deduplication or by switching nav to only mutate the signal and relying
/// solely on the auto-poster.
/// - `data-on-signal-patch__debounce.300ms` — fires when any signal is patched,
/// debounced 300ms, posts all non-_ signals as JSON body to /render
/// - `data-init` — fires when element enters DOM, opens long-lived SSE pipe
fn document_shell(conn_id: Uuid, initial_signals: &str, inner_html: &str) -> String {
format!(
r#"<!DOCTYPE html>
@@ -69,16 +51,29 @@ fn document_shell(conn_id: Uuid, initial_signals: &str, inner_html: &str) -> Str
</style>
</head>
<body>
<div id="app"
data-signals='{signals}'
data-on-signal-patch__debounce.300ms="@post('/render')"
data-on-load="@get('/sse?conn={conn}')">
{inner}
</div>
{app}
</body>
</html>"#,
css = INLINE_CSS,
signals = initial_signals,
app = app_wrapper(conn_id, initial_signals, inner_html),
)
}
/// The `<div id="app">` wrapper with DataStar bindings.
///
/// Extracted separately so `/render` can return just this element as
/// `text/html` — DataStar morphs it into the existing DOM by id.
fn app_wrapper(conn_id: Uuid, signals: &str, inner_html: &str) -> String {
format!(
r#"<div id="app"
data-signals='{signals}'
data-on-signal-patch="@post('/render')"
data-on-init="@get('/sse?conn={conn}')">
{inner}
<pre data-json-signals></pre>
</div>"#,
// Could __debounce.300ms on the signal patch
signals = signals,
conn = conn_id,
inner = inner_html,
)
@@ -109,10 +104,6 @@ const INLINE_CSS: &str = r#"
// Page resolution
// ---------------------------------------------------------------------------
/// Match a page name (from the `tree` signal) to its component function.
///
/// This is a plain match statement — no ComponentRegistry, no trait objects,
/// no async lifetime gymnastics. The right call for a v0 with two pages.
async fn resolve_and_render(cx: &mut RenderContext) -> anyhow::Result<String> {
let markup = match cx.tree.page.as_str() {
"TodoList" => crate::todo_list::todo_list(cx).await?,
@@ -131,9 +122,7 @@ async fn resolve_and_render(cx: &mut RenderContext) -> anyhow::Result<String> {
Ok(markup.into_string())
}
/// Shared render pipeline used by both initial page load and POST /render.
///
/// Returns `(rendered_html, subscription_keys, signals_json)`.
/// Shared render pipeline. Returns `(rendered_inner_html, subscription_keys, signals_json)`.
async fn render_page(
db: &sqlx::SqlitePool,
conn_id: Uuid,
@@ -147,6 +136,22 @@ async fn render_page(
Ok((html, keys, signals_json))
}
/// Extract conn_id and tree from a signal store.
fn extract_conn_and_tree(signals: &SignalStore) -> (Uuid, ComponentTree) {
let conn_id = signals
.get("connId")
.and_then(|v| v.as_str())
.and_then(|s| s.parse().ok())
.unwrap_or_else(Uuid::new_v4);
let tree = signals
.get("tree")
.and_then(|v| serde_json::from_value(v.clone()).ok())
.unwrap_or_default();
(conn_id, tree)
}
// ---------------------------------------------------------------------------
// Handlers
// ---------------------------------------------------------------------------
@@ -155,7 +160,6 @@ async fn render_page(
async fn initial_page_load(State(state): State<SharedState>) -> impl IntoResponse {
let conn_id = Uuid::new_v4();
// Build initial signals
let tree = ComponentTree {
page: "TodoList".into(),
..Default::default()
@@ -170,7 +174,6 @@ async fn initial_page_load(State(state): State<SharedState>) -> impl IntoRespons
match render_page(&state.db, conn_id, signals, tree).await {
Ok((html, _keys, _signals_json)) => {
// Keys and signals_json are stored when SSE connects
Html(document_shell(conn_id, &initial_signals_attr, &html))
}
Err(e) => Html(document_shell(
@@ -210,52 +213,27 @@ async fn initial_about_load(State(state): State<SharedState>) -> impl IntoRespon
/// `POST /render` — Signal-triggered rerender.
///
/// DataStar sends all non-`_` signals as JSON body when any signal changes
/// (triggered by `data-on-signal-patch` + `@post('/render')`).
///
/// Returns `Content-Type: text/event-stream` with a single
/// `datastar-patch-elements` event containing the full page HTML.
/// DataStar sends all non-`_` signals as JSON body on every signal patch.
/// Returns `text/html` with the full `<div id="app">` wrapper — DataStar
/// morphs it into the existing DOM by matching the element id.
async fn render_handler(
State(state): State<SharedState>,
Json(body): Json<serde_json::Value>,
) -> impl IntoResponse {
let signals = SignalStore::from_json(body);
let (conn_id, tree) = extract_conn_and_tree(&signals);
// Extract connection id
let conn_id: Uuid = signals
.get("connId")
.and_then(|v| v.as_str())
.and_then(|s| s.parse().ok())
.unwrap_or_else(Uuid::new_v4);
// Extract component tree
let tree: ComponentTree = signals
.get("tree")
.and_then(|v| serde_json::from_value(v.clone()).ok())
.unwrap_or_default();
match render_page(&state.db, conn_id, signals, tree).await {
match render_page(&state.db, conn_id, signals.clone(), tree).await {
Ok((html, keys, signals_json)) => {
// Update connection state
state.connections.update_signals(&conn_id, signals_json);
state.connections.update_signals(&conn_id, signals_json.clone());
state.subscriptions.update(conn_id, keys);
let sse_body = format_patch_elements(&html);
(
[(header::CONTENT_TYPE, "text/event-stream")],
sse_body,
)
.into_response()
}
Err(e) => {
let error_html = format!(r#"<div id="app"><p>Render error: {}</p></div>"#, e);
let sse_body = format_patch_elements(&error_html);
(
[(header::CONTENT_TYPE, "text/event-stream")],
sse_body,
)
.into_response()
Html(app_wrapper(conn_id, &signals_json, &html))
}
Err(e) => Html(app_wrapper(
conn_id,
&signals.to_json_string(),
&format!("<p>Render error: {}</p>", e),
)),
}
}
@@ -265,73 +243,43 @@ struct ActionIdParams {
id: i64,
}
/// Helper: extract common fields from signal body, run a mutation, then rerender.
/// Helper: run a mutation, push the rerendered page down the SSE pipe, return 200.
///
/// Returns an SSE response with the rerendered page.
async fn action_then_render(
/// Actions do not return a body — the result comes down the SSE pipe as a
/// `datastar-patch-elements` event.
async fn action_then_push(
state: &AppState,
body: serde_json::Value,
signals: SignalStore,
mutation: impl std::future::Future<Output = anyhow::Result<()>> + Send,
patch_signals: Option<&str>,
) -> impl IntoResponse {
let signals = SignalStore::from_json(body);
) -> StatusCode {
let (conn_id, tree) = extract_conn_and_tree(&signals);
let conn_id: Uuid = signals
.get("connId")
.and_then(|v| v.as_str())
.and_then(|s| s.parse().ok())
.unwrap_or_else(Uuid::new_v4);
let tree: ComponentTree = signals
.get("tree")
.and_then(|v| serde_json::from_value(v.clone()).ok())
.unwrap_or_default();
// Run the mutation
if let Err(e) = mutation.await {
let error_html = format!(r#"<div id="app"><p>Action error: {}</p></div>"#, e);
return (
[(header::CONTENT_TYPE, "text/event-stream")],
format_patch_elements(&error_html),
)
.into_response();
eprintln!("Action error for {}: {}", conn_id, e);
return StatusCode::INTERNAL_SERVER_ERROR;
}
// Rerender
match render_page(&state.db, conn_id, signals, tree).await {
Ok((html, keys, signals_json)) => {
state.connections.update_signals(&conn_id, signals_json);
state.connections.update_signals(&conn_id, signals_json.clone());
state.subscriptions.update(conn_id, keys);
let mut sse_body = String::new();
// Optionally patch signals (e.g. clear the input)
if let Some(ps) = patch_signals {
sse_body.push_str(&format_patch_signals(ps));
if let Some(sender) = state.connections.get_sender(&conn_id) {
let event = format_patch_elements(&app_wrapper(conn_id, &signals_json, &html));
// Non-blocking: if the pipe is closed the cleanup task handles it
let _ = sender.try_send(event);
}
sse_body.push_str(&format_patch_elements(&html));
(
[(header::CONTENT_TYPE, "text/event-stream")],
sse_body,
)
.into_response()
StatusCode::OK
}
Err(e) => {
let error_html = format!(r#"<div id="app"><p>Render error: {}</p></div>"#, e);
(
[(header::CONTENT_TYPE, "text/event-stream")],
format_patch_elements(&error_html),
)
.into_response()
eprintln!("Render error for {}: {}", conn_id, e);
StatusCode::INTERNAL_SERVER_ERROR
}
}
}
/// `POST /action/add_todo` — Create a new todo, then rerender.
///
/// Reads the `newTodo` signal from the POST body, inserts it, and sends
/// back a `datastar-patch-signals` event to clear the input followed by
/// a `datastar-patch-elements` event with the rerendered page.
/// `POST /action/add_todo` — Insert a new todo, push rerender down SSE pipe.
async fn action_add_todo(
State(state): State<SharedState>,
Json(body): Json<serde_json::Value>,
@@ -343,51 +291,54 @@ async fn action_add_todo(
.trim()
.to_string();
let signals = SignalStore::from_json(body);
let db = state.db.clone();
action_then_render(
action_then_push(
&state,
body,
signals,
async move {
if !title.is_empty() {
crate::queries::create_todo(&db, &title).await?;
}
Ok(())
},
Some("{newTodo: ''}"), // Clear the input after adding
)
.await
}
/// `POST /action/toggle_todo?id=<i64>` — Toggle a todo's completed status.
/// `POST /action/toggle_todo?id=<i64>` — Toggle completion, push rerender.
async fn action_toggle_todo(
State(state): State<SharedState>,
AxumQuery(params): AxumQuery<ActionIdParams>,
Json(body): Json<serde_json::Value>,
) -> impl IntoResponse {
let signals = SignalStore::from_json(body);
let db = state.db.clone();
let id = params.id;
action_then_render(
action_then_push(
&state,
body,
signals,
async move { crate::queries::toggle_todo(&db, id).await },
None,
)
.await
}
/// `POST /action/delete_todo?id=<i64>` — Delete a todo.
/// `POST /action/delete_todo?id=<i64>` — Delete a todo, push rerender.
async fn action_delete_todo(
State(state): State<SharedState>,
AxumQuery(params): AxumQuery<ActionIdParams>,
Json(body): Json<serde_json::Value>,
) -> impl IntoResponse {
let signals = SignalStore::from_json(body);
let db = state.db.clone();
let id = params.id;
action_then_render(
action_then_push(
&state,
body,
signals,
async move { crate::queries::delete_todo(&db, id).await },
None,
)
.await
}
examples/todo/todo_list.rs
+5 -5
View File
@@ -11,7 +11,7 @@ use maud::{html, Markup};
/// - `cx.run()` for data fetching
/// - `cx.signal()` with `global()` scoping + `Signal::val` in expressions
/// - `cx.signal()` with `mangle().client_only()` scoping (in todo_item)
/// - DataStar `data-bind`, `data-on-click`, `data-attr` attributes
/// - DataStar `data-bind`, `data-on:click`, `data-attr` attributes
/// - `@post()` actions for mutations
pub async fn todo_list(cx: &mut RenderContext) -> anyhow::Result<Markup> {
// Fetch all todos
@@ -34,7 +34,7 @@ pub async fn todo_list(cx: &mut RenderContext) -> anyhow::Result<Markup> {
span.nav-current { "Todos" }
" | "
button.nav-link
data-on-click="$tree = {page: 'About'}; @post('/render')" {
data-on:click="$tree = {page: 'About'};" {
"About"
}
}
@@ -51,7 +51,7 @@ pub async fn todo_list(cx: &mut RenderContext) -> anyhow::Result<Markup> {
data-bind="newTodo"
;
button
data-on-click="@post('/action/add_todo')"
data-on:click="@post('/action/add_todo')"
data-attr=(format!("{{disabled: {}.trim() === ''}}", new_todo.val)) {
"Add"
}
@@ -104,7 +104,7 @@ fn todo_item(cx: &mut RenderContext, todo: &Todo) -> Markup {
input
type="checkbox"
checked[todo.completed]
data-on-click=(format!("@post('/action/toggle_todo?id={}')", todo.id))
data-on:click=(format!("@post('/action/toggle_todo?id={}')", todo.id))
;
// Title with strikethrough when completed (class set server-side)
@@ -114,7 +114,7 @@ fn todo_item(cx: &mut RenderContext, todo: &Todo) -> Markup {
// Delete button
button.delete-btn
data-on-click=(format!("@post('/action/delete_todo?id={}')", todo.id))
data-on:click=(format!("@post('/action/delete_todo?id={}')", todo.id))
{
"×"
}