feat: improved global state system (#223)

* feat: made global state accessible through function

This removes the function parameter method of accessing it.

* refactor: made global state functions private on `RenderCtx`

The macros don't handle global state now, and the user should just need `.get_global_state()`/`.try_get_global_state()`.

* refactor: removed global state glob imports

These used to be necessary to ensure that the macros could access the
intermediate types, but the new functional access system prevents this!

* chore: removed old commented code from tempalte macro

* feat: removed need for importing intermediate reactive types

These are now accessed purely through trait linkage, meaning no more
weird glob imports for apps that stored their reactive state in
different modules (or apps that were accessing state from another page
outside that page).

* fix: fixed `BorrowMut` errors on global state thawing

* refactor: privatized global state on `RenderCtx`

This prevents `BorrowMut` panics that are fairly likely if users access
the global state manually. If this affects anyone's apps, please let me know!

* chore: removed `get_render_ctx!()` macro

This is pointless with `RenderCtx::from_ctx`. Also added `RenderCtx` to
`perseus::prelude` for convenience.

* chore: cleaned up a few things

BREAKING CHANGES: removed `get_render_ctx!(cx)` in favor of `RenderCtx::from_ctx(cx)`; privatized global state on `RenderCtx`; made global state accessible through `render_ctx.get_global_state::<T>(cx)`, rather than through template function parameter

Author: arctic-hen7

examples/core/freezing_and_thawing/src/templates/about.rs

@@ -1,15 +1,17 @@
+use perseus::prelude::*;
 use perseus::state::Freeze;
-use perseus::{Html, Template};
 use sycamore::prelude::*;
 
-use crate::global_state::*;
+use crate::global_state::AppStateRx;
 
 #[perseus::template_rx]
-pub fn about_page<'a, G: Html>(cx: Scope<'a>, _: (), global_state: AppStateRx<'a>) -> View<G> {
+pub fn about_page<'a, G: Html>(cx: Scope<'a>) -> View<G> {
     // This is not part of our data model, we do NOT want the frozen app
     // synchronized as part of our page's state, it should be separate
     let frozen_app = create_signal(cx, String::new());
-    let render_ctx = perseus::get_render_ctx!(cx);
+    let render_ctx = RenderCtx::from_ctx(cx);
+
+    let global_state = render_ctx.get_global_state::<AppStateRx>(cx);
 
     view! { cx,
         p(id = "global_state") { (global_state.test.get()) }

examples/core/freezing_and_thawing/src/templates/index.rs

@@ -1,24 +1,22 @@
+use perseus::prelude::*;
 use perseus::state::Freeze;
-use perseus::{Html, RenderFnResultWithCause, Template};
 use sycamore::prelude::*;
 
-use crate::global_state::*;
+use crate::global_state::AppStateRx;
 
 #[perseus::make_rx(IndexPropsRx)]
 pub struct IndexProps {
     username: String,
 }
 
 #[perseus::template_rx]
-pub fn index_page<'a, G: Html>(
-    cx: Scope<'a>,
-    state: IndexPropsRx<'a>,
-    global_state: AppStateRx<'a>,
-) -> View<G> {
+pub fn index_page<'a, G: Html>(cx: Scope<'a>, state: IndexPropsRx<'a>) -> View<G> {
     // This is not part of our data model, we do NOT want the frozen app
     // synchronized as part of our page's state, it should be separate
     let frozen_app = create_signal(cx, String::new());
-    let render_ctx = perseus::get_render_ctx!(cx);
+    let render_ctx = RenderCtx::from_ctx(cx);
+
+    let global_state = render_ctx.get_global_state::<AppStateRx>(cx);
 
     view! { cx,
         // For demonstration, we'll let the user modify the page's state and the global state arbitrarily

examples/core/global_state/src/templates/about.rs

@@ -1,12 +1,12 @@
-use perseus::{Html, Template};
-use sycamore::prelude::{view, Scope, SsrNode, View};
+use perseus::prelude::*;
+use sycamore::prelude::*;
 
-use crate::global_state::*; // See the index page for why we need this
+use crate::global_state::AppStateRx;
 
-// This template needs global state, but doesn't have any state of its own, so
-// the first argument is the unit type `()` (which the macro will detect)
 #[perseus::template_rx]
-pub fn about_page<'a, G: Html>(cx: Scope<'a>, _: (), global_state: AppStateRx<'a>) -> View<G> {
+pub fn about_page<'a, G: Html>(cx: Scope<'a>) -> View<G> {
+    let global_state = RenderCtx::from_ctx(cx).get_global_state::<AppStateRx>(cx);
+
     view! { cx,
         // The user can change the global state through an input, and the changes they make will be reflected throughout the app
         p { (global_state.test.get()) }

examples/core/global_state/src/templates/index.rs

@@ -1,13 +1,16 @@
-use perseus::{Html, Template};
-use sycamore::prelude::{view, Scope, SsrNode, View};
+use perseus::prelude::*;
+use sycamore::prelude::*;
 
-use crate::global_state::*; // This is necessary because Perseus generates an invisible intermediary
-                            // `struct` that the template needs access to
+use crate::global_state::AppStateRx;
 
-// This template needs global state, but doesn't have any state of its own, so
-// the first argument is the unit type `()` (which the macro will detect)
+// Note that this template takes no state of its own in this example, but it
+// certainly could
 #[perseus::template_rx]
-pub fn index_page<'a, G: Html>(cx: Scope<'a>, _: (), global_state: AppStateRx<'a>) -> View<G> {
+pub fn index_page<'a, G: Html>(cx: Scope<'a>) -> View<G> {
+    // We access the global state through the render context, extracted from
+    // Sycamore's context system
+    let global_state = RenderCtx::from_ctx(cx).get_global_state::<AppStateRx>(cx);
+
     view! { cx,
         // The user can change the global state through an input, and the changes they make will be reflected throughout the app
         p { (global_state.test.get()) }

examples/core/idb_freezing/src/templates/about.rs

@@ -1,17 +1,17 @@
-use perseus::{Html, Template};
+use perseus::prelude::*;
 use sycamore::prelude::*;
 
-use crate::global_state::*;
+use crate::global_state::AppStateRx;
 
 #[perseus::template_rx]
-pub fn about_page<'a, G: Html>(cx: Scope<'a>, _: (), global_state: AppStateRx<'a>) -> View<G> {
+pub fn about_page<'a, G: Html>(cx: Scope<'a>) -> View<G> {
     // This is not part of our data model
     let freeze_status = create_signal(cx, String::new());
     // It's faster to get this only once and rely on reactivity
     // But it's unused when this runs on the server-side because of the target-gate
     // below
-    #[allow(unused_variables)]
-    let render_ctx = perseus::get_render_ctx!(cx);
+    let render_ctx = RenderCtx::from_ctx(cx);
+    let global_state = render_ctx.get_global_state::<AppStateRx>(cx);
 
     view! { cx,
         p(id = "global_state") { (global_state.test.get()) }

examples/core/idb_freezing/src/templates/index.rs

@@ -1,27 +1,23 @@
-use perseus::{Html, RenderFnResultWithCause, Template};
+use perseus::prelude::*;
 use sycamore::prelude::*;
 
-use crate::global_state::*;
+use crate::global_state::AppStateRx;
 
 #[perseus::make_rx(IndexPropsRx)]
 pub struct IndexProps {
     username: String,
 }
 
 #[perseus::template_rx]
-pub fn index_page<'a, G: Html>(
-    cx: Scope<'a>,
-    state: IndexPropsRx<'a>,
-    global_state: AppStateRx<'a>,
-) -> View<G> {
+pub fn index_page<'a, G: Html>(cx: Scope<'a>, state: IndexPropsRx<'a>) -> View<G> {
     // This is not part of our data model
     let freeze_status = create_signal(cx, String::new());
     let thaw_status = create_signal(cx, String::new());
     // It's faster to get this only once and rely on reactivity
     // But it's unused when this runs on the server-side because of the target-gate
     // below
-    #[allow(unused_variables)]
-    let render_ctx = perseus::get_render_ctx!(cx);
+    let render_ctx = RenderCtx::from_ctx(cx);
+    let global_state = render_ctx.get_global_state::<AppStateRx>(cx);
 
     view! { cx,
         // For demonstration, we'll let the user modify the page's state and the global state arbitrarily

examples/core/router_state/src/templates/index.rs

@@ -1,9 +1,10 @@
-use perseus::{router::RouterLoadState, Html, Template};
-use sycamore::prelude::{create_memo, view, Scope, View};
+use perseus::prelude::*;
+use perseus::router::RouterLoadState;
+use sycamore::prelude::*;
 
 #[perseus::template_rx]
 pub fn router_state_page<G: Html>(cx: Scope) -> View<G> {
-    let load_state = perseus::get_render_ctx!(cx).router.get_load_state(cx);
+    let load_state = RenderCtx::from_ctx(cx).router.get_load_state(cx);
     // This uses Sycamore's `create_memo` to create a state that will update
     // whenever the router state changes
     let load_state_str = create_memo(cx, || match (*load_state.get()).clone() {

examples/demos/auth/src/templates/index.rs

@@ -1,9 +1,11 @@
 use crate::global_state::*;
-use perseus::{Html, Template};
+use perseus::prelude::*;
 use sycamore::prelude::*;
 
 #[perseus::template_rx]
-fn index_view<'a, G: Html>(cx: Scope<'a>, _: (), AppStateRx { auth }: AppStateRx<'a>) -> View<G> {
+fn index_view<'a, G: Html>(cx: Scope<'a>) -> View<G> {
+    let AppStateRx { auth } = RenderCtx::from_ctx(cx).get_global_state::<AppStateRx>(cx);
+
     let AuthDataRx { state, username } = auth;
     // This isn't part of our data model because it's only used here to pass to the
     // login function

packages/perseus-macro/src/rx_state.rs

@@ -11,6 +11,9 @@ pub fn make_rx_impl(mut orig_struct: ItemStruct, name_raw: Ident) -> TokenStream
     // fields, we'll just copy the struct and change the parts we want to
     // We won't create the final `struct` yet to avoid more operations than
     // necessary
+    // Note that we leave this as whatever visibility the original state was to
+    // avoid compiler errors (since it will be exposed as a trait-linked type
+    // through the ref struct)
     let mut mid_struct = orig_struct.clone(); // This will use `RcSignal`s, and will be stored in context
     let ItemStruct {
         ident: orig_name,
@@ -301,12 +304,17 @@ pub fn make_rx_impl(mut orig_struct: ItemStruct, name_raw: Ident) -> TokenStream
                 ::serde_json::to_string(&unrx).unwrap()
             }
         }
-        #[derive(::std::clone::Clone)]
-        #ref_struct
-        impl #generics #mid_name #generics {
-            pub fn to_ref_struct(self, cx: ::sycamore::prelude::Scope) -> #ref_name #generics {
+        // TODO Generics
+        impl ::perseus::state::MakeRxRef for #mid_name {
+            type RxRef<'a> = #ref_name<'a>;
+            fn to_ref_struct<'a>(self, cx: ::sycamore::prelude::Scope<'a>) -> #ref_name<'a> {
                 #make_ref_fields
             }
         }
+        #[derive(::std::clone::Clone)]
+        #ref_struct
+        impl<'a> ::perseus::state::RxRef for #ref_name<'a> {
+            type RxNonRef = #mid_name;
+        }
     }
 }