feat: added state freezing

No re-hydration yet though or saving.

Author: arctic-hen7

examples/basic/.perseus/src/lib.rs

@@ -10,12 +10,12 @@ use perseus::{
         shell::{app_shell, get_initial_state, get_render_cfg, InitialState, ShellProps},
     },
     plugins::PluginAction,
-    state::PageStateStore,
+    state::{AnyFreeze, PageStateStore},
     templates::{RouterState, TemplateNodeType},
     DomNode,
 };
+use std::cell::RefCell;
 use std::rc::Rc;
-use std::{any::Any, cell::RefCell};
 use sycamore::prelude::{cloned, create_effect, view, NodeRef, ReadSignal};
 use sycamore_router::{HistoryIntegration, Router, RouterProps};
 use wasm_bindgen::{prelude::wasm_bindgen, JsValue};
@@ -68,7 +68,7 @@ pub fn run() -> Result<(), JsValue> {
     // Create a page state store to use
     let pss = PageStateStore::default();
     // Create a new global state set to `None`, which will be updated and handled entirely by the template macro from here on
-    let global_state: Rc<RefCell<Box<dyn Any>>> =
+    let global_state: Rc<RefCell<Box<dyn AnyFreeze>>> =
         Rc::new(RefCell::new(Box::new(Option::<()>::None)));
 
     // Create the router we'll use for this app, based on the user's app definition

examples/rx_state/src/index.rs

@@ -1,3 +1,4 @@
+use perseus::state::Freeze;
 use perseus::{Html, RenderFnResultWithCause, Template};
 use sycamore::prelude::*;
 
@@ -16,13 +17,22 @@ pub struct IndexProps {
 #[perseus::template2(IndexPage)]
 pub fn index_page(IndexPropsRx { username }: IndexPropsRx, global_state: AppStateRx) -> View<G> {
     let username_2 = username.clone(); // This is necessary until Sycamore's new reactive primitives are released
+    let frozen_app = Signal::new(String::new()); // This is not part of our data model, so it's not part of the state properties (everything else should be though)
+    let render_ctx = perseus::get_render_ctx!();
+
     view! {
         p { (format!("Greetings, {}!", username.get())) }
         input(bind:value = username_2, placeholder = "Username")
         p { (global_state.test.get()) }
 
         // When the user visits this and then comes back, they'll still be able to see their username (the previous state will be retrieved from the global state automatically)
         a(href = "about") { "About" }
+        br()
+
+        button(on:click = cloned!(frozen_app, render_ctx => move |_| {
+            frozen_app.set(render_ctx.freeze());
+        })) { "Freeze!" }
+        p { (frozen_app.get()) }
     }
 }
 

examples/showcase/src/templates/router_state.rs

@@ -7,8 +7,8 @@ pub fn router_state_page() -> View<G> {
     let load_state = perseus::get_render_ctx!().router.get_load_state();
     let load_state_str = create_memo(
         cloned!(load_state => move || match (*load_state.get()).clone() {
-            RouterLoadState::Loaded(name) => format!("Loaded {}.", name),
-            RouterLoadState::Loading(new) => format!("Loading {}.", new),
+            RouterLoadState::Loaded { template_name, path } => format!("Loaded {} (template: {}).", path, template_name),
+            RouterLoadState::Loading { template_name, path } => format!("Loading {} (template: {}).", path, template_name),
             RouterLoadState::Server => "We're on the server.".to_string()
         }),
     );

packages/perseus-macro/src/rx_state.rs

@@ -196,5 +196,12 @@ pub fn make_rx_impl(mut orig_struct: ItemStruct, name: Ident) -> TokenStream {
                 #make_unrx_fields
             }
         }
+        impl#generics ::perseus::state::Freeze for #name#generics {
+            fn freeze(&self) -> ::std::string::String {
+                let unrx = #make_unrx_fields;
+                // TODO Is this `.unwrap()` safe?
+                ::serde_json::to_string(&unrx).unwrap()
+            }
+        }
     }
 }

packages/perseus-macro/src/template2.rs

@@ -169,15 +169,16 @@ pub fn template_impl(input: TemplateFn, attr_args: AttributeArgs) -> TokenStream
                 // This means that we can pass an `Option<String>` around safely and then deal with it at the template site
                 let global_state_refcell = ::perseus::get_render_ctx!().global_state;
                 let global_state = global_state_refcell.borrow();
-                if (&global_state).downcast_ref::<::std::option::Option::<()>>().is_some() {
+                // This will work if the global state hasn't been initialized yet, because it's the default value that Perseus sets
+                if global_state.as_any().downcast_ref::<::std::option::Option::<()>>().is_some() {
                     // We can downcast it as the type set by the core render system, so we're the first page to be loaded
                     // In that case, we'll set the global state properly
                     drop(global_state);
-                    let mut global_state = global_state_refcell.borrow_mut();
+                    let mut global_state_mut = global_state_refcell.borrow_mut();
                     // This will be defined if we're the first page
                     let global_state_props = &props.global_state.unwrap();
                     let new_global_state = ::serde_json::from_str::<<#global_state_rx as ::perseus::state::MakeUnrx>::Unrx>(global_state_props).unwrap().make_rx();
-                    *global_state = ::std::boxed::Box::new(new_global_state);
+                    *global_state_mut = ::std::boxed::Box::new(new_global_state);
                     // The component function can now access this in `RenderCtx`
                 }
                 // The user's function
@@ -189,7 +190,7 @@ pub fn template_impl(input: TemplateFn, attr_args: AttributeArgs) -> TokenStream
                         let global_state = ::perseus::get_render_ctx!().global_state;
                         let global_state = global_state.borrow();
                         // We can guarantee that it will downcast correctly now, because we'll only invoke the component from this function, which sets up the global state correctly
-                        let global_state_ref = (&global_state).downcast_ref::<#global_state_rx>().unwrap();
+                        let global_state_ref = global_state.as_any().downcast_ref::<#global_state_rx>().unwrap();
                         (*global_state_ref).clone()
                     };
                     #block

packages/perseus/src/lib.rs

@@ -102,7 +102,7 @@ pub mod templates {
 pub mod state {
     pub use crate::global_state::GlobalStateCreator;
     pub use crate::page_state_store::PageStateStore;
-    pub use crate::rx_state::{MakeRx, MakeUnrx};
+    pub use crate::rx_state::*;
 }
 /// A series of exports that should be unnecessary for nearly all uses of Perseus. These are used principally in developing alternative
 /// engines.

packages/perseus/src/page_state_store.rs

@@ -1,14 +1,8 @@
-use std::any::{Any, TypeId};
 use std::cell::RefCell;
 use std::collections::HashMap;
 use std::rc::Rc;
 
-/// A key type for the `PageStateStore` that denotes both a page's state type and its URL.
-#[derive(Hash, PartialEq, Eq)]
-pub struct PageStateKey {
-    state_type: TypeId,
-    url: String,
-}
+use crate::{rx_state::Freeze, state::AnyFreeze};
 
 /// A container for page state in Perseus. This is designed as a context store, in which one of each type can be stored. Therefore, it acts very similarly to Sycamore's context system,
 /// though it's specifically designed for each page to store one reactive properties object. In theory, you could interact with this entirely independently of Perseus' state interface,
@@ -19,47 +13,41 @@ pub struct PageStateKey {
 // TODO Make this work with multiple pages for a single template
 #[derive(Default, Clone)]
 pub struct PageStateStore {
-    /// A map of type IDs to anything, allowing one storage of each type (each type is intended to a properties `struct` for a template). Entries must be `Clone`able becasue we assume them
+    /// A map of type IDs to anything, allowing one storage of each type (each type is intended to a properties `struct` for a template). Entries must be `Clone`able because we assume them
     /// to be `Signal`s or `struct`s composed of `Signal`s.
     // Technically, this should be `Any + Clone`, but that's not possible without something like `dyn_clone`, and we don't need it because we can restrict on the methods instead!
-    map: Rc<RefCell<HashMap<PageStateKey, Box<dyn Any>>>>,
+    map: Rc<RefCell<HashMap<String, Box<dyn AnyFreeze>>>>,
 }
 impl PageStateStore {
-    /// Gets an element out of the state by its type and URL.
-    pub fn get<T: Any + Clone>(&self, url: &str) -> Option<T> {
-        let type_id = TypeId::of::<T>();
-        let key = PageStateKey {
-            state_type: type_id,
-            url: url.to_string(),
-        };
+    /// Gets an element out of the state by its type and URL. If the element stored for the given URL doesn't match the provided type, `None` will be returned.
+    pub fn get<T: AnyFreeze + Clone>(&self, url: &str) -> Option<T> {
         let map = self.map.borrow();
-        map.get(&key).map(|val| {
-            if let Some(val) = val.downcast_ref::<T>() {
-                (*val).clone()
-            } else {
-                // We extracted it by its type ID, it certainly should be able to downcast to that same type ID!
-                unreachable!()
-            }
-        })
+        map.get(url)
+            .map(|val| val.as_any().downcast_ref::<T>().map(|val| (*val).clone()))
+            .flatten()
     }
-    /// Adds a new element to the state by its type and URL. Any existing element with the same type and URL will be silently overriden (use `.contains()` to check first if needed).
-    pub fn add<T: Any + Clone>(&mut self, url: &str, val: T) {
-        let type_id = TypeId::of::<T>();
-        let key = PageStateKey {
-            state_type: type_id,
-            url: url.to_string(),
-        };
+    /// Adds a new element to the state by its URL. Any existing element with the same URL will be silently overriden (use `.contains()` to check first if needed).
+    pub fn add<T: AnyFreeze + Clone>(&mut self, url: &str, val: T) {
         let mut map = self.map.borrow_mut();
-        map.insert(key, Box::new(val));
+        map.insert(url.to_string(), Box::new(val));
+    }
+    /// Checks if the state contains an entry for the given URL.
+    pub fn contains(&self, url: &str) -> bool {
+        self.map.borrow().contains_key(url)
     }
-    /// Checks if the state contains the element of the given type for the given page.
-    pub fn contains<T: Any + Clone>(&self, url: &str) -> bool {
-        let type_id = TypeId::of::<T>();
-        let key = PageStateKey {
-            state_type: type_id,
-            url: url.to_string(),
-        };
-        self.map.borrow().contains_key(&key)
+}
+// Good for convenience, and there's no reason we can't do this
+impl Freeze for PageStateStore {
+    // TODO Avoid literally cloning all the page states here if possible
+    fn freeze(&self) -> String {
+        let map = self.map.borrow();
+        let mut str_map = HashMap::new();
+        for (k, v) in map.iter() {
+            let v_str = v.freeze();
+            str_map.insert(k, v_str);
+        }
+
+        serde_json::to_string(&str_map).unwrap()
     }
 }
 

packages/perseus/src/router.rs

@@ -321,10 +321,20 @@ impl RouterState {
 /// The current load state of the router. You can use this to be warned of when a new page is about to be loaded (and display a loading bar or the like, perhaps).
 #[derive(Clone)]
 pub enum RouterLoadState {
-    /// The page has been loaded. The name of the template is attached.
-    Loaded(String),
+    /// The page has been loaded.
+    Loaded {
+        /// The name of the template being loaded (mostly for convenience).
+        template_name: String,
+        /// The full path to the new page being loaded (including the locale, if we're using i18n).
+        path: String,
+    },
     /// A new page is being loaded, and will soon replace whatever is currently loaded. The name of the new template is attached.
-    Loading(String),
+    Loading {
+        /// The name of the template being loaded (mostly for convenience).
+        template_name: String,
+        /// The full path to the new page being loaded (including the locale, if we're using i18n).
+        path: String,
+    },
     /// We're on the server, and there is no router. Whatever you render based on this state will appear when the user first loads the page, before it's made interactive.
     Server,
 }

packages/perseus/src/rx_state.rs

@@ -1,3 +1,5 @@
+use std::any::Any;
+
 /// A trait for `struct`s that can be made reactive. Typically, this will be derived with the `#[make_rx]` macro, though it can be implemented manually if you have more niche requirements.
 pub trait MakeRx {
     /// The type of the reactive version that we'll convert to. By having this as an associated type, we can associate the reactive type with the unreactive, meaning greater inference
@@ -16,3 +18,29 @@ pub trait MakeUnrx {
     /// and fewer arguments that the user needs to provide to macros.
     fn make_unrx(self) -> Self::Unrx;
 }
+
+/// A trait for reactive `struct`s that can be made unreactive and serialized to a `String`. `struct`s that implement this should implement `MakeUnrx` for simplicity, but they technically don't have
+/// to (they always do in Perseus macro-generated code).
+pub trait Freeze {
+    /// 'Freezes' the reactive `struct` by making it unreactive and converting it to a `String`.
+    fn freeze(&self) -> String;
+}
+
+// Perseus initializes the global state as an `Option::<()>::None`, so it has to implement `Freeze`. It may seem silly, because we wouldn't want to freeze the global state if it hadn't been
+// initialized, but that means it's unmodified from the server, so there would be no point in freezing it (just as there'd be no point in freezing the router state).
+impl Freeze for Option<()> {
+    fn freeze(&self) -> String {
+        serde_json::to_string(&Option::<()>::None).unwrap()
+    }
+}
+
+/// A convenience super-trait for `Freeze`able things that can be downcast to concrete types.
+pub trait AnyFreeze: Freeze + Any {
+    /// Gives `&dyn Any` to enable downcasting.
+    fn as_any(&self) -> &dyn Any;
+}
+impl<T: Any + Freeze> AnyFreeze for T {
+    fn as_any(&self) -> &dyn Any {
+        self
+    }
+}

packages/perseus/src/shell.rs

@@ -3,12 +3,11 @@ use crate::error_pages::ErrorPageData;
 use crate::errors::*;
 use crate::page_data::PageData;
 use crate::path_prefix::get_path_prefix_client;
-use crate::state::PageStateStore;
+use crate::state::{AnyFreeze, PageStateStore};
 use crate::template::Template;
 use crate::templates::{PageProps, RouterLoadState, RouterState, TemplateNodeType};
 use crate::ErrorPages;
 use fmterr::fmt_err;
-use std::any::Any;
 use std::cell::RefCell;
 use std::collections::HashMap;
 use std::rc::Rc;
@@ -255,7 +254,7 @@ pub struct ShellProps {
     /// The container for reactive content.
     pub container_rx_elem: Element,
     /// The global state store. Brekaing it out here prevents it being overriden every time a new template loads.
-    pub global_state: Rc<RefCell<Box<dyn Any>>>,
+    pub global_state: Rc<RefCell<Box<dyn AnyFreeze>>>,
 }
 
 /// Fetches the information for the given page and renders it. This should be provided the actual path of the page to render (not just the
@@ -282,7 +281,10 @@ pub async fn app_shell(
         locale => format!("{}/{}", locale, &path),
     };
     // Update the router state
-    router_state.set_load_state(RouterLoadState::Loading(template.get_path()));
+    router_state.set_load_state(RouterLoadState::Loading {
+        template_name: template.get_path(),
+        path: path_with_locale.clone(),
+    });
     // Get the global state if possible (we'll want this in all cases except errors)
     // If this is a subsequent load, the template macro will have already set up the global state, and it will ignore whatever we naively give it (so we'll give it `None`)
     let global_state = get_global_state();
@@ -345,7 +347,7 @@ pub async fn app_shell(
             let router_state_2 = router_state.clone();
             // BUG (Sycamore): this will double-render if the component is just text (no nodes)
             let page_props = PageProps {
-                path: path_with_locale,
+                path: path_with_locale.clone(),
                 state,
                 global_state,
             };
@@ -384,7 +386,10 @@ pub async fn app_shell(
             );
             checkpoint("page_interactive");
             // Update the router state
-            router_state.set_load_state(RouterLoadState::Loaded(path));
+            router_state.set_load_state(RouterLoadState::Loaded {
+                template_name: path,
+                path: path_with_locale,
+            });
         }
         // If we have no initial state, we should proceed as usual, fetching the content and state from the server
         InitialState::NotPresent => {
@@ -461,10 +466,11 @@ pub async fn app_shell(
                                 let router_state_2 = router_state.clone();
                                 // BUG (Sycamore): this will double-render if the component is just text (no nodes)
                                 let page_props = PageProps {
-                                    path: path_with_locale,
+                                    path: path_with_locale.clone(),
                                     state: page_data.state,
                                     global_state,
                                 };
+                                let template_name = template.get_path();
                                 #[cfg(not(feature = "hydrate"))]
                                 {
                                     // If we aren't hydrating, we'll have to delete everything and re-render
@@ -500,7 +506,10 @@ pub async fn app_shell(
                                 );
                                 checkpoint("page_interactive");
                                 // Update the router state
-                                router_state.set_load_state(RouterLoadState::Loaded(path));
+                                router_state.set_load_state(RouterLoadState::Loaded {
+                                    template_name,
+                                    path: path_with_locale,
+                                });
                             }
                             // If the page failed to serialize, an exception has occurred
                             Err(err) => panic!("page data couldn't be serialized: '{}'", err),