Implement PrivateAgent (yewstack#2318)

* Implement PrivateAgent, Separate Threaded into PublicAgent & PrivateAgent.

* Add migration docs.

* Update docs.

examples/agents/src/bin/worker.rs

@@ -1,5 +1,5 @@
 use agents::native_worker::Worker;
-use yew_agent::Threaded;
+use yew_agent::PublicAgent;
 
 fn main() {
     wasm_logger::init(wasm_logger::Config::default());

examples/web_worker_fib/src/lib.rs

@@ -5,7 +5,7 @@ pub mod agent;
 pub mod app;
 use app::Model;
 use wasm_bindgen::prelude::*;
-use yew_agent::Threaded;
+use yew_agent::PublicAgent;
 
 #[wasm_bindgen(start)]
 pub fn start() {

packages/yew-agent/src/lib.rs

@@ -1,4 +1,4 @@
-//! This module contains types to support multi-threading and state management.
+//! This module contains Yew's web worker implementation.
 
 mod hooks;
 mod link;
@@ -10,7 +10,7 @@ pub use link::AgentLink;
 pub(crate) use link::*;
 pub(crate) use pool::*;
 pub use pool::{Dispatched, Dispatcher};
-pub use worker::{Private, Public, Threaded};
+pub use worker::{Private, PrivateAgent, Public, PublicAgent};
 
 use serde::{Deserialize, Serialize};
 use std::fmt;

packages/yew-agent/src/worker/mod.rs

@@ -2,8 +2,8 @@ mod private;
 mod public;
 mod queue;
 
-pub use private::Private;
-pub use public::Public;
+pub use private::{Private, PrivateAgent};
+pub use public::{Public, PublicAgent};
 
 use super::*;
 use js_sys::{Array, Reflect, Uint8Array};
@@ -13,11 +13,19 @@ use web_sys::{
     Blob, BlobPropertyBag, DedicatedWorkerGlobalScope, MessageEvent, Url, Worker, WorkerOptions,
 };
 
-/// Implements rules to register a worker in a separate thread.
-pub trait Threaded {
-    /// Executes an agent in the current environment.
-    /// Uses in `main` function of a worker.
-    fn register();
+pub(crate) struct WorkerResponder {}
+
+impl<AGN> Responder<AGN> for WorkerResponder
+where
+    AGN: Agent,
+    <AGN as Agent>::Input: Serialize + for<'de> Deserialize<'de>,
+    <AGN as Agent>::Output: Serialize + for<'de> Deserialize<'de>,
+{
+    fn respond(&self, id: HandlerId, output: AGN::Output) {
+        let msg = FromWorker::ProcessOutput(id, output);
+        let data = msg.pack();
+        worker_self().post_message_vec(data);
+    }
 }
 
 /// Message packager, based on serde::Serialize/Deserialize

packages/yew-agent/src/worker/private.rs

@@ -21,6 +21,56 @@ pub struct Private<AGN> {
     _agent: PhantomData<AGN>,
 }
 
+/// A trait to enable private agents being registered in a web worker.
+pub trait PrivateAgent {
+    /// Executes an agent in the current environment.
+    /// Uses in `main` function of a worker.
+    fn register();
+}
+
+impl<AGN> PrivateAgent for AGN
+where
+    AGN: Agent<Reach = Private<AGN>>,
+    <AGN as Agent>::Input: Serialize + for<'de> Deserialize<'de>,
+    <AGN as Agent>::Output: Serialize + for<'de> Deserialize<'de>,
+{
+    fn register() {
+        let scope = AgentScope::<AGN>::new();
+        let responder = WorkerResponder {};
+        let link = AgentLink::connect(&scope, responder);
+        let upd = AgentLifecycleEvent::Create(link);
+        scope.send(upd);
+        let handler = move |data: Vec<u8>| {
+            let msg = ToWorker::<AGN::Input>::unpack(&data);
+            match msg {
+                ToWorker::Connected(_id) => {
+                    let upd = AgentLifecycleEvent::Connected(SINGLETON_ID);
+                    scope.send(upd);
+                }
+                ToWorker::ProcessInput(_id, value) => {
+                    let upd = AgentLifecycleEvent::Input(value, SINGLETON_ID);
+                    scope.send(upd);
+                }
+                ToWorker::Disconnected(_id) => {
+                    let upd = AgentLifecycleEvent::Disconnected(SINGLETON_ID);
+                    scope.send(upd);
+                }
+                ToWorker::Destroy => {
+                    let upd = AgentLifecycleEvent::Destroy;
+                    scope.send(upd);
+                    // Terminates web worker
+                    worker_self().close();
+                }
+            }
+        };
+        let loaded: FromWorker<AGN::Output> = FromWorker::WorkerLoaded;
+        let loaded = loaded.pack();
+        let worker = worker_self();
+        worker.set_onmessage_closure(handler);
+        worker.post_message_vec(loaded);
+    }
+}
+
 impl<AGN> Discoverer for Private<AGN>
 where
     AGN: Agent,

packages/yew-agent/src/worker/public.rs

@@ -181,22 +181,14 @@ where
     }
 }
 
-struct WorkerResponder {}
-
-impl<AGN> Responder<AGN> for WorkerResponder
-where
-    AGN: Agent,
-    <AGN as Agent>::Input: Serialize + for<'de> Deserialize<'de>,
-    <AGN as Agent>::Output: Serialize + for<'de> Deserialize<'de>,
-{
-    fn respond(&self, id: HandlerId, output: AGN::Output) {
-        let msg = FromWorker::ProcessOutput(id, output);
-        let data = msg.pack();
-        worker_self().post_message_vec(data);
-    }
+/// A trait to enable public agents being registered in a web worker.
+pub trait PublicAgent {
+    /// Executes an agent in the current environment.
+    /// Uses in `main` function of a worker.
+    fn register();
 }
 
-impl<AGN> Threaded for AGN
+impl<AGN> PublicAgent for AGN
 where
     AGN: Agent<Reach = Public<AGN>>,
     <AGN as Agent>::Input: Serialize + for<'de> Deserialize<'de>,

website/docs/concepts/agents.mdx

@@ -36,8 +36,8 @@ The code can be found in the <desc> tag of the svgs.
   When no bridges are connected to this agent, the agent will disappear.
 
 * Private - Spawn a new agent in a web worker for every new bridge. This is good for moving shared but
-  independent behavior that communicates with the browser out of components. \(TODO verify\) When
-  the task is done, the agent will disappear.
+  independent behavior that communicates with the browser out of components. When
+  the the connected bridge is dropped, the agent will disappear.
 
 * Global \(WIP\)
 

website/docs/migration-guides/yew-agent/from-0_1_0-to-0_2_0.mdx

@@ -2,8 +2,21 @@
 title: "From 0.1.0 to 0.2.0"
 ---
 
+## Removal of `Context` and `Job` Agents
+
 The `Context` and `Job` Agents have been removed in favour of Yew's Context API.
 
 You can see the updated [`pub_sub`](https://github.com/yewstack/yew/tree/master/examples/pub_sub) example about how to use Context API.
 
 For users of `yew_agent::utils::store`, you may switch to third party solutions like: [Yewdux](https://github.com/intendednull/yewdux) or [Bounce](https://github.com/futursolo/bounce).
+
+## `Threaded` is separated into `PublicAgent` and `PrivateAgent`
+
+Replace `use yew_agent::Threaded;` with `use yew_agent::PublicAgent;`.
+
+:::note
+
+`Threaded` was never implemented for Private Agents.
+All existing web worker-based agents are Public Agents.
+
+:::