docs: the bridge, browser, and store that's WIP

docs/api/bridge.md

@@ -0,0 +1,115 @@
+---
+title: "@podium/bridge"
+---
+
+This package is a bridge designed to pass [JSON-RPC 2.0](https://www.jsonrpc.org/specification) messages between a web application and a native web view.
+
+## Usage
+
+To install:
+
+```sh
+npm install @podium/bridge
+```
+
+Import the bridge in your client-side bundle:
+
+```js
+import "@podium/bridge";
+```
+
+You should probably send messages via [@podium/browser]. That said, the bridge is available on `window['@podium'].bridge`.
+
+```js
+/** @type {import("@podium/bridge").PodiumBridge} */
+const bridge = window["@podium"].bridge;
+
+// You can listen for incoming messages, which can either be RpcRequest or RpcResponse
+bridge.on("global/authentication", (message) => {
+  const request =
+    /** @type {import("@podium/bridge").RpcRequest<{ token?: string }>} */ (
+      message
+    );
+
+  if (typeof request.token === "string") {
+    // logged in
+  } else {
+    // logged out
+  }
+});
+
+// You can trigger notifications (one-way messages)
+bridge.notification({
+  method: "global/authentication",
+  params: { token: null },
+});
+
+// And you can call methods and await the response
+/** @type {import("@podium/bridge").RpcResponse<{ c: string }>} */
+const response = await bridge.call({
+  method: "document/native-feature",
+  params: { a: "foo", b: "bar" },
+});
+```
+
+## API
+
+### `bridge.on`
+
+Add a listener for incoming messages for a given method name.
+
+```js
+import "@podium/bridge";
+
+/** @type {import("@podium/bridge").PodiumBridge} */
+const bridge = window["@podium"].bridge;
+
+bridge.on("global/authentication", (message) => {
+  const request =
+    /** @type {import("@podium/bridge").RpcRequest<{ token?: string }>} */ (
+      message
+    );
+
+  if (typeof request.token === "string") {
+    // logged in
+  } else {
+    // logged out
+  }
+});
+```
+
+### `bridge.notification`
+
+Send a [notification](https://www.jsonrpc.org/specification#notification) (one-way message).
+
+```js
+import "@podium/bridge";
+
+/** @type {import("@podium/bridge").PodiumBridge} */
+const bridge = window["@podium"].bridge;
+
+bridge.notification({
+  method: "global/authentication",
+  params: { token: null },
+});
+```
+
+### `bridge.call`
+
+Send a [request](https://www.jsonrpc.org/specification#request_object) and await a [response](https://www.jsonrpc.org/specification#response_object).
+
+```js
+import "@podium/bridge";
+
+/** @type {import("@podium/bridge").PodiumBridge} */
+const bridge = window["@podium"].bridge;
+
+/** @type {import("@podium/bridge").RpcResponse<{ c: string }>} */
+const response = await bridge.call({
+  method: "document/native-feature",
+  params: { a: "foo", b: "bar" },
+});
+```
+
+[@podium/browser]: /docs/api/browser
+[@podium/store]: /docs/api/store

docs/api/browser.md

@@ -4,6 +4,9 @@ title: "@podium/browser"
 ---
 
 The `@podium/browser` module is a client-side library designed to simplify communication between a podlet and the layout, and between podlets.
+The module also supports applications running in a [hybrid application](/docs/guides/hybrid#client-side-communcication) when used with [@podium/bridge](/docs/api/bridge).
+
+For an API designed as reactive state, see [@podium/store](/docs/api/store).
 
 ## Installation
 
@@ -55,11 +58,11 @@ Publish an event for a channel and topic combination. Returns the event object p
 
 This method takes the following arguments:
 
-| option  | default | type     | required | details                   |
-| ------- | ------- | -------- | -------- | ------------------------- |
-| channel | `null`  | `string` | `true`   | Name of the channel       |
-| topic   | `null`  | `string` | `true`   | Name of the topic         |
-| payload | `null`  | any      | `false`  | The payload for the event |
+| option  | default | type     | required | details                                                                         |
+| ------- | ------- | -------- | -------- | ------------------------------------------------------------------------------- |
+| channel | `null`  | `string` | `true`   | Name of the channel. Podium reserves `system` and `view` for built-in features. |
+| topic   | `null`  | `string` | `true`   | Name of the topic.                                                              |
+| payload | `null`  | any      | `false`  | The payload for the event.                                                      |
 
 Examples:
 
@@ -77,7 +80,7 @@ This method takes the following arguments:
 
 | option   | default | type       | required | details                                                   |
 | -------- | ------- | ---------- | -------- | --------------------------------------------------------- |
-| channel  | `null`  | `string`   | `true`   | Name of the channel                                       |
+| channel  | `null`  | `string`   | `true`   | Name of the channel.                                      |
 | topic    | `null`  | `string`   | `true`   | Name of the topic                                         |
 | callback | `null`  | `Function` | `true`   | Callback function to be invoked. Receives an event object |
 

docs/api/store.md

@@ -0,0 +1,158 @@
+---
+title: "@podium/store"
+---
+
+This is a client-side library that provides a reactive data store using [nanostores](https://github.com/stores/stores) on top of [@podium/browser](https://github.com/podium-lib/browser)'s `MessageBus`. It includes some ready-made stores and helpers for you to make reactive stores for your own events.
+
+By using reactive state backed by `MessageBus` you can seamlessly share state between different parts of a Podium application. If a podlet changes the value of shared state, all other podlets using that value can update.
+
+<!-- TODO: look into an existing nanostores plugin so we make something that fits the ecosystem -->
+
+## Usage
+
+To install:
+
+```sh
+npm install @podium/store
+```
+
+Use an [included store](#included-stores) in your client-side application:
+
+```js
+// store/user.js
+import { $authentication } from "@podium/store";
+import { computed } from "nanostores";
+
+// You can optionally make a computed value based on the included store
+export const $loggedIn = computed($authentication, (authentication) =>
+  Boolean(authentication.token)
+);
+
+// Colocating actions with the store makes it easier to
+// see what can trigger updates.
+export function logIn(token) {
+  $authentication.set({ token });
+}
+
+export function logOut() {
+  $authentication.set({ token: null });
+}
+```
+
+Use the reactive store to do minimal updates of your UI when state changes. Nanostores supports multiple view frameworks:
+
+- [React and Preact](https://github.com/stores/stores?tab=readme-ov-file#react--preact)
+- [Lit](https://github.com/stores/stores?tab=readme-ov-file#lit)
+- [Vue](https://github.com/stores/stores?tab=readme-ov-file#vue)
+- [Vanilla JS](https://github.com/stores/stores?tab=readme-ov-file#vanilla-js)
+
+This example shows a React component:
+
+```js
+// components/user.jsx
+import { useStore } from "@nanostores/react";
+import { $loggedIn } from "../stores/user.js";
+
+export const User = () => {
+  const loggedIn = useStore($loggedIn);
+  return <p>{loggedIn ? "Welcome!" : "Please log in"}</p>;
+};
+```
+
+This is the same component in Lit:
+
+```js
+// components/user.js
+import { StoreController } from "@nanostores/lit";
+import { $loggedIn } from "../stores/user.js";
+
+class User extends LitElement {
+  loggedInController = new StoreController(this, $loggedIn);
+
+  render() {
+    return html`<p>
+      ${this.loggedInController.value ? "Welcome!" : "Please log in"}
+    </p>`;
+  }
+}
+
+customElements.define("a-user", User);
+```
+
+### Create your own reactive state
+
+By using the [included helper](#mapchannel-topic-initialvalue) you can make your reactive state sync between the different parts of a Podium application.
+
+## API
+
+### `$authentication`
+
+Type: [`map`](https://github.com/stores/stores?tab=readme-ov-file#maps)
+
+```js
+import { $authentication } from "@podium/store";
+```
+
+### `atom(channel, topic, initialValue)`
+
+Create your own [`atom`](https://github.com/nanostores/nanostores?tab=readme-ov-file#atoms) that syncs between parts of a Podium application using the [MessageBus](https://github.com/podium-lib/browser).
+
+This method requires the following arguments:
+
+| option  | type     | details                                                                                                                                              |
+| ------- | -------- | ---------------------------------------------------------------------------------------------------------------------------------------------------- |
+| channel | `string` | Name of the channel                                                                                                                                  |
+| topic   | `string` | Name of the topic                                                                                                                                    |
+| payload | `object` | The initial value. Replaced if [`peek(channel, topic)`](https://github.com/podium-lib/browser?tab=readme-ov-file#peekchannel-topic) returns a value. |
+
+```js
+import { atom } from "@podium/store";
+
+const $reminders = atom("reminders", "list", []);
+```
+
+### `map(channel, topic, initialValue)`
+
+Create your own [`map`](https://github.com/nanostores/nanostores?tab=readme-ov-file#maps) that syncs between parts of a Podium application using the [MessageBus](https://github.com/podium-lib/browser).
+
+This method requires the following arguments:
+
+| option  | type     | details                                                                                                                                              |
+| ------- | -------- | ---------------------------------------------------------------------------------------------------------------------------------------------------- |
+| channel | `string` | Name of the channel                                                                                                                                  |
+| topic   | `string` | Name of the topic                                                                                                                                    |
+| payload | `object` | The initial value. Replaced if [`peek(channel, topic)`](https://github.com/podium-lib/browser?tab=readme-ov-file#peekchannel-topic) returns a value. |
+
+```js
+import { map } from "@podium/store";
+
+const $user = map("user", "profile", { displayName: "foobar" });
+```
+
+### `deepMap(channel, topic, initialValue)`
+
+Create your own [`deepMap`](https://github.com/nanostores/nanostores?tab=readme-ov-file#deep-maps) that syncs between parts of a Podium application using the [MessageBus](https://github.com/podium-lib/browser).
+
+This method requires the following arguments:
+
+| option  | type     | details                                                                                                                                              |
+| ------- | -------- | ---------------------------------------------------------------------------------------------------------------------------------------------------- |
+| channel | `string` | Name of the channel                                                                                                                                  |
+| topic   | `string` | Name of the topic                                                                                                                                    |
+| payload | `object` | The initial value. Replaced if [`peek(channel, topic)`](https://github.com/podium-lib/browser?tab=readme-ov-file#peekchannel-topic) returns a value. |
+
+```js
+import { deepMap, listenKeys } from "@podium/store";
+
+export const $profile = deepMap({
+  hobbies: [
+    {
+      name: "woodworking",
+      friends: [{ id: 123, name: "Ron Swanson" }],
+    },
+  ],
+  skills: [["Carpentry", "Sanding"], ["Varnishing"]],
+});
+
+listenKeys($profile, ["hobbies[0].friends[0].name", "skills[0][0]"]);
+```

docs/guides/assets.md

@@ -124,3 +124,12 @@ Using the [shadow DOM](https://developer.mozilla.org/en-US/docs/Web/API/Web_comp
 With `podlet.css()` the end result is a `<link />` tag in the HTML document's `<head />`. If your podlet's content renders inside a shadow DOM that CSS won't be able to reach the podlet.
 
 With a declarative shadow DOM you have to include your own `<link />` to the CSS from inside the shadow DOM.
+
+### Islands architecture
+
+Podium works well with [islands architecture](https://jasonformat.com/islands-architecture/) where interactivity on the client is handled by small, isolated applications.
+
+Especially when building your layout:
+
+- Consider how JavaScript libraries you use handle external content (external in the sense that it is not generated by your library).
+- Be mindful of how much of the document your JavaScript library hydrates.