Serialize the Interactivity API's store from PHP and hydrate it on the client

assets/js/interactivity/constants.js

@@ -1,3 +1,3 @@
-export const cstMetaTagItemprop = 'woo-client-side-transitions';
+export const csnMetaTagItemprop = 'woo-client-side-navigation';
 export const componentPrefix = 'woo-';
 export const directivePrefix = 'data-woo-';

assets/js/interactivity/directives.js

@@ -2,15 +2,15 @@ import { useContext, useMemo, useEffect } from 'preact/hooks';
 import { useSignalEffect } from '@preact/signals';
 import { deepSignal, peek } from 'deepsignal';
 import { directive } from './hooks';
-import { prefetch, navigate, hasClientSideTransitions } from './router';
+import { prefetch, navigate, canDoClientSideNavigation } from './router';
 
 // Until useSignalEffects is fixed:
 // https://github.com/preactjs/signals/issues/228
 const raf = window.requestAnimationFrame;
 const tick = () => new Promise( ( r ) => raf( () => raf( r ) ) );
 
-// Check if current page has client-side transitions enabled.
-const clientSideTransitions = hasClientSideTransitions( document.head );
+// Check if current page can do client-side navigation.
+const clientSideNavigation = canDoClientSideNavigation( document.head );
 
 const isObject = ( item ) =>
 	item && typeof item === 'object' && ! Array.isArray( item );
@@ -91,19 +91,19 @@ export default () => {
 						className: name,
 						context: contextValue,
 					} );
+					const currentClass = element.props.class || '';
+					const classFinder = new RegExp(
+						`(^|\\s)${ name }(\\s|$)`,
+						'g'
+					);
 					if ( ! result )
-						element.props.class = element.props.class
-							.replace(
-								new RegExp( `(^|\\s)${ name }(\\s|$)`, 'g' ),
-								' '
-							)
+						element.props.class = currentClass
+							.replace( classFinder, ' ' )
 							.trim();
-					else if (
-						! new RegExp( `(^|\\s)${ name }(\\s|$)` ).test(
-							element.props.class
-						)
-					)
-						element.props.class += ` ${ name }`;
+					else if ( ! classFinder.test( currentClass ) )
+						element.props.class = currentClass
+							? `${ currentClass } ${ name }`
+							: name;
 
 					useEffect( () => {
 						// This seems necessary because Preact doesn't change the class names
@@ -146,13 +146,13 @@ export default () => {
 		} ) => {
 			useEffect( () => {
 				// Prefetch the page if it is in the directive options.
-				if ( clientSideTransitions && link?.prefetch ) {
+				if ( clientSideNavigation && link?.prefetch ) {
 					prefetch( href );
 				}
 			} );
 
 			// Don't do anything if it's falsy.
-			if ( clientSideTransitions && link !== false ) {
+			if ( clientSideNavigation && link !== false ) {
 				element.props.onclick = async ( event ) => {
 					event.preventDefault();
 

assets/js/interactivity/hooks.js

@@ -1,6 +1,6 @@
 import { h, options, createContext } from 'preact';
 import { useRef } from 'preact/hooks';
-import { store } from './wpx';
+import { rawStore as store } from './store';
 import { componentPrefix } from './constants';
 
 // Main context.
@@ -18,7 +18,7 @@ export const component = ( name, Comp ) => {
 	componentMap[ name ] = Comp;
 };
 
-// Resolve the path to some property of the wpx object.
+// Resolve the path to some property of the store object.
 const resolve = ( path, context ) => {
 	let current = { ...store, context };
 	path.split( '.' ).forEach( ( p ) => ( current = current[ p ] ) );

assets/js/interactivity/index.js

@@ -1,6 +1,7 @@
 import registerDirectives from './directives';
 import registerComponents from './components';
 import { init } from './router';
+export { store } from './store';
 
 /**
  * Initialize the initial vDOM.

assets/js/interactivity/router.js

@@ -1,7 +1,7 @@
 import { hydrate, render } from 'preact';
 import { toVdom, hydratedIslands } from './vdom';
 import { createRootFragment } from './utils';
-import { cstMetaTagItemprop, directivePrefix } from './constants';
+import { csnMetaTagItemprop, directivePrefix } from './constants';
 
 // The root to render the vdom (document.body).
 let rootFragment;
@@ -17,10 +17,10 @@ const cleanUrl = ( url ) => {
 	return u.pathname + u.search;
 };
 
-// Helper to check if a page has client-side transitions activated.
-export const hasClientSideTransitions = ( dom ) =>
+// Helper to check if a page can do client-side navigation.
+export const canDoClientSideNavigation = ( dom ) =>
 	dom
-		.querySelector( `meta[itemprop='${ cstMetaTagItemprop }']` )
+		.querySelector( `meta[itemprop='${ csnMetaTagItemprop }']` )
 		?.getAttribute( 'content' ) === 'active';
 
 // Fetch styles of a new page.
@@ -55,7 +55,7 @@ const fetchHead = async ( head ) => {
 const fetchPage = async ( url ) => {
 	const html = await window.fetch( url ).then( ( r ) => r.text() );
 	const dom = new window.DOMParser().parseFromString( html, 'text/html' );
-	if ( ! hasClientSideTransitions( dom.head ) ) return false;
+	if ( ! canDoClientSideNavigation( dom.head ) ) return false;
 	const head = await fetchHead( dom.head );
 	return { head, body: toVdom( dom.body ) };
 };
@@ -98,7 +98,7 @@ window.addEventListener( 'popstate', async () => {
 
 // Initialize the router with the initial DOM.
 export const init = async () => {
-	if ( hasClientSideTransitions( document.head ) ) {
+	if ( canDoClientSideNavigation( document.head ) ) {
 		// Create the root fragment to hydrate everything.
 		rootFragment = createRootFragment(
 			document.documentElement,

assets/js/interactivity/store.js

@@ -0,0 +1,42 @@
+import { deepSignal } from 'deepsignal';
+
+const isObject = ( item ) =>
+	item && typeof item === 'object' && ! Array.isArray( item );
+
+export const deepMerge = ( target, source ) => {
+	if ( isObject( target ) && isObject( source ) ) {
+		for ( const key in source ) {
+			if ( isObject( source[ key ] ) ) {
+				if ( ! target[ key ] ) Object.assign( target, { [ key ]: {} } );
+				deepMerge( target[ key ], source[ key ] );
+			} else {
+				Object.assign( target, { [ key ]: source[ key ] } );
+			}
+		}
+	}
+};
+
+const getSerializedState = () => {
+	const storeTag = document.querySelector(
+		`script[type="application/json"]#store`
+	);
+	if ( ! storeTag ) return {};
+	try {
+		const { state } = JSON.parse( storeTag.textContent );
+		if ( isObject( state ) ) return state;
+		throw Error( 'Parsed state is not an object' );
+	} catch ( e ) {
+		console.log( e );
+	}
+	return {};
+};
+
+const rawState = getSerializedState();
+export const rawStore = { state: deepSignal( rawState ) };
+
+if ( typeof window !== 'undefined' ) window.store = rawStore;
+
+export const store = ( { state, ...block } ) => {
+	deepMerge( rawStore, block );
+	deepMerge( rawState, state );
+};

phpcs.xml

@@ -66,4 +66,7 @@
 	<rule ref="Generic.Arrays.DisallowShortArraySyntax.Found">
 		<exclude-pattern>src/*</exclude-pattern>
 	</rule>
+
+	<!-- Exclude Interactivity API-->
+	<exclude-pattern>./src/Interactivity/*</exclude-pattern>
 </ruleset>

src/Interactivity/directives/attributes/woo-bind.php

@@ -0,0 +1,22 @@
+<?php
+
+require_once __DIR__ . '/../utils.php';
+
+function process_woo_bind( $tags, $context ) {
+	if ( $tags->is_tag_closer() ) {
+		return;
+	}
+
+	$prefixed_attributes = $tags->get_attribute_names_with_prefix( 'data-woo-bind:' );
+
+	foreach ( $prefixed_attributes as $attr ) {
+		list( , $bound_attr ) = explode( ':', $attr );
+		if ( empty( $bound_attr ) ) {
+			continue;
+		}
+
+		$expr  = $tags->get_attribute( $attr );
+		$value = woo_directives_evaluate( $expr, $context->get_context() );
+		$tags->set_attribute( $bound_attr, $value );
+	}
+}

src/Interactivity/directives/attributes/woo-class.php

@@ -0,0 +1,26 @@
+<?php
+
+require_once __DIR__ . '/../utils.php';
+
+function process_woo_class( $tags, $context ) {
+	if ( $tags->is_tag_closer() ) {
+		return;
+	}
+
+	$prefixed_attributes = $tags->get_attribute_names_with_prefix( 'data-woo-class:' );
+
+	foreach ( $prefixed_attributes as $attr ) {
+		list( , $class_name ) = explode( ':', $attr );
+		if ( empty( $class_name ) ) {
+			continue;
+		}
+
+		$expr      = $tags->get_attribute( $attr );
+		$add_class = woo_directives_evaluate( $expr, $context->get_context() );
+		if ( $add_class ) {
+			$tags->add_class( $class_name );
+		} else {
+			$tags->remove_class( $class_name );
+		}
+	}
+}

src/Interactivity/directives/attributes/woo-context.php

@@ -0,0 +1,18 @@
+<?php
+
+function process_woo_context_attribute( $tags, $context ) {
+	if ( $tags->is_tag_closer() ) {
+		$context->rewind_context();
+		return;
+	}
+
+	$value = $tags->get_attribute( 'data-woo-context' );
+	if ( null === $value ) {
+		// No woo-context directive.
+		return;
+	}
+
+	$new_context = json_decode( $value, true );
+
+	$context->set_context( $new_context );
+}

src/Interactivity/directives/attributes/woo-style.php

@@ -0,0 +1,29 @@
+<?php
+
+require_once __DIR__ . '/../utils.php';
+
+function process_woo_style( $tags, $context ) {
+	if ( $tags->is_tag_closer() ) {
+		return;
+	}
+
+	$prefixed_attributes = $tags->get_attribute_names_with_prefix( 'data-woo-style:' );
+
+	foreach ( $prefixed_attributes as $attr ) {
+		list( , $style_name ) = explode( ':', $attr );
+		if ( empty( $style_name ) ) {
+			continue;
+		}
+
+		$expr        = $tags->get_attribute( $attr );
+		$style_value = woo_directives_evaluate( $expr, $context->get_context() );
+		if ( $style_value ) {
+			$style_attr = $tags->get_attribute( 'style' );
+			$style_attr = woo_directives_set_style( $style_attr, $style_name, $style_value );
+			$tags->set_attribute( 'style', $style_attr );
+		} else {
+			// $tags->remove_class( $style_name );
+		}
+	}
+}
+

src/Interactivity/directives/class-woo-directive-context.php

@@ -0,0 +1,73 @@
+<?php
+/**
+ * Context data implementation.
+ *
+ * @package block-hydration-experiments
+ */
+
+/**
+ * This is a data structure to hold the current context.
+ *
+ * Whenever encountering a `woo-context` directive, we need to update
+ * the context with the data found in that directive. Conversely,
+ * when "leaving" that context (by encountering a closing tag), we
+ * need to reset the context to its previous state. This means that
+ * we actually need sort of a stack to keep track of all nested contexts.
+ *
+ * Example:
+ *
+ * <woo-context data='{ "foo": 123 }'>
+ *     <!-- foo should be 123 here. -->
+ *     <woo-context data='{ "foo": 456 }'>
+ *         <!-- foo should be 456 here. -->
+ *     </woo-context>
+ *     <!-- foo should be reset to 123 here. -->
+ * </woo-context>
+ */
+class Woo_Directive_Context {
+	/**
+	 * The stack used to store contexts internally.
+	 *
+	 * @var array An array of contexts.
+	 */
+	protected $stack = array( array() );
+
+	/**
+	 * Constructor.
+	 *
+	 * Accepts a context as an argument to initialize this with.
+	 *
+	 * @param array $context A context.
+	 */
+	function __construct( $context = array() ) {
+		$this->set_context( $context );
+	}
+
+	/**
+	 * Return the current context.
+	 *
+	 * @return array The current context.
+	 */
+	public function get_context() {
+		return end( $this->stack );
+	}
+
+	/**
+	 * Set the current context.
+	 *
+	 * @param array $context The context to be set.
+	 * @return void
+	 */
+	public function set_context( $context ) {
+		array_push( $this->stack, array_replace_recursive( $this->get_context(), $context ) );
+	}
+
+	/**
+	 * Reset the context to its previous state.
+	 *
+	 * @return void
+	 */
+	public function rewind_context() {
+		array_pop( $this->stack );
+	}
+}