Interactivity API: add wp_store

lib/experimental/interactivity-api/class-wp-interactivity-store.php

@@ -0,0 +1,75 @@
+<?php
+/**
+ * WP_Interactivity_Store class
+ *
+ * Manages the initial state of the Interactivity API store in the server and
+ * its serialization so it can be restored in the browser upon hydration.
+ *
+ * @package Gutenberg
+ * @subpackage Interactivity API
+ */
+
+/**
+ * Manages the initial state of the Interactivity API store in the server and
+ * its serialization so it can be restored in the browser upon hydration.
+ *
+ * It's a private class, exposed by other functions, like `wp_store`.
+ *
+ * @access private
+ */
+class WP_Interactivity_Store {
+	/**
+	 * Store.
+	 *
+	 * @var array
+	 */
+	private static $store = array();
+
+	/**
+	 * Get store data.
+	 *
+	 * @return array
+	 */
+	static function get_data() {
+		return self::$store;
+	}
+
+	/**
+	 * Merge data.
+	 *
+	 * @param array $data The data that will be merged with the exsisting store.
+	 */
+	static function merge_data( $data ) {
+		self::$store = array_replace_recursive( self::$store, $data );
+	}
+
+	/**
+	 * Serialize store data to JSON.
+	 *
+	 * @return string|false Serialized JSON data.
+	 */
+	static function serialize() {
+		// TODO: Escape?
+		return wp_json_encode( self::$store );
+	}
+
+	/**
+	 * Reset the store data.
+	 */
+	static function reset() {
+		self::$store = array();
+	}
+
+	/**
+	 * Render the store data.
+	 */
+	static function render() {
+		if ( empty( self::$store ) ) {
+			return;
+		}
+
+		// TODO: decide the final id name.
+		$store = self::serialize();
+		echo "<script id=\"wp-interactivity-store-data\" type=\"application/json\">$store</script>";
+	}
+}

lib/experimental/interactivity-api/scripts.php

@@ -0,0 +1,28 @@
+<?php
+/**
+ * Utils to optimize the interactive scripts.
+ *
+ * @package Gutenberg
+ * @subpackage Interactivity API
+ */
+
+/**
+ * Move interactive scripts to the footer. This is a temporary measure to make
+ * it work with `wp_store` and it should be replaced with deferred scripts or
+ * modules.
+ */
+function gutenberg_interactivity_move_interactive_scripts_to_the_footer() {
+	// Move the @wordpress/interactivity package to the footer.
+	wp_script_add_data( 'wp-interactivity', 'group', 1 );
+
+	// Move all the view scripts of the interactive blocks to the footer.
+	$registered_blocks = \WP_Block_Type_Registry::get_instance()->get_all_registered();
+	foreach ( array_values( $registered_blocks ) as $block ) {
+		if ( isset( $block->supports['interactivity'] ) && $block->supports['interactivity'] ) {
+			foreach ( $block->view_script_handles as $handle ) {
+				wp_script_add_data( $handle, 'group', 1 );
+			}
+		}
+	}
+}
+add_action( 'wp_enqueue_scripts', 'gutenberg_interactivity_move_interactive_scripts_to_the_footer', 11 );

lib/experimental/interactivity-api/store.php

@@ -0,0 +1,26 @@
+<?php
+/**
+ * The functions that expose the store of the WP_Interactivity_Store class.
+ *
+ * @package Gutenberg
+ * @subpackage Interactivity API
+ */
+
+/**
+ * Merge data with the exsisting store.
+ *
+ * @param array $data Data that will be merged with the exsisting store.
+ *
+ * @return $data The current store data.
+ */
+function wp_store( $data = null ) {
+	if ( $data ) {
+		WP_Interactivity_Store::merge_data( $data );
+	}
+	return WP_Interactivity_Store::get_data();
+}
+
+/**
+ * Render the Interactivity API store in the frontend.
+ */
+add_action( 'wp_footer', array( 'WP_Interactivity_Store', 'render' ), 8 );

lib/load.php

@@ -107,6 +107,9 @@ function gutenberg_is_experiment_enabled( $name ) {
 if ( gutenberg_is_experiment_enabled( 'gutenberg-interactivity-api-core-blocks' ) ) {
 	require __DIR__ . '/experimental/interactivity-api/blocks.php';
 }
+require __DIR__ . '/experimental/interactivity-api/class-wp-interactivity-store.php';
+require __DIR__ . '/experimental/interactivity-api/store.php';
+require __DIR__ . '/experimental/interactivity-api/scripts.php';
 
 // Fonts API.
 if ( ! class_exists( 'WP_Fonts' ) ) {

packages/interactivity/src/store.js

@@ -22,7 +22,7 @@ const deepMerge = ( target, source ) => {
 const getSerializedState = () => {
 	// TODO: change the store tag ID for a better one.
 	const storeTag = document.querySelector(
-		`script[type="application/json"]#store`
+		`script[type="application/json"]#wp-interactivity-store-data`
 	);
 	if ( ! storeTag ) return {};
 	try {

phpunit/experimental/interactivity-api/class-wp-interactivity-store-test.php

@@ -0,0 +1,168 @@
+<?php
+/**
+ * `WP_Interactivity_Store` class test.
+ *
+ * @package Gutenberg
+ * @subpackage Interactivity API
+ */
+
+/**
+ * Tests for the `WP_Interactivity_Store` class.
+ *
+ * @group  directives
+ * @covers WP_Interactivity_Store
+ */
+class WP_Interactivity_Store_Test extends WP_UnitTestCase {
+	public function set_up() {
+		// Clear the state before each test.
+		WP_Interactivity_Store::reset();
+	}
+
+	public function test_store_should_be_empty() {
+		$this->assertEmpty( WP_Interactivity_Store::get_data() );
+	}
+
+	public function test_store_can_be_merged() {
+		$data = array(
+			'state' => array(
+				'core' => array(
+					'a'      => 1,
+					'b'      => 2,
+					'nested' => array(
+						'c' => 3,
+					),
+				),
+			),
+		);
+		WP_Interactivity_Store::merge_data( $data );
+		$this->assertSame( $data, WP_Interactivity_Store::get_data() );
+	}
+
+	public function test_store_can_be_extended() {
+		WP_Interactivity_Store::merge_data(
+			array(
+				'state' => array(
+					'core' => array(
+						'a' => 1,
+					),
+				),
+			)
+		);
+		WP_Interactivity_Store::merge_data(
+			array(
+				'state' => array(
+					'core'   => array(
+						'b' => 2,
+					),
+					'custom' => array(
+						'c' => 3,
+					),
+				),
+			)
+		);
+		$this->assertSame(
+			array(
+				'state' => array(
+					'core'   => array(
+						'a' => 1,
+						'b' => 2,
+					),
+					'custom' => array(
+						'c' => 3,
+					),
+				),
+			),
+			WP_Interactivity_Store::get_data()
+		);
+	}
+
+	public function test_store_existing_props_should_be_overwritten() {
+		WP_Interactivity_Store::merge_data(
+			array(
+				'state' => array(
+					'core' => array(
+						'a' => 1,
+					),
+				),
+			)
+		);
+		WP_Interactivity_Store::merge_data(
+			array(
+				'state' => array(
+					'core' => array(
+						'a' => 'overwritten',
+					),
+				),
+			)
+		);
+		$this->assertSame(
+			array(
+				'state' => array(
+					'core' => array(
+						'a' => 'overwritten',
+					),
+				),
+			),
+			WP_Interactivity_Store::get_data()
+		);
+	}
+
+	public function test_store_existing_indexed_arrays_should_be_replaced() {
+		WP_Interactivity_Store::merge_data(
+			array(
+				'state' => array(
+					'core' => array(
+						'a' => array( 1, 2 ),
+					),
+				),
+			)
+		);
+		WP_Interactivity_Store::merge_data(
+			array(
+				'state' => array(
+					'core' => array(
+						'a' => array( 3, 4 ),
+					),
+				),
+			)
+		);
+		$this->assertSame(
+			array(
+				'state' => array(
+					'core' => array(
+						'a' => array( 3, 4 ),
+					),
+				),
+			),
+			WP_Interactivity_Store::get_data()
+		);
+	}
+
+	public function test_store_should_be_correctly_rendered() {
+		WP_Interactivity_Store::merge_data(
+			array(
+				'state' => array(
+					'core' => array(
+						'a' => 1,
+					),
+				),
+			)
+		);
+		WP_Interactivity_Store::merge_data(
+			array(
+				'state' => array(
+					'core' => array(
+						'b' => 2,
+					),
+				),
+			)
+		);
+		ob_start();
+		WP_Interactivity_Store::render();
+		$rendered = ob_get_clean();
+		$this->assertSame(
+			'<script id="wp-interactivity-store-data" type="application/json">{"state":{"core":{"a":1,"b":2}}}</script>',
+			$rendered
+		);
+	}
+}