Turn the development repository into a WordPress plugin

This will simplify iteration & testing of the updated browser builds

Author: kadamwhite

node-wpapi.php

@@ -0,0 +1,61 @@
+<?php
+/**
+ * Plugin Name: node-wpapi
+ * Plugin URI:  https://github.com/wp-api/node-wpapi
+ * Description: Register the wpapi npm package as a WordPress script.
+ */
+
+namespace WPAPI;
+
+add_action( 'wp enqueue scripts', __NAMESPACE__ . '\\enqueue_scripts' );
+
+/**
+ * Enqueue the wpapi script package.
+ *
+ * @return void
+ */
+function enqueue_scripts() {
+  $uri = plugin_dir_url( __FILE__ ) . 'browser/wpapi.min.js';
+  if ( defined( 'SCRIPT_DEBUG' ) && SCRIPT_DEBUG ) {
+    $uri = plugin_dir_url( __FILE__ ) . 'browser/wpapi.js';
+  }
+
+  // Read the package.json to derive the version number.
+  $package = read_json( plugin_dir_path( __FILE ) . '/package.json' );
+
+  // Enqueue the script itself.
+  wp_enqueue_script(
+    'wpapi',
+    $uri,
+    [],
+    $package['version'] ?? null,
+    true
+  );
+
+  // Inject a JS object into the page to expose the API root URI & nonce.
+  wp_localize_script(
+    'wpapi',
+    'WPAPI_Settings',
+    [
+      'root'  => esc_url_raw( rest_url() ),
+      'nonce' => wp_create_nonce( 'wp_rest' ),
+    ]
+  );
+}
+
+/**
+ * Read & parse a JSON file.
+ *
+ * @param string $path The path to the JSON file to load.
+ * @return array The parsed JSON data object.
+ */
+function read_json( string $path ) : array {
+	if ( ! file_exists( $path ) ) {
+		return [];
+	}
+	$contents = file_get_contents( $path );
+	if ( empty( $contents ) ) {
+		return [];
+	}
+	return json_decode( $contents, true );
+}