feat: support generating meta boxes

- scaffold directory for custom meta box declarations
- add script to generate meta box configs

Author: dustin-jw

generators/meta-box.js

@@ -0,0 +1,176 @@
+const { writeFileSync } = require('fs');
+const { join } = require('path');
+const prompts = require('prompts');
+
+const getScriptTemplate = ({
+	name,
+	label,
+	abstractClassName,
+	boxIdentifier,
+	postTypes,
+	context,
+	priority,
+}) => `<?php
+/**
+ * File for setting up the ${name} meta box.
+ */
+
+/**
+ * Class that handles all functionality for the ${name} meta box.
+ */
+abstract class ${abstractClassName} {
+	/**
+	 * Set up and add the meta box.
+	 */
+	public static function add() {
+		/**
+		 * Set up basic details about the meta box.
+		 *
+		 * @see https://developer.wordpress.org/reference/functions/add_meta_box/
+		 */
+		add_meta_box(
+			'${boxIdentifier}_id',
+			'${name}',
+			array( self::class, '${boxIdentifier}_html' ),
+			array( ${postTypes.map((postType) => `'${postType}'`).join(', ')} ),
+			'${context}',
+			'${priority}',
+		);
+	}
+
+	/**
+	 * Save the meta box selections.
+	 *
+	 * @param int $post_id  The post ID.
+	 */
+	public static function save( $post_id ) {
+		if ( ! isset( $_POST['${boxIdentifier}_nonce'] ) || ! wp_verify_nonce( sanitize_key( $_POST['${boxIdentifier}_nonce'] ), basename( __FILE__ ) ) ) {
+			return $post_id;
+		}
+
+		$post = get_post( $post_id );
+		$post_type = get_post_type_object( $post->post_type );
+		if ( ! current_user_can( $post_type->cap->edit_post, $post_id ) ) {
+			return $post_id;
+		}
+
+		if ( array_key_exists( '${boxIdentifier}', $_POST ) ) {
+			update_post_meta(
+				$post_id,
+				'_${boxIdentifier}',
+				sanitize_text_field( wp_unslash( $_POST['${boxIdentifier}'] ) )
+			);
+		}
+	}
+
+	/**
+	 * Display the meta box HTML to the user.
+	 *
+	 * @param WP_Post $post   Post object.
+	 */
+	public static function ${boxIdentifier}_html( $post ) {
+		wp_nonce_field( basename( __FILE__ ), '${boxIdentifier}_nonce' );
+		$value = get_post_meta( $post->ID, '_${boxIdentifier}', true );
+		?>
+		<div>
+			<label for="${boxIdentifier}">${label}</label>
+			<div>
+				<input id="${boxIdentifier}" type="text" name="${boxIdentifier}" value="<?php echo esc_attr( $value ); ?>">
+			</div>
+		</div>
+		<?php
+	}
+}
+
+add_action( 'add_meta_boxes', array( '${abstractClassName}', 'add' ) );
+add_action( 'save_post', array( '${abstractClassName}', 'save' ) );
+`;
+
+const getDetails = async () => {
+	const questions = [
+		{
+			type: 'text',
+			name: 'name',
+			message: 'What should the meta box be called?',
+		},
+		{
+			type: 'text',
+			name: 'label',
+			message: 'What should be the label for the field?',
+		},
+		{
+			type: 'list',
+			name: 'postTypes',
+			message:
+				'Which post types should this meta box be enabled for? Enter post type slugs separated by commas (the slugs should match the first argument used in register_post_type).',
+			initial: 'post',
+			separator: ',',
+		},
+		{
+			type: 'select',
+			name: 'context',
+			message: 'In which context should the box be displayed by default? (It can be moved by admins later)',
+			choices: [
+				{
+					title: 'side (in the sidebar)',
+					value: 'side',
+				},
+				{
+					title: 'normal (below the post body)',
+					value: 'normal',
+				},
+				{
+					title: 'advanced (below the post body and "normal" meta boxes)',
+					value: 'advanced',
+				},
+			],
+			initial: 0,
+		},
+		{
+			type: 'select',
+			name: 'priority',
+			message:
+				'What priority level should be used for placing this box by default? (It can be moved by admins later)',
+			choices: [
+				{
+					title: 'high',
+					value: 'high',
+				},
+				{
+					title: 'core',
+					value: 'core',
+				},
+				{
+					title: 'default',
+					value: 'default',
+				},
+				{
+					title: 'low',
+					value: 'low',
+				},
+			],
+			initial: 2,
+		},
+	];
+
+	const response = await prompts(questions);
+
+	return response;
+};
+
+const generatePageTemplate = async () => {
+	const { name, label, postTypes, context, priority } = await getDetails();
+	const abstractClassName = name.replace(/\W/g, '_');
+	const boxIdentifier = name.toLowerCase().replace(/\W/g, '_');
+	const templateDetails = { name, label, abstractClassName, boxIdentifier, postTypes, context, priority };
+
+	const scriptTemplate = getScriptTemplate(templateDetails);
+
+	const fileName = `class-${name.toLowerCase().replace(/\W/g, '-')}`;
+	const scriptPath = join(__dirname, '../src/php/inc/meta-boxes', `${fileName}.php`);
+
+	writeFileSync(scriptPath, scriptTemplate, 'utf-8');
+	console.log(`Created ${scriptPath}`);
+};
+
+generatePageTemplate();

package.json

@@ -44,6 +44,7 @@
     "preimport:uploads": "npm run backup:uploads",
     "generate:custom-block": "node ./generators/custom-block.js",
     "generate:custom-blocks-plugin": "node ./generators/custom-blocks-plugin.js",
+    "generate:meta-box": "node ./generators/meta-box.js",
     "generate:page-template": "node ./generators/page-template.js",
     "generate:pattern": "node ./generators/pattern.js",
     "generate:post-type": "node ./generators/post-type.js",

src/php/functions.php

@@ -60,6 +60,13 @@
 	require_once $filename;
 }
 
+/**
+ * Custom Meta Boxes
+ */
+foreach ( glob( get_template_directory() . '/inc/meta-boxes/*.php' ) as $filename ) {
+	require_once $filename;
+}
+
 /**
  * Enqueue scripts and styles.
  */