feat: add native code block feature with Prism highlighting and editor integration

- Implemented custom code block system for frontend and editors
- Integrated Prism.js for syntax highlighting (YAML + HTML support)
- Added copy-to-clipboard functionality with hover-based UI
- Introduced custom Gutenberg block for code input
- Added Classic Editor button for quick code insertion
- Implemented server-side rendering via the_content filter
- Added dedicated styling (code.css) with Dracula-inspired theme
- Added editor preview styling (editor.css) for visual consistency
- Ensured accessibility and keyboard support for copy button
- Optimized asset loading and versioning using filemtime()

This feature provides a lightweight, theme-native alternative to external code highlighting plugins.

inc/tools/code-block.php

@@ -0,0 +1,211 @@
+<?php
+/**
+ * Simplified Code Block Feature
+ *
+ * Handles:
+ * - Frontend assets
+ * - Editor assets
+ * - Classic Editor button
+ * - Gutenberg block
+ * - Server-side wrapping for code blocks
+ *
+ * @package Zeitfresser
+ */
+
+if ( ! defined( 'ABSPATH' ) ) {
+	exit;
+}
+
+/**
+ * Get asset version from file modification time.
+ *
+ * @param string $relative_path Relative path inside the theme directory.
+ * @return string
+ */
+function ztfr_code_asset_version( $relative_path ) {
+	$file_path = get_template_directory() . $relative_path;
+
+	if ( file_exists( $file_path ) ) {
+		return (string) filemtime( $file_path );
+	}
+
+	return (string) ZEITFRESSER_VERSION;
+}
+
+/**
+ * Enqueue frontend assets.
+ */
+function ztfr_enqueue_code_assets() {
+
+	if ( is_admin() ) {
+		return;
+	}
+
+	$code_css_version = ztfr_code_asset_version( '/assets/css/code.css' );
+	$prism_version    = ztfr_code_asset_version( '/assets/js/prism.js' );
+	$code_js_version  = ztfr_code_asset_version( '/assets/js/code-block.js' );
+
+	wp_enqueue_style(
+		'ztfr-code',
+		get_template_directory_uri() . '/assets/css/code.css',
+		[],
+		$code_css_version
+	);
+
+	wp_enqueue_script(
+		'ztfr-prism',
+		get_template_directory_uri() . '/assets/js/prism.js',
+		[],
+		$prism_version,
+		true
+	);
+
+	/**
+	 * Disable Prism auto-highlighting.
+	 *
+	 * Prism auto-runs on DOM ready unless Prism.manual is set before the core
+	 * script executes. We disable auto-run so highlighting happens only once
+	 * in our custom script after the DOM is ready.
+	 */
+	wp_add_inline_script(
+		'ztfr-prism',
+		'window.Prism = window.Prism || {}; window.Prism.manual = true;',
+		'before'
+	);
+
+	wp_enqueue_script(
+		'ztfr-code-block',
+		get_template_directory_uri() . '/assets/js/code-block.js',
+		[ 'ztfr-prism' ],
+		$code_js_version,
+		true
+	);
+}
+add_action( 'wp_enqueue_scripts', 'ztfr_enqueue_code_assets' );
+
+/**
+ * Enqueue block editor assets.
+ */
+function ztfr_enqueue_code_block_editor_assets() {
+	$editor_js_version  = ztfr_code_asset_version( '/assets/js/editor.js' );
+	$code_css_version   = ztfr_code_asset_version( '/assets/css/code.css' );
+	$editor_css_version = ztfr_code_asset_version( '/assets/css/editor.css' );
+
+	wp_enqueue_script(
+		'ztfr-code-editor',
+		get_template_directory_uri() . '/assets/js/editor.js',
+		[
+			'wp-blocks',
+			'wp-element',
+			'wp-i18n',
+			'wp-components',
+			'wp-block-editor',
+		],
+		$editor_js_version,
+		true
+	);
+
+	wp_enqueue_style(
+		'ztfr-code-editor-preview',
+		get_template_directory_uri() . '/assets/css/code.css',
+		[],
+		$code_css_version
+	);
+
+	wp_enqueue_style(
+		'ztfr-editor',
+		get_template_directory_uri() . '/assets/css/editor.css',
+		[],
+		$editor_css_version
+	);
+}
+add_action( 'enqueue_block_editor_assets', 'ztfr_enqueue_code_block_editor_assets' );
+
+/**
+ * Register Classic Editor button only for users who can edit and use rich text.
+ */
+function ztfr_register_classic_code_button() {
+
+	if ( ! current_user_can( 'edit_posts' ) && ! current_user_can( 'edit_pages' ) ) {
+		return;
+	}
+
+	if ( 'true' !== get_user_option( 'rich_editing' ) ) {
+		return;
+	}
+
+	add_filter( 'mce_external_plugins', 'ztfr_add_classic_code_plugin' );
+	add_filter( 'mce_buttons', 'ztfr_add_classic_code_button' );
+}
+add_action( 'admin_init', 'ztfr_register_classic_code_button' );
+
+/**
+ * Add TinyMCE plugin script.
+ *
+ * @param array $plugins TinyMCE plugins.
+ * @return array
+ */
+function ztfr_add_classic_code_plugin( $plugins ) {
+	$plugins['ztfr_code_block'] = get_template_directory_uri() . '/assets/js/editor.js';
+	return $plugins;
+}
+
+/**
+ * Add TinyMCE toolbar button.
+ *
+ * @param array $buttons TinyMCE buttons.
+ * @return array
+ */
+function ztfr_add_classic_code_button( $buttons ) {
+	$buttons[] = 'ztfr_code_block';
+	return $buttons;
+}
+
+/**
+ * Wrap code blocks server-side.
+ *
+ * This keeps Classic Editor, Gutenberg and pasted raw code blocks
+ * compatible with the frontend styling without runtime DOM manipulation.
+ *
+ * @param string $content Post content.
+ * @return string
+ */
+function ztfr_wrap_code_blocks( $content ) {
+
+	if ( is_admin() ) {
+		return $content;
+	}
+
+	if ( false === strpos( $content, '<pre' ) ) {
+		return $content;
+	}
+
+	$content = preg_replace_callback(
+		'/<pre([^>]*)><code([^>]*)>(.*?)<\/code><\/pre>/s',
+		function ( $matches ) {
+
+			$pre_attrs  = $matches[1];
+			$code_attrs = $matches[2];
+			$code       = $matches[3];
+
+			if ( false === strpos( $pre_attrs, 'language-' ) ) {
+				$pre_attrs .= ' class="language-yaml"';
+			}
+
+			if ( false === strpos( $code_attrs, 'language-' ) ) {
+				$code_attrs .= ' class="language-yaml"';
+			}
+
+			return sprintf(
+				'<div class="ztfr-code"><pre%s><code%s>%s</code></pre></div>',
+				$pre_attrs,
+				$code_attrs,
+				$code
+			);
+		},
+		$content
+	);
+
+	return $content;
+}
+add_filter( 'the_content', 'ztfr_wrap_code_blocks', 20 );

inc/utilities/helpers.php

@@ -224,3 +224,11 @@ if ( ! function_exists( 'zeitfresser_asset' ) ) {
         return get_template_directory_uri() . '/assets/' . ltrim($path, '/');
     }
 }
+
+/**
+ * Delete Cookie Button
+ */
+ add_filter( 'comment_form_default_fields', function( $fields ) {
+    unset( $fields['cookies'] );
+    return $fields;
+});