WordPress/wp-admin/theme-editor.php

<?php
/**
 * Theme file editor administration panel.
 *
 * @package WordPress
 * @subpackage Administration
 */

/** WordPress Administration Bootstrap */
require_once __DIR__ . '/admin.php';

if ( is_multisite() && ! is_network_admin() ) {
	wp_redirect( network_admin_url( 'theme-editor.php' ) );
	exit;
}

if ( ! current_user_can( 'edit_themes' ) ) {
	wp_die( '<p>' . __( 'Sorry, you are not allowed to edit templates for this site.' ) . '</p>' );
}

// Used in the HTML title tag.
$title       = __( 'Edit Themes' );
$parent_file = 'themes.php';

get_current_screen()->add_help_tab(
	array(
		'id'      => 'overview',
		'title'   => __( 'Overview' ),
		'content' =>
				'<p>' . __( 'You can use the theme file editor to edit the individual CSS and PHP files which make up your theme.' ) . '</p>' .
				'<p>' . __( 'Begin by choosing a theme to edit from the dropdown menu and clicking the Select button. A list then appears of the theme&#8217;s template files. Clicking once on any file name causes the file to appear in the large Editor box.' ) . '</p>' .
				'<p>' . __( 'For PHP files, you can use the documentation dropdown to select from functions recognized in that file. Look Up takes you to a web page with reference material about that particular function.' ) . '</p>' .
				'<p id="editor-keyboard-trap-help-1">' . __( 'When using a keyboard to navigate:' ) . '</p>' .
				'<ul>' .
				'<li id="editor-keyboard-trap-help-2">' . __( 'In the editing area, the Tab key enters a tab character.' ) . '</li>' .
				'<li id="editor-keyboard-trap-help-3">' . __( 'To move away from this area, press the Esc key followed by the Tab key.' ) . '</li>' .
				'<li id="editor-keyboard-trap-help-4">' . __( 'Screen reader users: when in forms mode, you may need to press the Esc key twice.' ) . '</li>' .
				'</ul>' .
				'<p>' . __( 'After typing in your edits, click Update File.' ) . '</p>' .
				'<p>' . __( '<strong>Advice:</strong> Think very carefully about your site crashing if you are live-editing the theme currently in use.' ) . '</p>' .
				'<p>' . sprintf(
					/* translators: %s: Link to documentation on child themes. */
					__( 'Upgrading to a newer version of the same theme will override changes made here. To avoid this, consider creating a <a href="%s">child theme</a> instead.' ),
					__( 'https://developer.wordpress.org/themes/advanced-topics/child-themes/' )
				) . '</p>' .
				( is_network_admin() ? '<p>' . __( 'Any edits to files from this screen will be reflected on all sites in the network.' ) . '</p>' : '' ),
	)
);

get_current_screen()->set_help_sidebar(
	'<p><strong>' . __( 'For more information:' ) . '</strong></p>' .
	'<p>' . __( '<a href="https://developer.wordpress.org/themes/">Documentation on Theme Development</a>' ) . '</p>' .
	'<p>' . __( '<a href="https://wordpress.org/documentation/article/appearance-editor-screen/">Documentation on Editing Themes</a>' ) . '</p>' .
	'<p>' . __( '<a href="https://wordpress.org/documentation/article/editing-files/">Documentation on Editing Files</a>' ) . '</p>' .
	'<p>' . __( '<a href="https://developer.wordpress.org/themes/basics/template-tags/">Documentation on Template Tags</a>' ) . '</p>' .
	'<p>' . __( '<a href="https://wordpress.org/support/forums/">Support forums</a>' ) . '</p>'
);

wp_reset_vars( array( 'action', 'error', 'file', 'theme' ) );

if ( $theme ) {
	$stylesheet = $theme;
} else {
	$stylesheet = get_stylesheet();
}

$theme = wp_get_theme( $stylesheet );

if ( ! $theme->exists() ) {
	wp_die( __( 'The requested theme does not exist.' ) );
}

if ( $theme->errors() && 'theme_no_stylesheet' === $theme->errors()->get_error_code() ) {
	wp_die( __( 'The requested theme does not exist.' ) . ' ' . $theme->errors()->get_error_message() );
}

$allowed_files = array();
$style_files   = array();

$file_types = wp_get_theme_file_editable_extensions( $theme );

foreach ( $file_types as $type ) {
	switch ( $type ) {
		case 'php':
			$allowed_files += $theme->get_files( 'php', -1 );
			break;
		case 'css':
			$style_files                = $theme->get_files( 'css', -1 );
			$allowed_files['style.css'] = $style_files['style.css'];
			$allowed_files             += $style_files;
			break;
		default:
			$allowed_files += $theme->get_files( $type, -1 );
			break;
	}
}

// Move functions.php and style.css to the top.
if ( isset( $allowed_files['functions.php'] ) ) {
	$allowed_files = array( 'functions.php' => $allowed_files['functions.php'] ) + $allowed_files;
}
if ( isset( $allowed_files['style.css'] ) ) {
	$allowed_files = array( 'style.css' => $allowed_files['style.css'] ) + $allowed_files;
}

if ( empty( $file ) ) {
	$relative_file = 'style.css';
	$file          = $allowed_files['style.css'];
} else {
	$relative_file = wp_unslash( $file );
	$file          = $theme->get_stylesheet_directory() . '/' . $relative_file;
}

validate_file_to_edit( $file, $allowed_files );

// Handle fallback editing of file when JavaScript is not available.
$edit_error     = null;
$posted_content = null;

if ( 'POST' === $_SERVER['REQUEST_METHOD'] ) {
	$r = wp_edit_theme_plugin_file( wp_unslash( $_POST ) );
	if ( is_wp_error( $r ) ) {
		$edit_error = $r;
		if ( check_ajax_referer( 'edit-theme_' . $stylesheet . '_' . $relative_file, 'nonce', false ) && isset( $_POST['newcontent'] ) ) {
			$posted_content = wp_unslash( $_POST['newcontent'] );
		}
	} else {
		wp_redirect(
			add_query_arg(
				array(
					'a'     => 1, // This means "success" for some reason.
					'theme' => $stylesheet,
					'file'  => $relative_file,
				),
				admin_url( 'theme-editor.php' )
			)
		);
		exit;
	}
}

$settings = array(
	'codeEditor' => wp_enqueue_code_editor( compact( 'file' ) ),
);
wp_enqueue_script( 'wp-theme-plugin-editor' );
wp_add_inline_script( 'wp-theme-plugin-editor', sprintf( 'jQuery( function( $ ) { wp.themePluginEditor.init( $( "#template" ), %s ); } )', wp_json_encode( $settings ) ) );
wp_add_inline_script( 'wp-theme-plugin-editor', 'wp.themePluginEditor.themeOrPlugin = "theme";' );

require_once ABSPATH . 'wp-admin/admin-header.php';

update_recently_edited( $file );

if ( ! is_file( $file ) ) {
	$error = true;
}

$content = '';
if ( ! empty( $posted_content ) ) {
	$content = $posted_content;
} elseif ( ! $error && filesize( $file ) > 0 ) {
	$f       = fopen( $file, 'r' );
	$content = fread( $f, filesize( $file ) );

	if ( '.php' === substr( $file, strrpos( $file, '.' ) ) ) {
		$functions = wp_doc_link_parse( $content );

		if ( ! empty( $functions ) ) {
			$docs_select  = '<select name="docs-list" id="docs-list">';
			$docs_select .= '<option value="">' . esc_html__( 'Function Name&hellip;' ) . '</option>';

			foreach ( $functions as $function ) {
				$docs_select .= '<option value="' . esc_attr( $function ) . '">' . esc_html( $function ) . '()</option>';
			}

			$docs_select .= '</select>';
		}
	}

	$content = esc_textarea( $content );
}

$file_description = get_file_description( $relative_file );
$file_show        = array_search( $file, array_filter( $allowed_files ), true );
$description      = esc_html( $file_description );
if ( $file_description !== $file_show ) {
	$description .= ' <span>(' . esc_html( $file_show ) . ')</span>';
}
?>
<div class="wrap">
<h1><?php echo esc_html( $title ); ?></h1>

<?php if ( isset( $_GET['a'] ) ) : ?>
	<div id="message" class="updated notice is-dismissible">
		<p><?php _e( 'File edited successfully.' ); ?></p>
	</div>
<?php elseif ( is_wp_error( $edit_error ) ) : ?>
	<div id="message" class="notice notice-error">
		<p><?php _e( 'There was an error while trying to update the file. You may need to fix something and try updating again.' ); ?></p>
		<pre><?php echo esc_html( $edit_error->get_error_message() ? $edit_error->get_error_message() : $edit_error->get_error_code() ); ?></pre>
	</div>
<?php endif; ?>

<?php if ( preg_match( '/\.css$/', $file ) && ! wp_is_block_theme() && current_user_can( 'customize' ) ) : ?>
	<div id="message" class="notice-info notice">
		<p><strong><?php _e( 'Did you know?' ); ?></strong></p>
		<p>
			<?php
			printf(
				/* translators: %s: Link to Custom CSS section in the Customizer. */
				__( 'There is no need to change your CSS here &mdash; you can edit and live preview CSS changes in the <a href="%s">built-in CSS editor</a>.' ),
				esc_url( add_query_arg( 'autofocus[section]', 'custom_css', admin_url( 'customize.php' ) ) )
			);
			?>
		</p>
	</div>
<?php endif; ?>

<div class="fileedit-sub">
<div class="alignleft">
<h2>
	<?php
	echo $theme->display( 'Name' );
	if ( $description ) {
		echo ': ' . $description;
	}
	?>
</h2>
</div>
<div class="alignright">
	<form action="theme-editor.php" method="get">
		<label for="theme" id="theme-plugin-editor-selector"><?php _e( 'Select theme to edit:' ); ?> </label>
		<select name="theme" id="theme">
		<?php
		foreach ( wp_get_themes( array( 'errors' => null ) ) as $a_stylesheet => $a_theme ) {
			if ( $a_theme->errors() && 'theme_no_stylesheet' === $a_theme->errors()->get_error_code() ) {
				continue;
			}

			$selected = ( $a_stylesheet === $stylesheet ) ? ' selected="selected"' : '';
			echo "\n\t" . '<option value="' . esc_attr( $a_stylesheet ) . '"' . $selected . '>' . $a_theme->display( 'Name' ) . '</option>';
		}
		?>
		</select>
		<?php submit_button( __( 'Select' ), '', 'Submit', false ); ?>
	</form>
</div>
<br class="clear" />
</div>

<?php
if ( $theme->errors() ) {
	echo '<div class="error"><p><strong>' . __( 'This theme is broken.' ) . '</strong> ' . $theme->errors()->get_error_message() . '</p></div>';
}
?>

<div id="templateside">
	<h2 id="theme-files-label"><?php _e( 'Theme Files' ); ?></h2>
	<ul role="tree" aria-labelledby="theme-files-label">
		<?php if ( $theme->parent() ) : ?>
			<li class="howto">
				<?php
				printf(
					/* translators: %s: Link to edit parent theme. */
					__( 'This child theme inherits templates from a parent theme, %s.' ),
					sprintf(
						'<a href="%s">%s</a>',
						self_admin_url( 'theme-editor.php?theme=' . urlencode( $theme->get_template() ) ),
						$theme->parent()->display( 'Name' )
					)
				);
				?>
			</li>
		<?php endif; ?>
		<li role="treeitem" tabindex="-1" aria-expanded="true" aria-level="1" aria-posinset="1" aria-setsize="1">
			<ul role="group">
				<?php wp_print_theme_file_tree( wp_make_theme_file_tree( $allowed_files ) ); ?>
			</ul>
		</li>
	</ul>
</div>

<?php
if ( $error ) :
	echo '<div class="error"><p>' . __( 'File does not exist! Please double check the name and try again.' ) . '</p></div>';
else :
	?>
	<form name="template" id="template" action="theme-editor.php" method="post">
		<?php wp_nonce_field( 'edit-theme_' . $stylesheet . '_' . $relative_file, 'nonce' ); ?>
		<div>
			<label for="newcontent" id="theme-plugin-editor-label"><?php _e( 'Selected file content:' ); ?></label>
			<textarea cols="70" rows="30" name="newcontent" id="newcontent" aria-describedby="editor-keyboard-trap-help-1 editor-keyboard-trap-help-2 editor-keyboard-trap-help-3 editor-keyboard-trap-help-4"><?php echo $content; ?></textarea>
			<input type="hidden" name="action" value="update" />
			<input type="hidden" name="file" value="<?php echo esc_attr( $relative_file ); ?>" />
			<input type="hidden" name="theme" value="<?php echo esc_attr( $theme->get_stylesheet() ); ?>" />
		</div>

		<?php if ( ! empty( $functions ) ) : ?>
			<div id="documentation" class="hide-if-no-js">
				<label for="docs-list"><?php _e( 'Documentation:' ); ?></label>
				<?php echo $docs_select; ?>
				<input disabled id="docs-lookup" type="button" class="button" value="<?php esc_attr_e( 'Look Up' ); ?>" onclick="if ( '' != jQuery('#docs-list').val() ) { window.open( 'https://api.wordpress.org/core/handbook/1.0/?function=' + escape( jQuery( '#docs-list' ).val() ) + '&amp;locale=<?php echo urlencode( get_user_locale() ); ?>&amp;version=<?php echo urlencode( get_bloginfo( 'version' ) ); ?>&amp;redirect=true'); }" />
			</div>
		<?php endif; ?>

		<div>
			<div class="editor-notices">
				<?php if ( is_child_theme() && $theme->get_stylesheet() === get_template() ) : ?>
					<div class="notice notice-warning inline">
						<p>
							<?php if ( is_writable( $file ) ) : ?>
								<strong><?php _e( 'Caution:' ); ?></strong>
							<?php endif; ?>
							<?php _e( 'This is a file in your current parent theme.' ); ?>
						</p>
					</div>
				<?php endif; ?>
			</div>
			<?php if ( is_writable( $file ) ) : ?>
				<p class="submit">
					<?php submit_button( __( 'Update File' ), 'primary', 'submit', false ); ?>
					<span class="spinner"></span>
				</p>
			<?php else : ?>
				<p>
					<?php
					printf(
						/* translators: %s: Documentation URL. */
						__( 'You need to make this file writable before you can save your changes. See <a href="%s">Changing File Permissions</a> for more information.' ),
						__( 'https://wordpress.org/documentation/article/changing-file-permissions/' )
					);
					?>
				</p>
			<?php endif; ?>
		</div>

		<?php wp_print_file_editor_templates(); ?>
	</form>
	<?php
endif; // End if $error.
?>
<br class="clear" />
</div>
<?php
$dismissed_pointers = explode( ',', (string) get_user_meta( get_current_user_id(), 'dismissed_wp_pointers', true ) );
if ( ! in_array( 'theme_editor_notice', $dismissed_pointers, true ) ) :
	// Get a back URL.
	$referer = wp_get_referer();

	$excluded_referer_basenames = array( 'theme-editor.php', 'wp-login.php' );

	$return_url = admin_url( '/' );
	if ( $referer ) {
		$referer_path = parse_url( $referer, PHP_URL_PATH );
		if ( is_string( $referer_path ) && ! in_array( basename( $referer_path ), $excluded_referer_basenames, true ) ) {
			$return_url = $referer;
		}
	}
	?>
	<div id="file-editor-warning" class="notification-dialog-wrap file-editor-warning hide-if-no-js hidden">
		<div class="notification-dialog-background"></div>
		<div class="notification-dialog">
			<div class="file-editor-warning-content">
				<div class="file-editor-warning-message">
					<h1><?php _e( 'Heads up!' ); ?></h1>
					<p>
						<?php
						_e( 'You appear to be making direct edits to your theme in the WordPress dashboard. It is not recommended! Editing your theme directly could break your site and your changes may be lost in future updates.' );
						?>
					</p>
						<?php
						if ( ! $theme->parent() ) {
							echo '<p>';
							printf(
								/* translators: %s: Link to documentation on child themes. */
								__( 'If you need to tweak more than your theme&#8217;s CSS, you might want to try <a href="%s">making a child theme</a>.' ),
								esc_url( __( 'https://developer.wordpress.org/themes/advanced-topics/child-themes/' ) )
							);
							echo '</p>';
						}
						?>
					<p><?php _e( 'If you decide to go ahead with direct edits anyway, use a file manager to create a copy with a new name and hang on to the original. That way, you can re-enable a functional version if something goes wrong.' ); ?></p>
				</div>
				<p>
					<a class="button file-editor-warning-go-back" href="<?php echo esc_url( $return_url ); ?>"><?php _e( 'Go back' ); ?></a>
					<button type="button" class="file-editor-warning-dismiss button button-primary"><?php _e( 'I understand' ); ?></button>
				</p>
			</div>
		</div>
	</div>
	<?php
endif; // Editor warning notice.

require_once ABSPATH . 'wp-admin/admin-footer.php';