WordPress/wp-admin/theme-editor.php

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

/** WordPress Administration Bootstrap */
require_once( dirname( __FILE__ ) . '/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>' );
}

$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 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>' .
				 /* translators: %s: link to codex article about child themes */
				 '<p>' . sprintf( __( 'Upgrading to a newer version of the same theme will override changes made here.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://codex.wordpress.org/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://codex.wordpress.org/Theme_Development">Documentation on Theme Development</a>' ) . '</p>' .
	'<p>' . __( '<a href="https://codex.wordpress.org/Using_Themes">Documentation on Using Themes</a>' ) . '</p>' .
	'<p>' . __( '<a href="https://codex.wordpress.org/Editing_Files">Documentation on Editing Files</a>' ) . '</p>' .
	'<p>' . __( '<a href="https://codex.wordpress.org/Template_Tags">Documentation on Template Tags</a>' ) . '</p>' .
	'<p>' . __( '<a href="https://wordpress.org/support/">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 = $style_files = array();
$has_templates = false;

$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 );
			$has_templates  = ! empty( $allowed_files );
			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 );

			$docs_select  = '<select name="docs-list" id="docs-list">';
			$docs_select .= '<option value="">' . esc_attr__( 'Function Name&hellip;' ) . '</option>';
			foreach ( $functions as $function ) {
				$docs_select .= '<option value="' . esc_attr( urlencode( $function ) ) . '">' . htmlspecialchars( $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 ) );
	$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 ) ) : ?>
	<div id="message" class="notice-info notice">
		<p><strong><?php _e( 'Did you know?' ); ?></strong></p>
		<p>
			<?php
			echo sprintf(
				/* translators: %s: link to Custom CSS section in the Customizer */
				__( 'There&#8217;s 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">
		<strong><label for="theme"><?php _e( 'Select theme to edit:' ); ?> </label></strong>
		<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 ( ( $has_templates || $theme->parent() ) && $theme->parent() ) : ?>
			<li class="howto">
				<?php
				/* translators: %s: link to edit parent theme */
				echo sprintf(
					__( '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>' . __( 'Oops, no such file exists! Double check the name and try again, merci.' ) . '</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 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_writeable( $file ) ) {
?>
<strong><?php _e( 'Caution:' ); ?></strong><?php } ?>
						<?php _e( 'This is a file in your current parent theme.' ); ?>
					</p>
				</div>
			<?php endif; ?>
		</div>
	<?php if ( is_writeable( $file ) ) : ?>
		<p class="submit">
			<?php submit_button( __( 'Update File' ), 'primary', 'submit', false ); ?>
			<span class="spinner"></span>
		</p>
	<?php else : ?>
		<p><em><?php _e( 'You need to make this file writable before you can save your changes. See <a href="https://codex.wordpress.org/Changing_File_Permissions">the Codex</a> for more information.' ); ?></em></p>
	<?php endif; ?>
	</div>
	<?php wp_print_file_editor_templates(); ?>
	</form>
<?php
endif; // $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' );

	if ( $referer && ! in_array( basename( parse_url( $referer, PHP_URL_PATH ) ), $excluded_referer_basenames, true ) ) {
		$return_url = $referer;
	} else {
		$return_url = admin_url( '/' );
	}
?>
<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
					echo sprintf(
						/* translators: %s: Codex URL */
						__( 'You appear to be making direct edits to your theme in the WordPress dashboard. We recommend that you don&#8217;t! Editing your theme directly could break your site and your changes may be lost in future updates. 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://codex.wordpress.org/Child_Themes' ) )
					);
					?>
				</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

include( ABSPATH . 'wp-admin/admin-footer.php' );