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: placeholder is 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 sprintf( __( 'Upgrading to a newer version of the same theme will override changes made here.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;
$default_types = array(
	'bash',
	'conf',
	'css',
	'diff',
	'htm',
	'html',
	'http',
	'inc',
	'include',
	'js',
	'json',
	'jsx',
	'less',
	'md',
	'patch',
	'php',
	'php3',
	'php4',
	'php5',
	'php7',
	'phps',
	'phtml',
	'sass',
	'scss',
	'sh',
	'sql',
	'svg',
	'text',
	'txt',
	'xml',
	'yaml',
	'yml',
);

/**
 * Filters the list of file types allowed for editing in the Theme editor.
 *
 * @since 4.4.0
 *
 * @param array    $default_types List of file types. Default types include 'php' and 'css'.
 * @param WP_Theme $theme         The current Theme object.
 */
$file_types = apply_filters( 'wp_theme_editor_filetypes', $default_types, $theme );

// Ensure that default types are still there.
$file_types = array_unique( array_merge( $file_types, $default_types ) );

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' );
			$allowed_files['style.css'] = $style_files['style.css'];
			$allowed_files += $style_files;
			break;
		default:
			$allowed_files += $theme->get_files( $type );
			break;
	}
}

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 );
$scrollto = isset( $_REQUEST['scrollto'] ) ? (int) $_REQUEST['scrollto'] : 0;

switch( $action ) {
case 'update':
	check_admin_referer( 'edit-theme_' . $file . $stylesheet );
	$newcontent = wp_unslash( $_POST['newcontent'] );
	$location = 'theme-editor.php?file=' . urlencode( $relative_file ) . '&theme=' . urlencode( $stylesheet ) . '&scrollto=' . $scrollto;
	if ( is_writeable( $file ) ) {
		// is_writable() not always reliable, check return value. see comments @ https://secure.php.net/is_writable
		$f = fopen( $file, 'w+' );
		if ( $f !== false ) {
			fwrite( $f, $newcontent );
			fclose( $f );
			$location .= '&updated=true';
			$theme->cache_delete();
		}
	}
	wp_redirect( $location );
	exit;

default:

	$settings = wp_enqueue_code_editor( compact( 'file' ) );
	if ( ! empty( $settings ) ) {
		wp_enqueue_script( 'wp-theme-plugin-editor' );
		wp_add_inline_script( 'wp-theme-plugin-editor', sprintf( 'jQuery( function() { wp.themePluginEditor.init( %s ); } )', wp_json_encode( $settings ) ) );
	}

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

	update_recently_edited( $file );

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

	$content = '';
	if ( ! $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 );
	}

	if ( isset( $_GET['updated'] ) ) : ?>
 <div id="message" class="updated notice is-dismissible"><p><?php _e( 'File edited successfully.' ) ?></p></div>
<?php endif;

$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>

<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="post">
		<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">
<?php
if ( $allowed_files ) :
	$previous_file_type = '';

	foreach ( $allowed_files as $filename => $absolute_filename ) :
		$file_type = substr( $filename, strrpos( $filename, '.' ) );

		if ( $file_type !== $previous_file_type ) {
			if ( '' !== $previous_file_type ) {
				echo "\t</ul>\n";
			}

			switch ( $file_type ) {
				case '.php':
					if ( $has_templates || $theme->parent() ) :
						echo "\t<h2>" . __( 'Templates' ) . "</h2>\n";
						if ( $theme->parent() ) {
							echo '<p class="howto">' . 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' )
								)
							) . "</p>\n";
						}
					endif;
					break;
				case '.css':
					echo "\t<h2>" . _x( 'Styles', 'Theme stylesheets in theme editor' ) . "</h2>\n";
					break;
				default:
					/* translators: %s: file extension */
					echo "\t<h2>" . sprintf( __( '%s files' ), $file_type ) . "</h2>\n";
					break;
			}

			echo "\t<ul>\n";
		}

		$file_description = esc_html( get_file_description( $filename ) );
		if ( $filename !== basename( $absolute_filename ) || $file_description !== $filename ) {
			$file_description .= '<br /><span class="nonessential">(' . esc_html( $filename ) . ')</span>';
		}

		if ( $absolute_filename === $file ) {
			$file_description = '<span class="notice notice-info">' . $file_description . '</span>';
		}

		$previous_file_type = $file_type;
?>
		<li><a href="theme-editor.php?file=<?php echo urlencode( $filename ) ?>&amp;theme=<?php echo urlencode( $stylesheet ) ?>"><?php echo $file_description; ?></a></li>
<?php
	endforeach;
?>
</ul>
<?php endif; ?>
</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_' . $file . $stylesheet ); ?>
		<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() ); ?>" />
			<input type="hidden" name="scrollto" id="scrollto" value="<?php echo esc_attr( $scrollto ); ?>" />
		</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>
		<?php if ( is_child_theme() && $theme->get_stylesheet() == get_template() ) : ?>
			<p><?php if ( is_writeable( $file ) ) { ?><strong><?php _e( 'Caution:' ); ?></strong><?php } ?>
			<?php _e( 'This is a file in your current parent theme.' ); ?></p>
		<?php endif; ?>
<?php
	if ( is_writeable( $file ) ) :
		submit_button( __( 'Update File' ), 'primary', 'submit', true );
	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>
	</form>
<?php
endif; // $error
?>
<br class="clear" />
</div>
<script type="text/javascript">
jQuery(document).ready(function($){
	$('#template').submit(function(){ $('#scrollto').val( $('#newcontent').scrollTop() ); });
	$('#newcontent').scrollTop( $('#scrollto').val() );
});
</script>
<?php
break;
}

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