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filter is not described

wp_theme_editor_filetypes filter-hook . WP 4.4.0

Filters the list of file types allowed for editing in the Theme editor.

Usage

add_filter( 'wp_theme_editor_filetypes', 'filter_function_name_7592', 10, 2 );
function filter_function_name_7592( $default_types, $theme ){
	// filter...

	return $default_types;
}
$default_types(array)
List of file types.
Default: types include 'php' and 'css'
$theme(WP_Theme)
The current Theme object.

Where the hook is called

wp_get_theme_file_editable_extensions()
wp-admin/includes/file.php 283
$file_types = apply_filters( 'wp_theme_editor_filetypes', $default_types, $theme );

Where the hook is used (in WP core)

Does not used.