WordPress Version: 5.3
//
// Pages
//
/**
* Retrieve or display a list of pages as a dropdown (select list).
*
* @since 2.1.0
* @since 4.2.0 The `$value_field` argument was added.
* @since 4.3.0 The `$class` argument was added.
*
* @see get_pages()
*
* @param array|string $args {
* Optional. Array or string of arguments to generate a page dropdown. See `get_pages()` for additional arguments.
*
* @type int $depth Maximum depth. Default 0.
* @type int $child_of Page ID to retrieve child pages of. Default 0.
* @type int|string $selected Value of the option that should be selected. Default 0.
* @type bool|int $echo Whether to echo or return the generated markup. Accepts 0, 1,
* or their bool equivalents. Default 1.
* @type string $name Value for the 'name' attribute of the select element.
* Default 'page_id'.
* @type string $id Value for the 'id' attribute of the select element.
* @type string $class Value for the 'class' attribute of the select element. Default: none.
* Defaults to the value of `$name`.
* @type string $show_option_none Text to display for showing no pages. Default empty (does not display).
* @type string $show_option_no_change Text to display for "no change" option. Default empty (does not display).
* @type string $option_none_value Value to use when no page is selected. Default empty.
* @type string $value_field Post field used to populate the 'value' attribute of the option
* elements. Accepts any valid post field. Default 'ID'.
* }
* @return string HTML content, if not displaying.
*/
function wp_dropdown_pages($args = '')
{
$defaults = array('depth' => 0, 'child_of' => 0, 'selected' => 0, 'echo' => 1, 'name' => 'page_id', 'id' => '', 'class' => '', 'show_option_none' => '', 'show_option_no_change' => '', 'option_none_value' => '', 'value_field' => 'ID');
$parsed_args = wp_parse_args($args, $defaults);
$pages = get_pages($parsed_args);
$output = '';
// Back-compat with old system where both id and name were based on $name argument
if (empty($parsed_args['id'])) {
$parsed_args['id'] = $parsed_args['name'];
}
if (!empty($pages)) {
$class = '';
if (!empty($parsed_args['class'])) {
$class = " class='" . esc_attr($parsed_args['class']) . "'";
}
$output = "<select name='" . esc_attr($parsed_args['name']) . "'" . $class . " id='" . esc_attr($parsed_args['id']) . "'>\n";
if ($parsed_args['show_option_no_change']) {
$output .= "\t<option value=\"-1\">" . $parsed_args['show_option_no_change'] . "</option>\n";
}
if ($parsed_args['show_option_none']) {
$output .= "\t<option value=\"" . esc_attr($parsed_args['option_none_value']) . '">' . $parsed_args['show_option_none'] . "</option>\n";
}
$output .= walk_page_dropdown_tree($pages, $parsed_args['depth'], $parsed_args);
$output .= "</select>\n";
}
/**
* Filters the HTML output of a list of pages as a drop down.
*
* @since 2.1.0
* @since 4.4.0 `$parsed_args` and `$pages` added as arguments.
*
* @param string $output HTML output for drop down list of pages.
* @param array $parsed_args The parsed arguments array.
* @param array $pages List of WP_Post objects returned by `get_pages()`
*/
$html = apply_filters('wp_dropdown_pages', $output, $parsed_args, $pages);
if ($parsed_args['echo']) {
echo $html;
}
return $html;
}