Title: Plugin_Installer_Skin
Published: April 25, 2014
Last modified: February 24, 2026
---
# class Plugin_Installer_Skin {}
## In this article
* [Description](https://developer.wordpress.org/reference/classes/plugin_installer_skin/?output_format=md#description)
- [See also](https://developer.wordpress.org/reference/classes/plugin_installer_skin/?output_format=md#see-also)
* [Methods](https://developer.wordpress.org/reference/classes/plugin_installer_skin/?output_format=md#methods)
* [Source](https://developer.wordpress.org/reference/classes/plugin_installer_skin/?output_format=md#source)
* [Related](https://developer.wordpress.org/reference/classes/plugin_installer_skin/?output_format=md#related)
* [Changelog](https://developer.wordpress.org/reference/classes/plugin_installer_skin/?output_format=md#changelog)
[ Back to top](https://developer.wordpress.org/reference/classes/plugin_installer_skin/?output_format=md#wp--skip-link--target)
Plugin Installer Skin for WordPress Plugin Installer.
## [Description](https://developer.wordpress.org/reference/classes/plugin_installer_skin/?output_format=md#description)
### [See also](https://developer.wordpress.org/reference/classes/plugin_installer_skin/?output_format=md#see-also)
* [WP_Upgrader_Skin](https://developer.wordpress.org/reference/classes/wp_upgrader_skin/)
## [Methods](https://developer.wordpress.org/reference/classes/plugin_installer_skin/?output_format=md#methods)
| Name | Description |
| [Plugin_Installer_Skin::__construct](https://developer.wordpress.org/reference/classes/plugin_installer_skin/__construct/) | Constructor. |
| [Plugin_Installer_Skin::after](https://developer.wordpress.org/reference/classes/plugin_installer_skin/after/) | Performs an action following a plugin install. |
| [Plugin_Installer_Skin::before](https://developer.wordpress.org/reference/classes/plugin_installer_skin/before/) | Performs an action before installing a plugin. |
| [Plugin_Installer_Skin::do_overwrite](https://developer.wordpress.org/reference/classes/plugin_installer_skin/do_overwrite/) | Checks if the plugin can be overwritten and outputs the HTML for overwriting a plugin on upload. |
| [Plugin_Installer_Skin::hide_process_failed](https://developer.wordpress.org/reference/classes/plugin_installer_skin/hide_process_failed/) | Hides the `process_failed` error when updating a plugin by uploading a zip file. |
## [Source](https://developer.wordpress.org/reference/classes/plugin_installer_skin/?output_format=md#source)
```php
class Plugin_Installer_Skin extends WP_Upgrader_Skin {
public $api;
public $type;
public $url;
public $overwrite;
private $is_downgrading = false;
/**
* Constructor.
*
* Sets up the plugin installer skin.
*
* @since 2.8.0
*
* @param array $args
*/
public function __construct( $args = array() ) {
$defaults = array(
'type' => 'web',
'url' => '',
'plugin' => '',
'nonce' => '',
'title' => '',
'overwrite' => '',
);
$args = wp_parse_args( $args, $defaults );
$this->type = $args['type'];
$this->url = $args['url'];
$this->api = isset( $args['api'] ) ? $args['api'] : array();
$this->overwrite = $args['overwrite'];
parent::__construct( $args );
}
/**
* Performs an action before installing a plugin.
*
* @since 2.8.0
*/
public function before() {
if ( ! empty( $this->api ) ) {
$this->upgrader->strings['process_success'] = sprintf(
$this->upgrader->strings['process_success_specific'],
$this->api->name,
$this->api->version
);
}
}
/**
* Hides the `process_failed` error when updating a plugin by uploading a zip file.
*
* @since 5.5.0
*
* @param WP_Error $wp_error WP_Error object.
* @return bool True if the error should be hidden, false otherwise.
*/
public function hide_process_failed( $wp_error ) {
if (
'upload' === $this->type &&
'' === $this->overwrite &&
$wp_error->get_error_code() === 'folder_exists'
) {
return true;
}
return false;
}
/**
* Performs an action following a plugin install.
*
* @since 2.8.0
*/
public function after() {
// Check if the plugin can be overwritten and output the HTML.
if ( $this->do_overwrite() ) {
return;
}
$plugin_file = $this->upgrader->plugin_info();
$install_actions = array();
$from = isset( $_GET['from'] ) ? wp_unslash( $_GET['from'] ) : 'plugins';
if ( 'import' === $from ) {
$install_actions['activate_plugin'] = sprintf(
'%s',
wp_nonce_url( 'plugins.php?action=activate&from=import&plugin=' . urlencode( $plugin_file ), 'activate-plugin_' . $plugin_file ),
__( 'Activate Plugin & Run Importer' )
);
} elseif ( 'press-this' === $from ) {
$install_actions['activate_plugin'] = sprintf(
'%s',
wp_nonce_url( 'plugins.php?action=activate&from=press-this&plugin=' . urlencode( $plugin_file ), 'activate-plugin_' . $plugin_file ),
__( 'Activate Plugin & Go to Press This' )
);
} else {
$install_actions['activate_plugin'] = sprintf(
'%s',
wp_nonce_url( 'plugins.php?action=activate&plugin=' . urlencode( $plugin_file ), 'activate-plugin_' . $plugin_file ),
__( 'Activate Plugin' )
);
}
if ( is_multisite() && current_user_can( 'manage_network_plugins' ) ) {
$install_actions['network_activate'] = sprintf(
'%s',
wp_nonce_url( 'plugins.php?action=activate&networkwide=1&plugin=' . urlencode( $plugin_file ), 'activate-plugin_' . $plugin_file ),
_x( 'Network Activate', 'plugin' )
);
unset( $install_actions['activate_plugin'] );
}
if ( 'import' === $from ) {
$install_actions['importers_page'] = sprintf(
'%s',
admin_url( 'import.php' ),
__( 'Go to Importers' )
);
} elseif ( 'web' === $this->type ) {
$install_actions['plugins_page'] = sprintf(
'%s',
self_admin_url( 'plugin-install.php' ),
__( 'Go to Plugin Installer' )
);
} elseif ( 'upload' === $this->type && 'plugins' === $from ) {
$install_actions['plugins_page'] = sprintf(
'%s',
self_admin_url( 'plugin-install.php' ),
__( 'Go to Plugin Installer' )
);
} else {
$install_actions['plugins_page'] = sprintf(
'%s',
self_admin_url( 'plugins.php' ),
__( 'Go to Plugins page' )
);
}
if ( ! $this->result || is_wp_error( $this->result ) ) {
unset( $install_actions['activate_plugin'], $install_actions['network_activate'] );
} elseif ( ! current_user_can( 'activate_plugin', $plugin_file ) || is_plugin_active( $plugin_file ) ) {
unset( $install_actions['activate_plugin'] );
}
/**
* Filters the list of action links available following a single plugin installation.
*
* @since 2.7.0
*
* @param string[] $install_actions Array of plugin action links.
* @param object $api Object containing WordPress.org API plugin data. Empty
* for non-API installs, such as when a plugin is installed
* via upload.
* @param string $plugin_file Path to the plugin file relative to the plugins directory.
*/
$install_actions = apply_filters( 'install_plugin_complete_actions', $install_actions, $this->api, $plugin_file );
if ( ! empty( $install_actions ) ) {
$this->feedback( implode( ' ', (array) $install_actions ) );
}
}
/**
* Checks if the plugin can be overwritten and outputs the HTML for overwriting a plugin on upload.
*
* @since 5.5.0
*
* @return bool Whether the plugin can be overwritten and HTML was outputted.
*/
private function do_overwrite() {
if ( 'upload' !== $this->type || ! is_wp_error( $this->result ) || 'folder_exists' !== $this->result->get_error_code() ) {
return false;
}
$folder = $this->result->get_error_data( 'folder_exists' );
$folder = ltrim( substr( $folder, strlen( WP_PLUGIN_DIR ) ), '/' );
$current_plugin_data = false;
$all_plugins = get_plugins();
foreach ( $all_plugins as $plugin => $plugin_data ) {
if ( strrpos( $plugin, $folder ) !== 0 ) {
continue;
}
$current_plugin_data = $plugin_data;
}
$new_plugin_data = $this->upgrader->new_plugin_data;
if ( ! $current_plugin_data || ! $new_plugin_data ) {
return false;
}
echo '' . esc_html__( 'This plugin is already installed.' ) . '
';
$this->is_downgrading = version_compare( $current_plugin_data['Version'], $new_plugin_data['Version'], '>' );
$rows = array(
'Name' => __( 'Plugin name' ),
'Version' => __( 'Version' ),
'Author' => __( 'Author' ),
'RequiresWP' => __( 'Required WordPress version' ),
'RequiresPHP' => __( 'Required PHP version' ),
);
$table = '';
$table .= ' | ' . esc_html_x( 'Current', 'plugin' ) . ' | ';
$table .= '' . esc_html_x( 'Uploaded', 'plugin' ) . ' |
|---|
';
$is_same_plugin = true; // Let's consider only these rows.
foreach ( $rows as $field => $label ) {
$old_value = ! empty( $current_plugin_data[ $field ] ) ? (string) $current_plugin_data[ $field ] : '-';
$new_value = ! empty( $new_plugin_data[ $field ] ) ? (string) $new_plugin_data[ $field ] : '-';
$is_same_plugin = $is_same_plugin && ( $old_value === $new_value );
$diff_field = ( 'Version' !== $field && $new_value !== $old_value );
$diff_version = ( 'Version' === $field && $this->is_downgrading );
$table .= '| ' . $label . ' | ' . wp_strip_all_tags( $old_value ) . ' | ';
$table .= ( $diff_field || $diff_version ) ? '' : ' | ';
$table .= wp_strip_all_tags( $new_value ) . ' |
';
}
$table .= '
';
/**
* Filters the compare table output for overwriting a plugin package on upload.
*
* @since 5.5.0
*
* @param string $table The output table with Name, Version, Author, RequiresWP, and RequiresPHP info.
* @param array $current_plugin_data Array with current plugin data.
* @param array $new_plugin_data Array with uploaded plugin data.
*/
echo apply_filters( 'install_plugin_overwrite_comparison', $table, $current_plugin_data, $new_plugin_data );
$install_actions = array();
$can_update = true;
$blocked_message = '' . esc_html__( 'The plugin cannot be updated due to the following:' ) . '
';
$blocked_message .= '';
$requires_php = isset( $new_plugin_data['RequiresPHP'] ) ? $new_plugin_data['RequiresPHP'] : null;
$requires_wp = isset( $new_plugin_data['RequiresWP'] ) ? $new_plugin_data['RequiresWP'] : null;
if ( ! is_php_version_compatible( $requires_php ) ) {
$error = sprintf(
/* translators: 1: Current PHP version, 2: Version required by the uploaded plugin. */
__( 'The PHP version on your server is %1$s, however the uploaded plugin requires %2$s.' ),
PHP_VERSION,
$requires_php
);
$blocked_message .= '- ' . esc_html( $error ) . '
';
$can_update = false;
}
if ( ! is_wp_version_compatible( $requires_wp ) ) {
$error = sprintf(
/* translators: 1: Current WordPress version, 2: Version required by the uploaded plugin. */
__( 'Your WordPress version is %1$s, however the uploaded plugin requires %2$s.' ),
esc_html( wp_get_wp_version() ),
$requires_wp
);
$blocked_message .= '- ' . esc_html( $error ) . '
';
$can_update = false;
}
$blocked_message .= '
';
if ( $can_update ) {
if ( $this->is_downgrading ) {
$warning = sprintf(
/* translators: %s: Documentation URL. */
__( 'You are uploading an older version of a current plugin. You can continue to install the older version, but be sure to back up your database and files first.' ),
__( 'https://developer.wordpress.org/advanced-administration/security/backup/' )
);
} else {
$warning = sprintf(
/* translators: %s: Documentation URL. */
__( 'You are updating a plugin. Be sure to back up your database and files first.' ),
__( 'https://developer.wordpress.org/advanced-administration/security/backup/' )
);
}
echo '' . $warning . '
';
$overwrite = $this->is_downgrading ? 'downgrade-plugin' : 'update-plugin';
$install_actions['overwrite_plugin'] = sprintf(
'%s',
wp_nonce_url( add_query_arg( 'overwrite', $overwrite, $this->url ), 'plugin-upload' ),
_x( 'Replace current with uploaded', 'plugin' )
);
} else {
echo $blocked_message;
}
$cancel_url = add_query_arg( 'action', 'upload-plugin-cancel-overwrite', $this->url );
$install_actions['plugins_page'] = sprintf(
'%s',
wp_nonce_url( $cancel_url, 'plugin-upload-cancel-overwrite' ),
__( 'Cancel and go back' )
);
/**
* Filters the list of action links available following a single plugin installation failure
* when overwriting is allowed.
*
* @since 5.5.0
*
* @param string[] $install_actions Array of plugin action links.
* @param object $api Object containing WordPress.org API plugin data.
* @param array $new_plugin_data Array with uploaded plugin data.
*/
$install_actions = apply_filters( 'install_plugin_overwrite_actions', $install_actions, $this->api, $new_plugin_data );
if ( ! empty( $install_actions ) ) {
printf(
'%s
',
__( 'The uploaded file has expired. Please go back and upload it again.' )
);
echo '' . implode( ' ', (array) $install_actions ) . '
';
}
return true;
}
}
```
[View all references](https://developer.wordpress.org/reference/files/wp-admin/includes/class-plugin-installer-skin.php/)
[View on Trac](https://core.trac.wordpress.org/browser/tags/6.9.4/src/wp-admin/includes/class-plugin-installer-skin.php#L18)
[View on GitHub](https://github.com/WordPress/wordpress-develop/blob/6.9.4/src/wp-admin/includes/class-plugin-installer-skin.php#L18-L355)
## [Related](https://developer.wordpress.org/reference/classes/plugin_installer_skin/?output_format=md#related)
| Uses | Description |
| [WP_Upgrader_Skin](https://developer.wordpress.org/reference/classes/wp_upgrader_skin/)`wp-admin/includes/class-wp-upgrader-skin.php` |
Generic Skin for the WordPress Upgrader classes. This skin is designed to be extended for specific purposes.
|
## [Changelog](https://developer.wordpress.org/reference/classes/plugin_installer_skin/?output_format=md#changelog)
| Version | Description |
| [4.6.0](https://developer.wordpress.org/reference/since/4.6.0/) | Moved to its own file from wp-admin/includes/class-wp-upgrader-skins.php. |
| [2.8.0](https://developer.wordpress.org/reference/since/2.8.0/) | Introduced. |
## User Contributed Notes
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