//Check if Parent/Parent Plugin is Installed
add_action( 'admin_init', 'child_plugin_has_parent_plugin' );
function child_plugin_has_parent_plugin() {
if ( is_admin() && current_user_can( 'activate_plugins' ) && !is_plugin_active( 'plugin-folder-name/plugin-filename.php' ) ) {
add_action( 'admin_notices', 'child_plugin_notice' );
deactivate_plugins( plugin_basename( __FILE__ ) );
if ( isset( $_GET['activate'] ) ) {
unset( $_GET['activate'] );
}
}
}
function child_plugin_notice(){
?><div class="error"><p>Sorry, but CHILD PLUGIN NAME requires PARENT PLUGIN NAME to be installed and active.</p></div><?php
}