how can I link to a PlugIn admin-sub-menu page after processing a formular

Question

I have a Plugin with 3 submenu_pages. In one page is a formular (in one some text and in one a list of items). when I submit the form, there will be done some processing. after that I don't want to get back to the form-page, but WP shell redirect me to one of the other submenu_pages (in this case a list).

how can I achive this?

add_menu_page( 'page1 main page', '0', 'manage_options', 'mg-pi', 'mg_backend');    
add_submenu_page( 'mg-pi', 'list smthing', '0', 'manage_options', 'mg-pi-sub-list', 'mg_list');
add_submenu_page( 'mg-pi', 'create', '0', 'manage_options', 'mg-pi-sub-create', 'mg_new_item');   

so in mg_new_item() is the processing and then it shell redirect to mg_list(). but if I do the php call to mg_list() the url is still the one of mg_new_item().

I know I could do some header("Location: the-hardcoded-list-url"); but I am looking for the WordPress common way of doing it, with generic Url generation.

Answer 1

Simply use add_query_arg(), remove_query_arg() and get_query_var().

On your page link, you use a simple query var like step=one.

$query_arg = add_query_arg( 'step', 'one', $_SERVER['REQUEST_URI'] );

Then, when the user processed the form, you just reload the page. Then simply check if

0 !== get_query_var( 'step' )
AND 'one' !== get_query_var( 'step' )

and process further. If you want to go back, just use remove_query_arg(), etc.

Answer 2

Well after some more research I fond what I was actually looking for. Not for a workaround but for a wordpress compatible way.

There is a function called: menu_page_url which expects the defined slug. and there is wp_redirect

so we have 2 wordpress functions to call. In this case:

$foo = menu_page_url("mg-pi-sub-list");
wp_redirect($foo);

that's it. And the good thing, I observe all Wordpress rules and the plugin will be compatible in future versions.

http://codex.wordpress.org/Function_Reference/wp_redirect http://codex.wordpress.org/Function_Reference/menu_page_url

UPDATE

and if you have troubles with your headers you can help you out with this parameter:

<form action="?page=your-sub_page-slug&noheaders=true">