WordPress functions.php - Admin html injection and submitting forms

Question

I created a new navigation item on the left for my WP Admin:

add_action( 'admin_menu', 'addManagementMenuItem' );


function addManagementMenuItem(){

add_menu_page('Issue Management', 'Issue Management', 'manage_options', 'issue_management_slug', 'issue_management_building_function','',3);

} 


function issue_management_building_function(){

if(!current_user_can('manage_options')){

}
else {
    ?>
...
...

So where I have the ellipsis ... is where my HTML begins and I write out some information to the page with various php echo statements to print some data out.

What I would like to do is now give the user the ability to enter in a filter and press submit. This would issue a POST to another page which would receive the post data, run some stuff, and spit out something else to the screen. I was just thinking this would take the user away from the WP-ADMIN area entirely (what I want to do is keep the user all within the right pane so it looks like it's natively happening on WordPress under my new admin area)

Something feels wrong about this approach above where I'm putting tons of html into functions.php - what is the way to create pages for a custom admin section where I can do things like post forms and go to multiple pages?

I was thinking the best solution would be to put an iframe in my injected HTML in functions.php, and then the pages can talk to themselves just like normal behind the scenes in WP-admin.

Could anyone point me in the right direction?

thanks!

Answer 1

Considering the user input/_POST features you'd like to add to this, you may want to consider building this functionality out as your own plugin. I've always kept custom functionality limited to non-user interaction in the functions.php file, but anything further would probably be better fit as it's own plugin.

For example, what if you created a plugin directory named nullhypothesis:

add_action( 'admin_menu', 'addManagementMenuItem' );

function addManagementMenuItem(){
add_menu_page('Issue Management', 'Issue Management', 'manage_options', 'nullhypothesis/file_to_do_your_bidding.php', 'issue_management_building_function','',3);
} 

It's that fourth parameter that in the documentation mentions that you should include the menu_slug, but it doesn't necessarily need to only be a function - it can also be a file you define.

Then, in your file_to_do_your_bidding.php file (within your plugin), you can add whatever _POST functionality you'd need it to. It could also exist as the 'admin' page that the administrator/whoever interacts with.

Was that what you were looking for?