require/include php file in add_menu()

Question

I'm creating a custom WP Admin Bar menu item with custom HTML inside the dropdowns. Referring to this: https://codex.wordpress.org/Class_Reference/WP_Admin_Bar/add_menu

the HTML i want to use is quite extensive so I created a separate php file for that HTML. Then I'm trying to include that PHP file inside the menu item, but it's not printing/echoing properly. Right now, all the shows inside the menu item is a 1, and the content is getting printed later on in the DOM of the page.

Here's the code I have:

$admin_bar->add_menu( 
    array(
        'id'    => 'dh_row_layouts-content',
        'parent' => 'dh_row_layouts',
        'meta'  => array(        
            'class' => 'dh_hack',
            'html' => include('docs/row_layouts.php'),
        ),
    )
);

Any ideas?

Answer 1

You can turn on output buffering, include (and evaluate) the PHP file, and save the output (of the evaluated code) in a variable, like so:

ob_start();
include 'docs/row_layouts.php';
$html = ob_get_clean();

Then just use 'html' => $html in the meta array when you call the $admin_bar->add_menu().

Or if you don't need to evaluate any PHP code in the file, you could use file_get_contents():

'html' => file_get_contents( 'docs/row_layouts.php' )

And you may need to or better use a full absolute path.