How to include custom PHP file both in header and footer files

Question

I have created a custom file that both the header and the footer needs to render certain content.

If I only do include($_SERVER['DOCUMENT_ROOT'] . '/wp-content/themes/myTheme/myCustomFile.php'); in the header.php file it works as expected BUT only in the header.

Likewise with the footer, If I only do include($_SERVER['DOCUMENT_ROOT'] . '/wp-content/themes/myTheme/myCustomFile.php'); in the footer.php file it works as expected BUT only in the footer.

The moment I have the include on both files, the page renders up until the footer starts and then stops rendering.

How can I include this file so it can be accessed from anywhere in the theme?

I also tried the other import methods in PHP - require, require_once, and include_once – same deal.

Thank you in advance.

Answer 1

You wrote that you have a function definition in file that you include. I suspect that the reason is the function redeclaration error.

You should move the function definition from myCustomFile.php to functions.php.

You can also before each function definition in myCustomFile.php check whether there is already a function of the same name.

if ( ! function_exists('you_function_name') ) {
    function you_function_name() {
        // ...
    }
}