functions - Why get_header() or get_footer() does not run twice if called in the same php file?

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I'm curious that why the get_header() or get_footer() function does not show output if called twice in the same .php file??

I tried to call the get_header() twice in my single.php file it runs fine but on the front end it shows output only once, what is the reason?

I'm curious that why the get_header() or get_footer() function does not show output if called twice in the same .php file??

I tried to call the get_header() twice in my single.php file it runs fine but on the front end it shows output only once, what is the reason?

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• hooks

Share Improve this question asked Dec 1, 2020 at 20:19 Rishi MalviyaRishi Malviya 3133 bronze badges

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2 Answers 2

Sorted by: Reset to default 3

The actual templates are loaded with require_once, so PHP automatically ignores the second attempt to load them. (You will trigger the 'get_header' hook twice though.)

Here's the relevant code in get_header():

    $templates[] = 'header.php';

    if ( ! locate_template( $templates, true, true, $args ) ) {
        return false;
    }

The third parameter to locate_header(), the second true, is the load-with-require-once flag. There's no filter we can use to change that behaviour here.

Note that you could include two different header templates, e.g. if you created a copy of header.php as header-duplicate.php in your theme then

get_header();
get_header('duplicate');

would include them both, as this wouldn't get blocked by require_once.

The reason for this is simple:

It's not ment to be called twice!

The get_header() function loads all necessary scripts and styles for the page to be fully working. That also means all plugin files, and all Hooks or Filters that are ment to be loaded for the header.

Though I have never tried this, I guess that WordPress is skipping all scripts, when it is being called a second time. You cannot include twice for instance.

Same goes for the get_footer() function.

Quote from core docs:

Includes the header template for a theme or if a name is specified then a specialised header will be included.

For the parameter, if the file is called "header-special.php" then specify "special".

Meaning, that you may load a different part of your header, in case you need to.

If you want to include some scripts, use wp_enqueue_scripts(). If you want to include some different template parts, use get_template_part().

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