WordPress - Including a variable in get_header does not work

Question

For some reason whenever I try to put a variable in get_header in my custom page.php in WordPress, it doesn't recognise the value and resets to default.

Here's my code:

$header_choice = of_get_option( 'headerstyle', 'default' );
get_header( $header_choice );

of_get_option is a function from Options Framework

This because I'm using multisite and it would be great if power users can change the header themselves per-site without having to dive into the code or having to ask us, the developers.

How can I use a variable in get_header so I can dynamically assign the value?

Answer 1

You're running into a variable scope issue. WordPress is including the header via it's own function get_header() and your template variables aren't available. You might find other folks recommending you just use include('header.php') but you don't want to do that either. (get_header() triggers other WordPress specific actions and it's important to keep it).

You have a couple of options, and one of them is my preference.

First, you can use the global keyword to hoist your variable into the global scope like so:

global $header_choice = of_get_option( 'headerstyle', 'default' );
get_header();

Then, inside header.php you would access it again using the global keyword like so:

// from inside header.php
global $header_choice;
if ($header_choice == 'some_option') {
    // do some work
}

But this pollutes the global scope a bit (and it can get to be disorganized, especially if you begin using globals in other pages and for other things). So you can also scope your globals using the $GLOBALS array and nest all of your theme's globals into their own "namespaced" array like so:

Inside functions.php initialize your $GLOBALS variable

// from inside functions.php
$GLOBALS['THEME_NAME'] = array();

In your template file, initialize your theme options

$GLOBALS['THEME_NAME'] = array();
$GLOBALS['THEME_NAME']['header_choice'] = of_get_option( 'headerstyle', 'default' );
get_header();

In your header.php file you access it simply like so:

// from inside header.php
if ($GLOBALS['THEME_NAME']['header_choice'] == 'some_option') {
    // do some work
}