Override custom-logo parameters in WordPress child theme

Question

I'm making a child theme based off of Shapely. In Shapely's functions.php, custom-logo support is declared.

/**
     * Add support for the custom logo functionality
     */
    add_theme_support( 'custom-logo', array(
        'height'     => 55,
        'width'      => 136,
        'flex-width' => true,
    ) );

In my child theme's functions.php, I tried writing:

function override_shapely_customlogo() {
    add_theme_support( 'custom-logo', array(
       'width'      => 168,
       'flex-height' => true,
    ) );
}
add_action( 'after_setup_theme', 'override_shapely_customlogo' );

But this doesn't appear to do anything.

Is there a way for a child theme to override custom logo support parameters?

Answer 1

Took a bit of digging and I definitely encountered some false leads, but I got there. Turns out that you can absolutely override theme_support functions. However, your code has the exact same priority and action hook as Shapely's, so whichever code executes last wins out.

And (here's the bit that took some research) the functions.php of a child theme actually gets executed before the parent theme's:

[T]he functions.php of a child theme does not override its counterpart from the parent. Instead, it is loaded in addition to the parent’s functions.php. (Specifically, it is loaded right before the parent’s file.)

From the Codex, emphasis mine. Therefore, all we have to do is give your code a higher level of execution priority.

<?php
function override_shapely_customlogo() {
        add_theme_support( 'custom-logo', array(
             'width'      => 168,
             'flex-height' => true,
        ) );
}
add_action( 'after_setup_theme', 'override_shapely_customlogo', 11 );
?>

Edit: just wanted to add, the reason why I went with priority 11 here is that 10 is the default priority on add_action(): https://developer.wordpress.org/reference/functions/add_action/#parameters