Override parent theme's include file from child theme

Question

I am trying to override a parent theme's include file from a child theme. Here is the code:

parentTheme/functions.php

<?php



define ( "_CRYOUT_THEME_NAME", "fluida" );
define ( "_CRYOUT_THEME_VERSION", "1.2.6" );

require_once( get_template_directory() . "/admin/main.php" );
require_once( get_template_directory() . "/includes/setup.php" );
require_once( get_template_directory() . "/includes/styles.php" );
require_once( get_template_directory() . "/includes/loop.php" );
require_once( get_template_directory() . "/includes/comments.php" );
require_once( get_template_directory() . "/includes/core.php" );
require_once( get_template_directory() . "/includes/hooks.php" );
require_once( get_template_directory() . "/includes/meta.php" );
require_once( get_template_directory() . "/includes/landing-page.php" );

childTheme/functions.php

<?php

add_action( 'wp_enqueue_scripts', 'my_theme_enqueue_styles' );
function my_theme_enqueue_styles() {
    wp_enqueue_style( 'parent-style', get_template_directory_uri() . '/style.css' );
}

?>

And I want to override the /includes/core.php file
I have a childTheme/includes/core.php file
But when I change it, there are no changes on my site.
I have tried to add this code on my childTheme/functions.php :

require_once( get_stylesheet_directory() . "/includes/core.php");

But it renders a blank page on my site.

EDIT :

I have tryed this :

<?php
/**
* Enqueues child theme stylesheet, loading first the parent theme stylesheet.
*/
require_once( get_stylesheet_directory() . "/includes/core.php" );        // Core functions

function themify_custom_enqueue_child_theme_styles() {
    wp_enqueue_style( 'parent-theme-css', get_template_directory_uri() . '/style.css' );
}
add_action( 'wp_enqueue_scripts', 'themify_custom_enqueue_child_theme_styles', 11 );

But I got this error :

Cannot redeclare xxx_function_name 
(previously declared in /var/www/html/mywebsite/wp-content/themes/***childTheme***/includes/core.php:340)
in /var/www/html/tpevegetarisme/wp-content/themes/***parentTheme***/includes/core.php on line 340

So how can I do to prevent parent theme to redeclare a function

Answer 1

You cannot simply override that file.

You can however override what the core.php file does:

Use remove_filter / remove_action to remove filters you do not want to be run:

remove_action ( 'cryout_headerimage_hook', 'fluida_header_image' );