Save yourself a headache and make a class. The static variable can be accessed like a global once it’s loaded. Just be sure the class exists before you try to use it!
if ( ! class_exists( 'WPSE_20150123_Plugin' ) ) {
class WPSE_20150123_Plugin {
// our variable that will be set and read back later
public static $if_autoload = 'I\'m Not Sure???';
// 'init' hook
public static function init() {
// show value
echo static::$if_autoload; // I'm quite sure
}
}
}
// set the static value
WPSE_20150123_Plugin::$if_autoload = 'I\'m quite sure!';
// hook init to static function
add_action( 'init', 'WPSE_20150123_Plugin::init' );
admin.php
Looking at your checked() function, I’m not quite sure you’re using it correctly. This is the example they give and your args look like they’re in the wrong place.
<?php
// Get an array of options from the database.
$options = get_option( 'slug_option' );
// Get the value of this option.
$checked = $options['self-destruct'];
// The value to compare with (the value of the checkbox below).
$current = 1;
// True by default, just here to make things clear.
$echo = true;
?>
<input name="slug-option[self-destruct]" value="1" <?php checked( $checked, $current, $echo ); ?>/>
Your function might work better as:
function menu_autoload_callback() {
$if_autoload = get_option( 'autoload-or-shortcode' );
echo '<input type="checkbox" name="autoload-or-shortcode" value="1" ' . checked( $if_autoload , 1, false ) . ' /><br />';
}
hooks.php
Another thing, it looks like you echo invalid html:
echo '<test>'.$if_autoload.'</test>';
should be
echo '<h1 class="test" >If Autoload: ' . $if_autoload . '</h1>';
It wouldn’t hurt to take a look at http://wppb.me.