Not in functions.php

[gwuluo]

Does it have to be in functions.php? It is not executed in other php, how should I write it? Thank you

[YahnisElsts]

No, it doesn't have to be in functions.php. You can put the code that initializes the update checker in a different file, but you need to be careful to pass the correct file path to the buildUpdateChecker() method. The second argument should be the full path to a file in your theme's main directory, like functions.php or style.css. If the code is in functions.php you can just use the __FILE__ constant, but in a different file, you'll need another solution.

How you do that is up to you. For example, you could define a new constant in your functions.php, like

defined('MY_THEME_FUNCTIONS_PHP_FILE', __FILE__);

... and then pass that to the update checker:

$myUpdateChecker = Puc_v4_Factory::buildUpdateChecker(
    'http://example.com/path/to/details.json',
    MY_THEME_FUNCTIONS_PHP_FILE,
    'unique-plugin-or-theme-slug'
);

[gwuluo]

Thank you very much.