In api controller, don't define $json variable in models

[pascalchevrel]

instead of doing that:
Controller:

include MODELS . 'api/repository_locales.php';
...
include VIEWS . 'json.php';

Model:

return $json = foo();

Which includes a $json variable that we use in the view.

Let's do that:
Controller:

$json = include MODELS . 'api/repository_locales.php';
...
include VIEWS . 'json.php';

Model:

return foo();

That will bring more clarity as to where this $json value is defined as it will be defined in a single file.