How to set the keep me logged in box to true in Mediawiki Special:UserLogin

Question

Can you force (or at least prompt) new users to keep themselves logged in?

In order to reduce the likelihood of losing work, I would like the Special:UserLogin page to appear as

Answer 1

You can probably use $wgDefaultUserOptions['rememberpassword'] = 1. See $wgDefaultUserOptions (and also $wgHiddenPrefs).

Answer 2

(MediaWiki 1.31.0) Add to LocalSettings.php:

$wgHooks['AuthChangeFormFields'][] = function ($requests, $fieldInfo, &$formDescriptor, $action) {
  $formDescriptor['rememberMe']['default'] = true;
  return true;
};

See Hooks/AuthChangeFormFields and HTMLForm.

Answer 3

The above answer will now throw fatal exception on Special:CreateAccount if anybody attempts account creation. You have to define the HTML form class. Something like this:

// Check the password "remember me" box by default (sitewide)
$wgHooks['AuthChangeFormFields'][] = function ($requests, $fieldInfo, &$formDescriptor, $action) {
    $formDescriptor['rememberMe'] = ['type' => 'check', 'default' => true ];
    return true;
};