This is an old revision of the document!
Piwigo has a graphical interface for the administration panel, where many options can be easily changed in only a few clicks. But Piwigo allows much more customizations. In order to keep the essential options easily identifiable, all these additional options are not available in the graphical interface but in a file. The default config file, which should be never modified, is include/config_default.inc.php : it's an essential file, and you can open it to see what are the available additional options, but not to modify them!
The best way is to use the plugin LocalFiles Editor, available as a default plugin in any Piwigo installation :
The Local Config use a PHP syntax:
$conf['NAME OF THE VARIABLE'] = VALUE_OF_THE_VARIABLE;
For example
$conf['top_number'] = 15;
$conf['comment_spam_reject'] = true;
$conf['newcat_default_status'] = 'public';
The workflow:
newcat_default_visible : at creation, must a category be visible or not ?
Warning : if the parent category is invisible, the category is
automatically create invisible. (invisible = locked)
$conf['newcat_default_visible'] = true;
$conf['newcat_default_visible'] = true;
File written successfully. Backup file created (local/config/config.inc.bak.php)