It might be better if you tell me what you are trying to accomplish, from the looks for it you want to create prefixes for your own custom blog plugin?
In which case, you might be better off creating your own datawriter
The datawriter that you are using is the core one (look at the file \library\XenForo\DataWriter\ThreadPrefix.php), so it expects the following:
PHP:
'prefix_id' => array('type' => self::TYPE_UINT, 'autoIncrement' => true),
'prefix_group_id' => array('type' => self::TYPE_UINT, 'default' => 0),
'display_order' => array('type' => self::TYPE_UINT_FORCED, 'default' => 0),
'materialized_order' => array('typpe' => self::TYPE_UINT_FORCED, 'default' => 0),
'css_class' => array('type' => self::TYPE_STRING, 'maxLength' => 50, 'default' => ''),
'allowed_user_group_ids' => array('type' => self::TYPE_UNKNOWN, 'default' => '',
'verification' => array('$this', '_verifyAllowedUserGroupIds')
node_id and title is not present here (so this will throw an error if you try to use this datawriter to save them)... as you have seen
The $minTitle that you are trying to save I assume is the thread prefix title?
To make this easy to follow, just attempt to create a new thread_prefix (and see where the form gets submitted)
You will find the form gets submited to "admin.php?thread-prefixes/save"
We can look at the routes to see what file "thread-prefixes/save" is in, but a good guess might be that it's within a file name ThreadPrefixes using a function : actionSave() and that file is within the ControllerAdmin (since we are in the ACP)
hence: XenForo_ControllerAdmin_ThreadPrefix
And then find this function: actionSave()
(please look at this file, its all in there: library\XenForo\ControllerAdmin\ThreadPrefix.php)
So for the datawriter: XenForo_DataWriter_ThreadPrefix
you need to set:
Code:
$dw->bulkSet(array(
'prefix_group_id' => $input['prefix_group_id'],
'display_order' => $input['display_order'],
'css_class' => $input['css_class'],
'allowed_user_group_ids' => $allowedGroupIds
));
and then to set the title, you need to use
Code:
$dw->setExtraData(XenForo_DataWriter_ThreadPrefix::DATA_TITLE, $input['title']);
and then $dw->save();
You will also need to associate it to a forum node_id if you expect to use it within a give forum
Code:
$this->_getPrefixModel()->updatePrefixForumAssociationByPrefix($dw->get('prefix_id'), $input['node_ids']);