Protect pivot table from mass assignment using eloquent

[lauren89]

Hi

I have following tables:

document: id, name;
author: id, name, job_title;
document_author: document_id, author_id, position

I'm passing an array of following structure:

$attributes = [name, job_title, position]; 

I'm trying to create author's model and attach it to document:

$author = \Author::create($attributes);
\Document::find($id)->authors()->save($author,$attributes);

Then I get QueryException, because laravel tries to mass assign attributes to pivot table, while it should only pass a position field.

The only I got is to filter array, like that:

$author = \Author::create($attributes);
$pivotAttributes = array_only($attributes, ['position'])
\Document::find($id)->authors()->save($author,$pivotAttributes);

Is there any better way, to define which columns of pivot table are fillable, better somewhere in the model or in it's relation?