All in the subject : How to detect when a relation instance is added or deleted from a model ?

My test case is simple: I need to detect when a model 'project' is added/deleted to a model 'developer', A developer belongsToMany projects

I know about the beforeSave() events method but that does not seems to apply on a relation.

Thanks for any help

I found this approach working quite well

in your plugin.php, I need to create a log entry when a file is uploaded or remove from a relationship on a model Round

function boot() {

        \System\Models\File::extend(function($model) {
            $model->bindEvent('model.afterSave', function() use ($model) {
                if('XYZ\Models\Round' == $model->attachment_type) {
                    if ($round = Round::find($model->attachment_id)) {
                        $round->addLogEntry('File added');
                        $round->save();
                    }
                }
            });
            $model->bindEvent('model.afterDelete', function() use ($model) {
                if('XYZ\Models\Round' == $model->attachment_type) {
                    if ($round = Round::find($model->attachment_id)) {
                        $round->addLogEntry('File removed');
                        $round->save();
                    }
                }
            });
        });
}