在Laravel 5中更新其他数据透视表值

Question

I'm building a friendship system in Laravel 5 that requires a user to accept a potential friendship with another user.

I've created a many-to-many relationship between users and "helpers" (other users). The relationships look like this:

// Accepted Friendships
function friendsOfMine()
{
  return $this->belongsToMany('App\User', 'helpers', 'user_id', 'helper_id')
    ->wherePivot('accepted', '=', 1);
}

// Potential Friendships
function potentialFriendsOfMine()
{
  return $this->belongsToMany('App\User', 'helpers', 'user_id', 'helper_id')
    ->wherePivot('accepted', '=', 0);
}

The only difference between them is an additional value in my "helpers" pivot table: "accepted." "Accepted" is a boolean that defaults to 0.

I create the table row when a user first proposes friendship, and then would like to update the row when the friendship is accepted. Here is a version of my controller that condenses the two actions into a single code block:

public function store()
{
    $currentUser = Auth::user();
    $input = Input::get('helper_id');
    $helper = User::find($input);

    /* Creates "unaccepted" relationship */
    $currentUser->friendsOfMine()->attach($helper);

    /* Fetches newly created relationship */
    $accepted = $currentUser->potentialFriendsOfMine()->where('helper_id', $input);

    /* Updates "accepted" column and saves */
    $accepted->pivot->accepted = 1;
    $accepted->pivot->save();
    Flash::success('You are now following this user.');
    return Redirect::back();
}

However, I'm getting an error on this line—$accepted->pivot->accepted = 1;—that reads: Creating default object from empty value.

In this case, how would I access and update a value in a pivot table record that I just created?

Answer 1

This line: $accepted = $currentUser->potentialFriendsOfMine()->where('helper_id', $input); returns a Builder object. I think you have forgotten to add ->get() at the end to get a model object. In other words:

$accepted = $currentUser->potentialFriendsOfMine()->where('helper_id', $input)->get();

OR

$accepted = $currentUser->potentialFriendsOfMine()->where('helper_id', $input)->first();