Eloquent Specify Relation Columns of belongsToMany relationship - json

Question

I have tried all kinds of methods of limiting the columns which are returned in my many-to-many relationship, and none seem to work.
Background - Not really necessary, but to give the big picture
Essentially, in my app, I want to build a list of contacts for the currently logged in user. Administrator and Billing users should be able to contact everybody including users of group Customer.
Customer should only be able to contact Administrator and Billing.
So my way to tackle this is firstly to determine the groups that the user is in.
$userGroups = Sentry::getUser()->getGroups()->lists('name', 'id');
Then iterate over the groups, to see if the user is in the group Administrator or Billing or Customer and build the contact groups for that user.
foreach($userGroups as $group)
{
if ($group === 'Administrator' || $group === 'Billing')
{
$contactGroups = \Group::with('users')->get(['id', 'name']);
}
else if ($group === 'Customer')
{
$contactGroups = \Group::where('name', 'Administrator')
->orWhere('name', 'Billing')
->with('users')
->get(['id', 'name']);
}
else
{
return Response::json('No Contacts found', 404);
}
}
The problem - It appears that I am unable to select specific columns to select on belongsToMany relations.
I have tried:
$contactGroups = \Group::where('name', 'Administrator')
->orWhere('name', 'Billing')
->with(['users', function($q){
$q->select('id', 'first_name', 'last_name');
}])
->get(['id', 'name']);
I have also tried limiting the select within the Group model
class Group extends Eloquent
{
protected $table = 'groups';
public function users()
{
return $this->belongsToMany('User', 'users_groups')
->select('id', 'first_name', 'last_name', 'email', 'telephone');
}
}
Either way, the query runs, but it returns the entire user object and completely ignores my selects.
As such, when I return a json response, everything that I do not want is included.
So what I have done as a temporary fix is iterate over each of the users in each of the groups, and unset all the attributes which I do not want.
foreach ($contactGroups as $group)
{
foreach($group->users as $user)
{
unset($user->persist_code);
unset($user->created_at);
unset($user->updated_at);
unset($user->deleted_at);
unset($user->last_login);
unset($user->permissions);
unset($user->activated_at);
unset($user->activated);
unset($user->reset_password_code);
unset($user->pivot);
}
}
return Response::json($contactGroups, 200);
This is really clunky, inefficient and seems like a waste of time. Is there a better way of achieving the above?

Answer 1

For some reason selecting specific columns with belongsToMany is not working.
But i have found an alternate solution.
There is a provision in laravel, Converting to Arrays or json that allows you to whitelist/blacklist specific columns when using toArray() or toJson.
To prevent specific fields from appearing in the relation :
class User extends Eloquent{
protected $hidden = array("persist_code","created_at","updated_at","deleted_at","last_login");
}
Instead if you wish to allow specific fields :
protected $visible = array("Visibile fields");

Answer 2

try this
$contactGroups = \Group::where('name', 'Administrator')
->orWhere('name', 'Billing')
->with(['users', function($q){
$q->get(['id', 'first_name', 'last_name']);
}])
->get(['id', 'name']);
or this
$contactGroups = \Group::where('name', 'Administrator')
->orWhere('name', 'Billing')
->with(['users:id,first_name,last_name'])
->get(['id', 'name']);