Laravel Eloquent: hasManyThrough Many to Many relationship - php

Question

I have the following classes (simplified here) in my Laravel 5.7 model:
VEHICLE.PHP
<?php
namespace App;
use Illuminate\Database\Eloquent\Model;
class Vehicle extends Model
{
public function journeys()
{
return $this->hasMany('App\Journey');
}
}
JOURNEY PHP
<?php
namespace App;
use Illuminate\Database\Eloquent\Model;
class Journey extends Model
{
public function vehicle()
{
return $this->belongsTo('App\Vehicle');
}
public function users()
{
return $this->belongsToMany('App\User');
}
}
USER.PHP
<?php
namespace App;
use Illuminate\Database\Eloquent\Model;
class User extends Model
{
public function journeys()
{
return $this->belongsToMany('App\Journey');
}
}
I have an intermediate table (journey_user) between users and journeys (see schema attached).
I can easily get all journeys made by a particular user. But how can I get all vehicles used by a particular user? The standard hasManyThrough method does not appear to work because of the Many to Many relationship between users and journeys.
Thanks for your help!

Answer 1

I haven't tested this out. However, it should be possible to get all vehicles by looping through all the user's journeys, creating an array of vehicles and return this as a collection.
This can be added to your User.php model controller:
/**
* Get all vehicles which user has used
*
*/
public function vehicles()
{
$vehicles = [];
$this->journeys()
->each(function ($journey, $key) use (&$vehicles) {
$vehicles[] = $journey->vehicle;
});
return collect($vehicles);
}
Here, we create an empty array. Then we loop through all the journeys of the users (passing the $vehicles array as a reference to update it).
We use the each() collection method to loop through each journey. We create a new entry to the $vehicles array, adding the vehicle.
Finally, we return all vehicles as a collection.
We can use this in our application like so:
User::find($id)->vehicles();
Note: You could return this as an accessor attribute by changing the function name to setVehiclesAttribute(). This will allow you to access the vehicle field like User::find($id)->vehicle.