add nested relation support for related() method (#110)

closes #105

src/ModelFilter.php

@@ -351,9 +351,30 @@ public function relationIsJoined($relation)
      */
     public function getRelatedModel($relation)
     {
+        if (strpos($relation, '.') !== false) {
+            return $this->getNestedRelatedModel($relation);
+        }
+
         return $this->query->getModel()->{$relation}()->getRelated();
     }
 
+    /**
+     * @param $relationString
+     * @return QueryBuilder|\Illuminate\Database\Eloquent\Model
+     */
+    protected function getNestedRelatedModel($relationString)
+    {
+        $parts = explode('.', $relationString);
+        $related = $this->query->getModel();
+
+        do {
+            $relation = array_shift($parts);
+            $related = $related->{$relation}()->getRelated();
+        } while (! empty($parts));
+
+        return $related;
+    }
+
     /**
      * Get the table name from a relationship.
      *

tests/ModelFilterChildTest.php

@@ -1,13 +1,12 @@
 <?php
 
 use EloquentFilter\TestClass\Client;
+use EloquentFilter\TestClass\Location;
 use EloquentFilter\TestClass\User;
 use EloquentFilter\TestClass\UserFilter;
 use Illuminate\Database\Connectors\ConnectionFactory;
 use Illuminate\Database\DatabaseManager;
-use Illuminate\Database\Eloquent\Builder;
 use Illuminate\Database\Eloquent\Model;
-use Illuminate\Database\Eloquent\Relations\HasMany;
 use Illuminate\Database\Schema\Builder as SchemaBuilder;
 use Mockery as m;
 use PHPUnit\Framework\TestCase;
@@ -39,19 +38,11 @@ public function tearDown()
 
     public function testGetRelatedModel()
     {
-        $userMock = m::mock(User::class);
-        $userQueryMock = m::mock(Builder::class);
-        $hasManyMock = m::mock(HasMany::class);
-
-        $userQueryMock->shouldReceive('getModel')->once()->andReturn($userMock);
-
-        $userMock->shouldReceive('clients')->once()->andReturn($hasManyMock);
-
-        $hasManyMock->shouldReceive('getRelated')->once()->andReturn(new Client);
-
-        $client = (new UserFilter($userQueryMock))->getRelatedModel('clients');
-
-        $this->assertEquals($client, new Client);
+        $filter = new UserFilter($this->model->newQuery());
+        // Regular relation
+        $this->assertInstanceOf(Client::class, $filter->getRelatedModel('clients'));
+        // Nested relation
+        $this->assertInstanceOf(Location::class, $filter->getRelatedModel('clients.locations'));
     }
 
     public function testProvideFilter()
@@ -70,6 +61,12 @@ public function testGetModelFilterClass()
         $this->assertEquals($this->model->getModelFilterClass(), EloquentFilter\TestClass\UserFilter::class);
     }
 
+    public function testRelationDotNotation()
+    {
+        $users = $this->model->filter(['client_location' => 'one'])->get();
+        $this->assertEquals(1, $users->count());
+    }
+
     public function testPaginationWorksOnBelongsToMany()
     {
         if (method_exists(\Illuminate\Database\Eloquent\Relations\Relation::class, 'macro')) {
@@ -130,7 +127,10 @@ protected function dbSetup()
 
         $clients = [['name' => 'one'], ['name' => 'two'], ['name' => 'three'], ['name' => 'four']];
         foreach ($clients as $index => $data) {
+            /** @var Client $client */
             $client = Client::create($data);
+            $client->locations()->create($data);
+            /** @var User $user */
             $user = User::create(['name' => 'Client'.$index]);
             $user->clients()->save($client);
             $client->managers()->save($user);

tests/classes/Client.php

@@ -27,4 +27,9 @@ public function managers()
     {
         return $this->belongsToMany(User::class);
     }
+
+    public function locations()
+    {
+        return $this->hasMany(Location::class);
+    }
 }

tests/classes/Location.php

@@ -0,0 +1,17 @@
+<?php
+
+namespace EloquentFilter\TestClass;
+
+use Illuminate\Database\Eloquent\Model;
+
+class Location extends Model
+{
+    protected $fillable = ['name'];
+
+    public $timestamps = false;
+
+    public function client()
+    {
+        return $this->belongsTo(Client::class);
+    }
+}

tests/classes/UserFilter.php

@@ -25,4 +25,9 @@ public function clientsSetup()
     {
         return $this;
     }
+
+    public function clientLocation($location)
+    {
+        $this->related('clients.locations', 'name', $location);
+    }
 }