Add support to make relation for ObjectID with hasMany and hasOne m…

…ongodb#2

src/Jenssegers/Mongodb/Relations/EmbedsOneOrMany.php

@@ -82,6 +82,7 @@ public function match(array $models, Collection $results, $relation)
     {
         foreach ($models as $model) {
             $results = $model->$relation()->getResults();
+            dd($results);
 
             $model->setParentRelation($this);
 

src/Jenssegers/Mongodb/Relations/HasOneOrManyTrait.php

@@ -16,6 +16,7 @@
  * @package Jenssegers\Mongodb\Relations
  *
  * @property \Illuminate\Database\Eloquent\Builder $query
+ * @property string $localKey
  */
 trait HasOneOrManyTrait
 {
@@ -32,4 +33,48 @@ public function addConstraints()
             $this->query->whereNotNull($this->foreignKey);
         }
     }
+
+    /**
+     * @inheritdoc
+     */
+    public function addEagerConstraints(array $models)
+    {
+        // We'll grab the primary key name of the related models since it could be set to
+        // a non-standard name and not "id". We will then construct the constraint for
+        // our eagerly loading query so it returns the proper models from execution.
+        $key = $this->foreignKey;
+
+        $this->query->whereIn($key, $this->getEagerModelKeys($models));
+    }
+
+    /**
+     * Gather the keys from an array of related models.
+     *
+     * @param  array  $models
+     * @return array
+     */
+    protected function getEagerModelKeys(array $models)
+    {
+        $keys = [];
+
+        // First we need to gather all of the keys from the parent models so we know what
+        // to query for via the eager loading query. We will add them to an array then
+        // execute a "where in" statement to gather up all of those related records.
+        foreach ($models as $model) {
+            if (! is_null($value = $model->{$this->localKey})) {
+                $keys[] = new ObjectID($value);
+            }
+        }
+
+        // If there are no keys that were not null we will just return an array with null
+        // so this query wont fail plus returns zero results, which should be what the
+        // developer expects to happen in this situation. Otherwise we'll sort them.
+        if (count($keys) === 0) {
+            return [null];
+        }
+
+        sort($keys);
+
+        return array_values(array_unique($keys));
+    }
 }