feat: relationships allow conditional relation

Author: Ark4ne

readme.md

@@ -214,7 +214,9 @@ protected function toRelationships(Request $request): array
 {
     return [
         'avatar' => AvatarResource::relationship($this->avatar),
-        // as collection, with condition
+        // with conditional relationship
+        'administrator' => $this->when($request->user()->isAdmin(), UserResource::relationship(fn() => $this->administrator),
+        // as collection, with conditional value
         'comments' => CommentResource::relationship(fn() => $this->whenLoaded('comments'))->asCollection(),
         // with relationship (allow to include links and meta on relation)
         'posts' => PostResource::relationship(fn() => $this->posts)->withLinks(fn() => [

src/Resources/Concerns/Relationships.php

@@ -14,7 +14,7 @@ trait Relationships
      *
      * @param \Illuminate\Http\Request $request
      *
-     * @return array<string, Relationship>|iterable<Relationship>
+     * @return iterable<string, Relationship|\Illuminate\Http\Resources\PotentiallyMissing>
      *
      * ```
      * return [
@@ -39,8 +39,10 @@ protected function toRelationships(Request $request): iterable
     private function requestedRelationships(Request $request): array
     {
         $relations = [];
+        $relationships = $this->toRelationships($request);
+        $relationships = $this->filter($relationships);
 
-        foreach ($this->toRelationships($request) as $name => $relationship) {
+        foreach ($relationships as $name => $relationship) {
             $relationship->forRelation($name);
 
             $included = Includes::include($request, $name);

tests/app/Http/Resources/CommentResource.php

@@ -34,12 +34,12 @@ protected function toResourceMeta(Request $request): ?iterable
     protected function toRelationships(Request $request): iterable
     {
         return [
-            'user' => UserResource::relationship(fn() => $this->resource->user)
+            'user' => $this->when(true, UserResource::relationship(fn() => $this->resource->user)
                 ->withLinks(fn() => [
                     'self' => "https://api.example.com/comment/{$this->resource->id}/relationships/user",
                     'related' => "https://api.example.com/comment/{$this->resource->id}/user",
                 ])
-                ->whenIncluded(),
+                ->whenIncluded()),
             'post' => PostResource::relationship(fn() => $this->resource->post)
                 ->withLinks(fn() => [
                     'self' => "https://api.example.com/comment/{$this->resource->id}/relationships/post",