Certainly! Here’s a clear answer incorporating explanation and code examples as requested:
You're absolutely correct in your assessment: the Laracasts/Laravel documentation is a bit ambiguous and can mislead when it comes to using resource collections, especially with JSON:API formatting and how the included relationship data is handled.
What's Actually Happening?
1. This:
return PostResource::collection(Post::all());
Returns an anonymous resource collection (Illuminate\Http\Resources\Json\JsonResource::collection), which by default will handle JSON:API features such as the included key when dealing with relationships—assuming your PostResource is set up to provide it.
2. This:
return Post::all()->toResourceCollection();
Will (in the absence of a custom PostCollection) fallback to Illuminate\Http\Resources\Json\ResourceCollection, which doesn’t guarantee behavior parity with anonymous collections, particularly around JSON:API's included key and data structure unless further configured. This is important for those wanting a strict JSON:API compliant output, especially for handling relationships.
If you want to achieve identical behavior to the first usage, you do need to specify the resource class as a parameter:
3. Thus, you want:
return Post::all()->toResourceCollection(PostResource::class);
Which is equivalent to the first example, since it wraps each item in the specified resource and uses the correct logic for serialization.
Why Is This Important?
The difference can be subtle, but for a strict JSON:API implementation and third-party tooling (including Ember, Orbit, or frontend datastores), having the included data is essential for efficient resource linkage and to avoid extra network calls.
If you only use toResourceCollection() without $resourceClass, Laravel will try to look for PostCollection, which—unless you specifically configure—won't include JSON:API behaviors for "included" data.
In Summary
To ensure your API output behaves consistently and is fully JSON:API compliant (with relationships and included data handled as you expect):
Always explicitly specify the resource class when using toResourceCollection:
return PostResource::collection(Post::all());
// is equivalent to:
return Post::all()->toResourceCollection(PostResource::class);
Reference (from Laravel's /vendor/laravel/framework/src/Illuminate/Database/Eloquent/Collection.php):
public function toResourceCollection(?string $resourceClass = null): ResourceCollection
{
if ($resourceClass === null) {
return $this->guessResourceCollection();
}
return $resourceClass::collection($this);
}
Conclusion
So yes, the documentation can be misleading if you’re targeting strict JSON:API support. Always pass your resource class to toResourceCollection() (or use the static Resource::collection()), unless you've set up a custom collection that properly supports included (which is rare). This will guarantee consistent output.
Your observation is correct: pass the resource class as a parameter for parity, especially with JSON:API formatting!