Symfony 4 Forms: Build, Render & Conquer!


A bit of Security Cleanup

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There's one last piece of business that we need to clean up. In ArticleAdminController, we created this endpoint... but we didn't add any security on it! It's open entirely to the world: there's no @IsGranted annotation above the method or above the class.

Securing the new Endpoint

Now... this might be ok - this endpoint just returns some boring, non-sensitive HTML anyways. But, let's be cautious.

The tricky thing is that this endpoint is used on both the new and edit form pages. On the new page, we require you to have ROLE_ADMIN_ARTICLE. But on the edit page, we use a special voter that gives you access if you have ROLE_ADMIN_ARTICLE or if you are the author of the article.

So, hmm - our endpoint needs to be available to anyone that has ROLE_ADMIN_ARTICLE or is the author of at least one article. A little odd, but we can make that happen!

The proper way to solve this is to create a new voter and call @IsGranted() with a new attribute we invent, like ADMIN_ARTICLE_FORM. The voter would handle that attribute and have all the logic inside.

But... because we only need to use this security logic on this one endpoint, and because I'm feeling lazy, let's instead put the logic right in the controller. We can always move it to a voter later if we need to re-use it.

First, add @IsGranted("ROLE_USER") to at least make sure the user is logged in. Then, inside the method, if not $this->isGranted('ROLE_ADMIN_ARTICLE') and $this->getUser()->getArticles() === 0, then we should not have access. Wait, but the ->getArticles() method is not auto-completing for me.

... lines 1 - 14
class ArticleAdminController extends BaseController
... lines 17 - 69
... line 71
* @IsGranted("ROLE_USER")
public function getSpecificLocationSelect(Request $request)
// a custom security check
if (!$this->isGranted('ROLE_ADMIN_ARTICLE') && $this->getUser()->getArticles()->isEmpty()) {
... lines 78 - 92
... lines 94 - 105

Oh, I know why! Go to the top of this class and change the base class from extends AbstractController to extends BaseController.

... lines 1 - 14
class ArticleAdminController extends BaseController
... lines 16 - 107

Reminder: BaseController is a controller that we created. It extends AbstractController but it adds a return type to getUser() with our User class so we get auto-completion.

Back down in our method, we can say $this->getUser()->getArticles()->isEmpty(), which is a method on Doctrine's Collection object. So, if we don't have ROLE_ADMIN_ARTICLE and we are not the author of any articles, throw $this->createAccessDeniedException().

... lines 1 - 73
public function getSpecificLocationSelect(Request $request)
... line 76
if (!$this->isGranted('ROLE_ADMIN_ARTICLE') && $this->getUser()->getArticles()->isEmpty()) {
throw $this->createAccessDeniedException();
... lines 80 - 92
... lines 94 - 107

Done! And just to make sure I didn't completely break things, if I change the location to "Near a star"... yea! It still loads.


What really made adding this security easy was being able to call $this->getUser()->getArticles(). The problem is that if this user is the author of 200 articles, then this will query for 200 rows of articles and hydrate those into 200 full objects, just to figure out that, yes, we are the author of at least one article. All we really need is a quick count query of the articles.

Fortunately, we can tell isEmpty() to do that! Open User and look for that articles property. At the end of the @OneToMany annotation, add fetch="EXTRA_LAZY". We talked about this option in our Doctrine relations tutorial. With this set, if we simply try to count the articles - which is what isEmpty() does - then Doctrine will make a quick COUNT query instead of fetching all the data. Nice!

... lines 1 - 19
class User implements UserInterface
... lines 22 - 63
* @ORM\OneToMany(targetEntity="App\Entity\Article", mappedBy="author", fetch="EXTRA_LAZY")
private $articles;
... lines 68 - 268

Using the @method in BaseController

Ok, one more thing - and it's also unrelated to forms. Open BaseController. By extending AbstractController, this class gives us all the great shortcut method we love but it also overrides getUser() so that our editor knows that this method will return our specific User class.

After we did this, a wonderful SymfonyCasts user pointed out that the getUser() method on the parent class is marked as final with @final. When something is final it means that we are not allowed to override it. Symfony could enforce this by changing the method to be final protected function getUser(). Then, we would get an error! But, Symfony often uses the softer @final comment, which is just documentation, either to prevent breaking backward compatibility or because it's harder for Symfony to unit test code that has final methods.

Anyways, the method is intended to be final, which means that we're not supposed to override it. So, delete the method in our class. There's another nice solution anyways: above the class add @method User getUser().

... lines 1 - 7
* @method User getUser()
abstract class BaseController extends AbstractController
... lines 12 - 13

That's it! That does the exact same thing: it hints to our IDE that the getUser() method returns our User object. Back in ArticleAdminController, if we delete getArticles() and re-type... yep! It works!

Phew! Amazing job people! That was a huge topic to get through. Seriously, congrats!

The Symfony form system is both massively powerful and, in some places, quite complex. It has the power to make you incredibly productive or just as unproductive if you use it in the wrong place or the wrong ways. So, be smart: and follow these two rules.

One: if your form looks quite different than your entity, either remove the data_class option and use the associative array the form gives you to do your work or bind your form to a model class. Two: if your form has a complex frontend with a lot of AJAX and updating, it might be easier - and a better user experience - if you skip the form and write everything with JavaScript. Use this tool in the right places, and you'll be happy.

Let me know what you guys are building! And, as always, if you have any questions, ask us down in the comments.

Alright friends, see ya next time.

Leave a comment!

  • 2019-05-16 Diego Aguiar

    You are welcome! :)

  • 2019-05-16 aziz

    Good and nice topic i never seen it before,since 2014 i used symfony.
    Thanks a lot.

  • 2019-01-08 Diego Aguiar

    Hey CharlES

    > the problem I see that a user may have ROLE_ADMIN_ARTICLE and may not have written any article, and it's the first time
    There should not be a problem because if the User has the ROLE_ADMIN_ARTICLE role, then the IF statement is valid because we check for that specific role OR if he's the author of at least one article. I hope it makes any sense to you.


  • 2019-01-08 CharlES

    the problem I see that a user may have ROLE_ADMIN_ARTICLE and may not have written any article, and it's the first time, or have I missed something? By the way, thank you for the isEmpty() function, didn't know the power of collections until I was given to look for that function, lol => https://www.doctrine-projec...

  • 2019-01-01 mouerr

    happy to hear that weaverryan thank you very much

  • 2018-12-31 weaverryan

    Hey Matt!

    Yea, really think that we should do those tutorials for Symfony 4 as well - I LOVED those tutorials. The problem right now (a good problem) is that there's just so much good stuff to cover. We'll start a phpspec tutorial in about a week (not too big), then I'm not entirely sure - we'll be making plans in about a week. But we're targeting API Platform in 2019, Messenger, probably more JavaScript stuff, design patterns stuff, maybe this idea you had, and more. We're going to go as fast as we can :).


  • 2018-12-27 Matt

    Hi Ryan Weaver!

    I Symfony 3 series there where two tutorials "Journey to the Center of Symfony" namely "HttpKernel Request-Response" and "The Dependency Injection Container". Those were the huge ones - the real heart of Symfony. Do you consider analogous tutorials in Symfony 4 series?

    P.S. What's next in your timetable after Forms?