Collection Criteria for Custom Relation Queries

Welcome back to the Symfony world, you'll be amazed with all the new features!

For anyone else reading (and future myself): here's the lesson where Ryan talks about it: https://symfonycasts.com/screencast/doctrine-queries/criteria

Hey Andrey,

Yep, exactly! :) This feature might be really interesting and powerful in some cases.

Cheers!

Hey Hanane,

Definitely the QuestionBuilder, it's more flexible and I'd recommend you to always start with it, and in some cases when it doesn't work for you - you may fallback to Criteria. So, when use one or another - it depends on specific case, but as you already guessed yourself - Criteria mostly used in entities to customize (filter) the collection, because as you said you can't use QueryBuilder in entities - it's not recommended as entities are simple data and injecting any services into it is a bad practice.

I hope this helps!

Cheers!

In what classes also we should not inject services?
Honestly, I was a little bit confused when Ryan said that we can't use repository in an entity.
And I was going to ask you why, because I thought we can autowire services in ANY class inside src folder.

But then I saw your comment where you say that it's just a bad practice.

Hey!

Well, it depends. on your application, but mostly you have controllers, entities and... services in your app. Actually, almost everything in your app is a service, and you can inject services into other services. Unfortunately, data objects like your entities are not services, and so it's not correct to inject other services into entities. The idea is that you operate data in your controllers/services. So, if you think about it - I bet you will realise that you don't need to inject anything in entities, because most probably you're using those data in controllers, where you can inject a repository class and execute any query you want to fetch the data you need. So, controllers is the place where you get some data and pass them to template where those data will be rendered. I.e. in your project you operate data using controllers and services, something like this.

I hope this helps!

Cheers!

I kind of understand you, but I have a question.

As Ryan always say WORK = SERVICE.
What if we need some work, when we try to get some entity field?

For example, in Question entity we have getVotesString() method, which contains logic for processing votes field (adds + or - sign).
But what if I need more complex logic to process that field and return in some other format. Could it require some WORK?

Hey Phy,

Great!

If you need to do some work - create a service for this. If we're talking about entities - they already have repositories, so you can pass some simple logic there. Otherwise, create a standalone service and use, i.e. pass an entity to that service that need to do some work with their data. The service will do the complex work, e.g. any heavy calculations you need, and then set the final value to the entity.

But if we're talking about some simple actions, like incrementing the value that does not need any third-party services - you can do this in the entity, i.e. create a special method for this, e.g.:

public function incrementVotes()
{
    $this->votes++
}

So, it depends on the complexity of the business logic you need. I hope this clarify things for you!

Cheers!

Cool, thank you, Victor!