Many To Many Render

Coming soon...

Introducing Starships and Droids: The Perfect Duo

Alright, folks! We have a fantastic line-up of starships and their dedicated droids. Now, the million-dollar question is: how do we make this duo visible on our site? Let's consider a scenario: we've got a starship and we want to list all the droids assigned to it. Sounds tough? Not at all! It's actually a piece of cake, as simple as a OneToMany relationship!

The OneToMany Symphony

First things first, let's open our template /templates/starship/show.html.twig. No need to be picky about where exactly, but I'm going to snatch the H4 and the P tag for arrived at and then paste them below. Let's give arrived at a makeover and change it to droids. Clear out the arrived at down here and let's break that line up.

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This part is so simple it's almost laughable. We have a starship object, so for droid in ship.droids, we just call it droid. This calls the getDroids() method, which returns a collection of Droid objects. So, we can say things like {{ droid.name }}.

No Trailing Comma Drama

Let's jazz it up a bit. We want commas, but not that pesky trailing comma. Here's a neat trick for you: I'll say {% if not loop.last %}, {% endif %}. I know, I know, you're thinking I could show you a more sophisticated way to do this. And you're right! But let's stick with the basics for now.

The Polite Else Tag

Here's where it gets fun. If there aren't any droids to loop over, we can use an else tag and say No droids on board (clean up your own mess). Sounds a bit snarky? It's the hard truth, my friends! This works because droid is a Droid object. We're simply leveraging our ManyToMany relationship. It's as simple as that.

Droids on the Homepage

Now that we're flexing our coding muscles, let's show off a bit on the homepage. I want to list all the droid names related to the starship. It's pretty similar to what we did earlier, but with a little twist. Open up the template for this at /templates/main/homepage.html.twig. Right after parts, let's dive in. I'm going to add another div and say Droids: {{ ship.droidNames ?: 'none' }}.

The Smart Method

Sure, we could use our loop thing and loop.last comma thing, but why not show off a bit? We've needed the droid names in two spots, so let's add a new smart method in the Starship class. This could go anywhere, but let's stick it at the bottom of the class where we have our droid methods already. Let's create a public function getDroidNames(): string. Now, we'll return the string, the comma-separated string using return implode(', ', $this->droids->map(fn(Droid $droid) => $droid->getName())->toArray());.

Wrapping it Up

Now we've got our getDroidNames() method and it's going to be a breeze to use it on our homepage. We just say {{ ship.droidNames ?: 'none' }} and voila, we're done! You'll see our droids listed and if there are no droids, it'll just say none.

So, this wasn't some flashy tutorial on ManyToMany relationships, but we did add a neat smart method to our entity. In the next session, let's explore how we can join across ManyToMany relationships. Till then, keep coding and having fun!