Accessing Data on a ManyToMany

Simple goal really: print all the droids assigned to a Starship. If you got comfortable with the OneToMany relation from Starship to its parts, then you're going to love this!

Open the template for the Starship show page: templates/starship/show.html.twig. I'll steal the h4 and p tag for arrived at, paste them below, and change the h4 to Droids. Clear out arrived at ... and break that line up.

We have a ship variable, which is a Starship object. And remember, it has a droids property and a getDroids() method. So: for droid in ship.droids. This calls the getDroids() method, and that returns a collection of Droid objects. So we can say {{ droid.name }}.

loop.last

I want commas, but not an extra comma at the end. Say: {% if not loop.last %}, {% endif %}. There are fancier ways to do this, but keep it simple for now.

If there aren't any droids, use an else tag and say No droids on board (clean up your own mess). Rude!

Droids on the Homepage

On the homepage, we want to show off the droids here too. Open up the template: templates/main/homepage.html.twig. Right after parts, add another div with Droids: {{ ship.droidNames ?: 'none' }}.

The Smart Method

We could use our loop.last comma thing again, but we've needed the droid names in two spots, so let's add a smart method for this in the Starship class. This could go anywhere, but I'll stick it at the bottom with the other droid methods. Create a public function getDroidNames(): string. To return a comma-separated string of droid names, check this out: return implode(', ', $this->droids->map(fn(Droid $droid) => $droid->getName())->toArray()).

Wow, that was a mouthful! Let's break it down:

1. $this->droids is our collection of Droid objects.
2. map() applies a function to each Droid in the collection.
3. fn(Droid $droid) => $droid->getName() is a hipster way to say "give me the name of each droid".
4. toArray() converts the collection to an array so it can be used with implode().

Finally, implode(', ', ...) takes that array of names and turns it into a comma-separated string.

Now that we've got a getDroidNames() method, we can say {{ ship.droidNames ?: 'none' }}.

We're done! Refresh... and enjoy the droid names on the homepage.

Next: let's use Foundry to set the ManyToMany relationship in the fixtures. Another place Foundry shines!