Persist Join Entity

Coming soon...

Fixing the Error Caused by Refactoring

Alrighty folks, our Symfony journey continues! After we've dutifully refactored our many-to-many relationship to include a join entity called StarshipDroid, we're going to reload our fixtures. Hold onto your hats, here comes an error! We're greeted with an Undefined property: App\Entity\Starship::$droids message. This error is being spat out from StarshipLine205. The culprit? It's our getDroids() method.

You might be wondering, "Why is that?" Well, let me shed some light on it. Think of our Starship as a spaceship carrier that's trying to figure out how many droids it has. When we're linking the droids to the Starship in the fixtures, StarshipArrow getDroids() gets called behind the scenes. It's like a roll call for droids. But, we've still got a reference to a phantom property which no longer exists, so naturally, it's going to trip up. The quick fix? We're going to comment it out and huzzah! The fixtures are back in action.

Creating Objects by Hand

Now, to really drive home what changed here and what's causing our problem, I'm going to create a couple of objects by hand. It's like digital origami. We'll start by declaring ship equals StarshipVector. We could use crate1, but let's mix things up and grab a random one. And just to keep things crystal clear, we're going to use the underscore real trick so we have the real McCoy, not some shadowy proxy. We'll rinse and repeat to grab a droid with droid equals droidFactory, grabbing a random one again and calling real() on that.

Highlighting the Key Change

Here's where the plot thickens. Previously, we could use shipArrow addDroidDroid with no issues. Now, it's as useful as a chocolate teapot. Why? Because it's referencing the obsolete droids property. It's now called StarshipDroids, and as you might've guessed, it's just a join entity. This means we need to get a little more hands-on. It's like swapping out an auto-pilot for a manual control stick. We'll ditch shipArrow addDroid and instead declare StarshipDroid equals new StarshipDroid, then StarshipDroidArrowSetDroid, not ship but droid. Next, we'll set StarshipDroidArrowSetStarship to ship. We're manually creating this entity and setting up those many-to-one relationships. And finally, since we're assembling these by hand, we need to persist and flush them using managerArrow persist StarshipDroid, and managerArrow flush.

Sure, it's a bit of work, but think of it as a simple, somewhat dull, but necessary pit stop on our Symfony road trip. Give the fixtures a spin and let's peek at the database with doctrine query SQL, select star from StarshipDroid. We're selecting from that join table and voila! One entry for one Starship, and one droid. So far, so good. Let's refresh the homepage. Oh dear, another error! It's [Semantical Error] line 0, col 55 near 'droids WHERE': Error: Class App\Entity\Starship has no association named droids. Looks like we've got a query issue on our hands.

Fixing the Query Issue

Time to roll up our sleeves and dive into src/repository/StarshipRepository. Our join here is having a bit of a meltdown. We're joining at s.droids, but droids property has left the building. We need to join on StarshipDroids. So let's change s.droids to s.starship. StarshipDroids. And for clarity, let's call it StarshipDroid, because that's what it really is. I like to keep things singular, so we'll stick with StarshipDroid and simply count them instead of the nonexistent droids.

With that sorted, we'll refresh the homepage and... we've got another error. It's Warning: Undefined property: App\Entity\Starship::$droids. This is coming from our ship.droidNames in the homepage template. We know that when we call ship.droidNames, it's calling StarshipArrowGetDroidNames and we're still referencing the ghost of the droids property.

Making Magic Happen

Now, let's sprinkle some Symfony magic dust. We'll fix this in a way where we only have to make changes in one file, and the rest of our application will just start working. Now that's what I call coding magic!