Casting a null value to a collection should return an empty collection

[hackel]

When casting an Eloquent model attribute to a 'collection', if the value is currently null, the cast does not take place, and null is returned.

To avoid having to litter the code with existence tests for that attribute, and also be consistent with relationships, I propose an empty collection be returned instead.

On the saving side, there could also be logic to save an empty collection as null, but this is not critical.

Unfortunately this would be a breaking change. Any existence check e.g. if ($model->collection) would need to be changed to if ($model->collection->isEmpty()), but in many of those cases, I suspect the check would no longer be necessary.

[Miguel-Serejo]

null and empty collection can legitimately mean different things.

For example, a null value in the database can indicate that a user hasn't selected any preferences yet, while an empty collection can indicate that a user has specifically stated they have no preferences.

If in your app null and empty collection mean the same thing, I suggest making the default value of the column an empty collection rather than null.

[mfn]

I'm with @36864 : null and empty collection can (and in many of my cases do) carry different semantics => 👎 on the idea.

[donnysim]

You can make a getter if you want an empty collection even if the value is null, would make more sense than breaking the behavior that is expected.

[andrey-helldar]

@hackel, if I understand your problem correctly, the changes proposed in laravel/framework#30958 will make it easy to solve.