[10.x] Allow utilising withTrashed(), withoutTrashed() and onlyTrashed() on MorphTo relationship even without SoftDeletes Model

[crynobone]

This would be useful in some 3rd party packages as this has become an issue where it's not possible to define the relationship such as $this->morphTo()->withTrashed() unless all relationship uses SoftDeletes trait:

• Eager loading target relationship on ActionEvent for a non soft-deleted model throws an exception nova-issues#5754
• Subject should only return soft deleted models if that model uses SoftDeletes spatie/laravel-activitylog#456

Test without and with code changes

[taylorotwell]

@crynobone you mean all of the morphable models have to be soft deletable?

[crynobone]

Before this changes if we want to use morphTo()->withTrashed() and then query using Action::with('target') all morphable model need to use soft deletes or it would throw an exception (similar to failed test).

This work well for application models but if a package provides morphable relationship and doesn't fully know which model would use it they would faced this issue.

[utsavsomaiya]

https://laravel-auditing.com/guide/community/troubleshooting.html#attribute-accessors-and-modifiers-are-not-applied-to-softdeleted-models

[matiaslauriti]

Why would a model do nothing when withTrashed etc is called if it does not have the SoftDeletes? Is like saying "I want to eat vegetables and rice, but I only have a rice, I still expect to remove the lid and see vegetables in there"... the package should check or do something related to those non-existing methods, else withTrashed should return the same query builder but without changing anything, and I would say that is not a good behaviour because then, you would need to know that it does not implement SoftDeletes so it would do nothing at all...

I may still be confused or something similar, but still... it is not good at all to call a method and do nothing... it should throw an error if it is not implemented but not implement an "empty" method, right?

[crynobone]

Why would a model do nothing when withTrashed etc is called if it does not have the SoftDeletes?

This has already been done on Route::withTrashed() and the same argument can be applied.

[mreduar]

This is great, thank you very much, I have been dealing with this problem for a while now.