Empty values can't be coerced

[SleeplessByte]

When a form is submitted and the value is empty (but present as key because it was in the form).

Coercing

'' Can't be coerced into Date

[jodosha]

@SleeplessByte Thanks for reporting this. We'll start reworking Lotus::Model low level mechanisms next week. So we'll take in account this problem.

For the time being, you can avoid to hit this problem, by validating your data.

[SleeplessByte]

I actually unset empty values before I pass them to the repository, because the skip? if blank? only skips it for validation. Not for creation.

[jodosha]

@SleeplessByte I'm confused. 😢

You should invoke methods on the repository, only if you're sure they are valid. This is a framework design. In pseudo code:

if my_data_is_valid?
  MyRepository.create(my_entity_instance)
end

As opposite of other libraries like ActiveRecord, where the control happens inside the repository role:

MyModel.create(my_data) # check data inside.

---

Do you have some code to share with us? It would help to understand better your use case 😄 Thanks!

[SleeplessByte]

@jodosha Sorry about the confusion.

Adding validations to the action#params actually solved this because it filters out empty params. This however is not clear from the documentation. After I updated my gems I think entity.valid? / action#params.valid? both ignored the empty values correctly.

[SleeplessByte]

Woops. The bug is still there off course for no validations.

[jodosha]

Woops. The bug is still there off course for no validations.

Which version do you used before, and which one after the upgrade?

[SleeplessByte]

0.5.0 to 0.6.x + lotusrb edge.

I have not encountered the error since yesterday.

[jodosha]

@SleeplessByte Thank you. I suspect this could be related to hanami/validations#82 /cc @hlegius

[hlegius]

@SleeplessByte if I got you correctly, you're trying to persist params directly thought your Entity, instead of use the validated params (a.k.a Lotus Validation output (with .to_h method) after you've checked if its valid (.valid?, .invalid?). This way, you'll get this coerce issue.

About blank values, since hanami/validations#82, you can have blank param's keys for both size and type validation' attributes.

If you still experiencing some unexpected behaviour on this, please, paste here some of your implementation. I'd be glad to help you!

[SleeplessByte]

@jodosha It was, that's why switching to edge resolved it.

@hlegius I was and I was not. I realised quickly that I had to do params.valid? to validate parameters. Right now I just have Lotus::Validations in both model and params. In the documentation .to_h is not mentioned, and it should if that is the way to go.

Right now the flow is something along the lines of:

params do
   param :foo do
       param :bar, baz: :validation
       ...
   end
end

def call( params )
  ...
  if params.valid?
     @my_model = MyModel.new( params[ :foo ] )
     @my_model = MyModelRepository.create( @my_model ) or raise SomeException
     ...
  end
  ...
end

And this works.

I had one problem using presence: false (default) and format: but that's resolved as well.

Long story short (\cc @jodosha ): Personally, I don't think it is clear enough that

• one must validate params and not the model
• there is no safe handling of faulty values for model params
• using params after validation will sanitize empty values
• which validations are available by default, and which are after skip? (easy to check in the source, but still)