validation_max bug in inputs/base/validations in v2.0.0.rc3

[mhenrixon]

I have this numericality validation in my model and now it seems like formtastic chokes on it somehow when trying to follow the Proc.

validates_numericality_of :min_sphere, 
  less_than: Proc.new { |frame| frame.max_sphere }, 
  greater_than_or_equal_to: -60, 
  only_integer: false 

validates_numericality_of :max_sphere,
  less_than_or_equal_to: 60,
  greater_than: Proc.new { |frame| frame.min_sphere },
  only_integer: false 

Error message:

undefined method `-' for #<Proc:0x000001049e6c68>
formtastic (2.0.0.rc3) lib/formtastic/inputs/base/validations.rb:88:in `validation_max'

View code:

=f.input :min_sphere

[justinfrench]

If you'd like to try to patch it, I would take a look at Formtastic::Inputs::Base::Validations#validation_max (and min), and take a look at this line:

return (validation.options[:less_than] - 1) if validation.options[:less_than]

This line is assuming that :less_than is a number, not a Proc. The code needs to be changed to something like this, which detects and calls the Proc.

if validation.options[:less_than]
  return (...) if validation.options[:less_than].kind_of?(Proc)
  return (validation.options[:less_than] - 1)
end

The (...) obviously needs filling in :)

I was about to suggest another work-around may be to try :less_than_or_equal_to, but I think this would avoid the - 1 error, but still result in a Proc rather than a useful number in the min and max.

If you wish to bypass this logic completely until it's sorted out, a custom version of NumberInput in app/inputs/number_input.rb should help:

 class NumberInput < Formtastic::Inputs::NumberInput
   def step_option
     return options[:step] if options.key?(:step)
     1
   end

   def min_option
     return options[:min] if options.key?(:min)
   end

   def max_option
     return options[:max] if options.key?(:max)
   end
 end

Basically, it will only use min/max/step from the options, not from validations, etc.

[mhenrixon]

Spot on suggesting me to patch it. I am a ruby n00b still but thanks to your detailed description of the problem I think I'll manage to solve this one. Give me a day or so to do this and I'll send you a pull request.

If I wanted to write tests for this I suppose that I'd add this for both range_input_specs, number_input_specs?

[justinfrench]

Yes, they're the right places to add coverage, but it could be a lot of data to set-up, so a quick hack around with bundle open formtastic within your app might ensure we're on the right path to start with.

[mhenrixon]

Ok so I fixed the issue but I have to spend some time with the specs before I can add that. A LOT!! of setting up done in the spec_helper :)

[justinfrench]

@mhenrixon, how's the specs going? Would love to get a new RC out this week!

[mhenrixon]

Sorry about that, I completely forgot about it. Will try and create something tonight.