Flash message being rendered on exception page

Question

I have a weird issue. We have an image validator that prevents images smaller than a certain size being uploaded. If the image is too small then it directs the user to the /upload page with a flash error message.

It was working nicely until I made some major changes to the app; Major refactor, including moving code into modules, upgrading to rails 3.2.13 and moving from R Magick to Mini Magick. Quite a few things, I didn't change anything to do with the validator.

Now for some reason it doesn't redirect to the /upload page anymore with the flash message. Instead, in development, it shows the error message on the rails exception page titled "ActiveRecord::RecordInvalid in UploadController#create". And in production, on Heroku, it responds with the 422 page, "The change you wanted was rejected".

Any ideas?

Create action in the controller

  def create
    @item = Item.create!(params[:item])
    if @item.save
      redirect_to crop_url(item_id: @item.id)
    else
      error_msg = @item.errors[:base]
      redirect_to upload_url, flash: { errors: error_msg }
    end
  end

Validate method in the upload_process module

def validate_minimum_image_size
  geometry = cover.geometry
  if (! geometry.nil?)
    width = geometry[0]
    height = geometry[1]
  end
  unless (width >= 540 && height >= 540)
    errors.add :base, "Oops! Your image is too small... Dimensions must be at least 540x540 pixels!"
  end
end

Error message in the view (HAML)

.error
  .pink
    - if flash.present?
      - if flash[:errors].present?
        - flash[:errors].each do |err|
          = err

Answer 1

You should have:

@item = Item.new(params[:item])

instead of:

@item = Item.create!(params[:item])

Error occurred because you were calling create! - this method raises error if the validation fails.