add UIImage from a URL to a promotion screen in a rubymotion app

Question

I've had a bit of trouble following the docs to add an image to a promotion screen. I am pulling a post object from a server which contains an image url. I would like to show the post body as well as an image if one exists in the post. My most recent attempt yields the error

*** Terminating app due to uncaught exception 'NSInvalidArgumentException', reason: '-[__NSCFString bytes]: unrecognized selector sent to instance 0xa813810'

when running this code:

class PostScreen < BaseScreen
  attr_accessor :post

  def on_load
    self.title = "#{self.post['person']['name']}'s post"
  end

  def will_appear
    super
    add UILabel.new, {
      text: self.post['body'],
      font: UIFont.systemFontOfSize(16),
      left: 20,
      top: 100,
      width: 280,
      height: 300,
      text_alignment: NSTextAlignmentCenter,
      lineBreakMode: UILineBreakModeWordWrap,
      numberOfLines: 0
    }
    if self.post['images'].length > 0
      add UIImageView.new, { 
        image: UIImage.alloc.initWithData(self.post['images'][0]['image_uploader']['medium_square']['url'])
      }
    end
  end
end

I'm quite new to rubymotion (obviously) so please ask if you need more info to answer the question. I'm assuming this is pretty straightforward but I have to step away for the evening so I thought StackOverflow could take a crack at it.

Thanks!

-------- Update -------------

After some digging, I believe this is closer to correct:

if self.post['images'].length > 0
  url = self.post['images'][0]['image_uploader']['medium_square']['url']
  v = UIImageView.new
  v.setImageWithURL("url")
  add v
end

I am using the cocoapod SDWebImage which I believe gives me that setImageWithURL method. When I run the app, v.image is null. When I run that same serious of commands in the console, an image is successfully added to the UIImageView.

Answer 1

From the rubymotion cookbook (https://github.com/IconoclastLabs/rubymotion_cookbook/blob/master/ch_2/17_imageview/app/root_controller.rb) I was able to get this working

if self.post['images'].length > 0
  url = self.post['images'][0]['image_uploader']['medium_square']['url']

  image_view = UIImageView.alloc.initWithFrame(self.view.bounds)
  image_view.contentMode = UIViewContentModeScaleAspectFit
  image_view.center = self.view.center
  image_view.setImageWithURL(url)
  add image_view
end

I'm sure there are a lot of ways to accomplish my goal and maybe some better. I'd still love for someone to answer this question better than me and I will gladly give you the check mark!

Answer 2

I think you should fetch the data first and then assign that data to your image view. And for that I would recommend using AFMotion

@image_view = add UIImageView.new
@image_view.url = self.post['images'][0]['image_uploader']['medium_square']['url']

Just please don't use BubbleWrap's HTTP library, it's being deprecated in favor of promoting AFNetworking (which AFMotion wraps to make it more idiomatic).