Class: ShortRails::ShortUrlsController

Inherits:
ApplicationController show all
Defined in:
app/controllers/short_rails/short_urls_controller.rb

Instance Method Summary collapse

Instance Method Details

#create ⇒ Object

POST ‘/’ create short URL



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# File 'app/controllers/short_rails/short_urls_controller.rb', line 27

def create
  begin
    short = SecureRandom.base64(6).tr("+/=", "xyz").downcase
  end while ShortUrl.where(short: short).exists?

  url_params = params.except(:action, :controller, :base_url, :base_url_short_param).permit!.to_hash
  short_url = ShortUrl.new(short: short, url: params[:base_url], params: url_params, url_short_param: params[:base_url_short_param])
  if short_url.save
    # return short id
    render plain: short
  else
    head :bad_request
  end
end

#parameters ⇒ Object

GET ‘:id/params’ get parameters for full URL



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# File 'app/controllers/short_rails/short_urls_controller.rb', line 44

def parameters
  short_url = ShortUrl.find_by_short(params[:short])
  if short_url.nil?
    head :not_found
    return
  end

  render json: short_url.params
end

#qrcode ⇒ Object

GET ‘:id/qrcode’ get QR code containing this short URL



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# File 'app/controllers/short_rails/short_urls_controller.rb', line 56

def qrcode
  require 'rqrcode'

  if ShortUrl.find_by_short(params[:short]).nil?
    render plain: "ERROR: Could not generate QR code", status: :not_found
    return
  end

  width = params[:width].to_i
  height = params[:height].to_i
  if width > 2048 || height > 2048
    render plain: "ERROR: Requested image size is too large", status: :bad_request
    return
  end

  # create QR code with minimal version
  qr = nil
  version = 3
  while qr.nil? && version < 40
    begin
      qr = RQRCode::QRCode.new(short_url_url, size: version, level: :h)
    rescue
      # current version has not enough capacity, try next version
      version += 1
    end
  end
  if qr.nil?
    render plain: "ERROR: Could not generate QR code", status: :bad_request
    return
  end

  qr_size = 17 + 4 * version
  # min size is QR code pixels with a border of 4 QR code pixels
  border_modules = 4
  min_size = (qr_size + border_modules * 2)
  if params[:width].nil? && params[:height].nil?
    # default size with 3 image pixels per QR code pixel
    img_size = 3 * min_size
    width = img_size
    height = img_size
  else
    # clamp to min default size
    width = [width, min_size].max
    height = [height, min_size].max
    img_size = [width, height].min
  end

  qr_image = qr.as_png(
    size: img_size,
    border_modules: border_modules
  )

  if width > img_size || height > img_size
    # calculate image size to fit scaled QR code to requested size
    size = [width, height].min
    img_size = (size / img_size) * img_size
    qr_image = qr_image.resize(img_size, img_size)

    if width > img_size || height > img_size
      # center QR code in image of requested size
      image = ::ChunkyPNG::Image.new(width, height, ::ChunkyPNG::Color::WHITE)
      offset_x = (width - img_size) / 2
      offset_y = (height - img_size) / 2
      qr_image = image.replace(qr_image, offset_x, offset_y)
    end
  end

  send_data qr_image.to_s, type: 'image/png', disposition: 'inline', filename: "#{params[:short]}.png"
end

#show ⇒ Object

GET ‘:id’ redirect to base URL



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# File 'app/controllers/short_rails/short_urls_controller.rb', line 7

def show
  short_url = ShortUrl.find_by_short(params[:short])
  if short_url.nil?
    head :not_found
    return
  end

  if short_url.url_short_param.nil?
    # redirect to full URL
    query_params = short_url.params
  else
    # redirect to base URL with short param
    query_params = {short_url.url_short_param => short_url.short}
  end

  redirect_to "#{short_url.url}?#{query_params.to_query}"
end