Coding challenge for an iPhone application that allows a user to search Flickr for images.

Create the UI with a search bar at the top and a grid below it to display thumbnail images. The user should be able to enter text into the search bar and see a grid of images whose tags match the search string. The search string can be a single word (such as “porcupine”) or comma-separated words (such as “forest, bird”).

Fetch the list of images using this API from Flickr:

https://api.flickr.com/services/feeds/photos_public.gne?format=json&nojsoncallback=1&tags=porcupine

You’ll replace “porcupine” in that URL with the search word(s) typed by the user. This is a free public feed. No API key is required. You can learn more about this API here: The App Garden

Acceptance Criteria

• The search results should come from the API listed above (replace the word “porcupine” with the one typed by the user).
• The search results should be updated after each keystroke or change to the search string.
• When performing the search, show a progress indicator without blocking the UI.
• Tapping on an image should display an image detail view that contains the following details:
  • The image
  • Text element that displays the title
  • Text element that displays the description
  • Text element that displays the author
  • Text element that displays a formatted version of the published date
• Add at least one unit test that covers some portion of your code.