Simple News Reader

Rod Bailey Sunday 9 October 2016

Summary

This is an Android coding exercise. The app is called SimpleNewsReader and reads in a list of news items read from a well defined remote JSON file. It supports local caching of images and text and the ability to manually request a refresh of all the loaded data.

Screenshots

Running the app

You should be able to import the contents of this Github repository directly into Android Studio 2 or later:

• Select menu VCS then menu item Checkout from version control >
• Select Github.
• In the resulting dialog, enter a Github repository URL of https://github.com/replicant1/SimpleNewsReader.

To run the app you will need an AVD or real device that has at least Android API level 16 (4.1 JELLY BEAN) and internet connectivity.

Tests

There are a number of Espresso and JUnit unit tests provided.

Assumptions

Being a simple coding exercise, I have made a few simplifying assumpions:

• News items that don't have both a title and a description should not be displayed at all.
• The location from which the JSON is loaded won't change regularly - it is configured in assets/config.proerties
• The presence of the right arrow > in the requirements document at the right of each list item is an oversight. No functionaity for it is defined, so it should be omitted.

Technologies

The following libraries are used:

• Volley - by Google. Handles the mechanics of the HTTP request for downloading the JSON. Saves me having to deal with redirects etc. Also can do caching.
• GSON - by Google. Handles the parsing of the JSON data into data objects you provide.
• JUnit - for unit testing.
• UIL - Android Universal Image Loader. Asynchronously loads and caches the images referenced from the JSON.

Caching

UIL provides memory and disk caching upon request. We establish a memory cache of 200KB and a disk cache of 250KB. These figures are arbitrary selections. They are specified in /assets/config.properties.

Note that the feed at https://dl.dropboxusercontent.com/u/746330/facts.json supplies a header of max-age=0, meaning that it can't be cached, despite the fact that Volley has the capability to do so.

Potential improvements

• Only cache the thumbnails, not the original images at their full size.
• There are better ways to create the Views for each row in the list, using the ViewHolder pattern to enable recycling of Views that are off-screen.
• When an image is not found, don't keep trying to reload it in future. Somehow record that we have already tried to load it in this session, and failed.
• Cache the JSON text so that it is not reloaded on an orientation change. Images are not reloaded on an orientation change becuase the ImageLoader's cache persists across the change in orientation and the images returned are cacheable. But the JSON feed at the default location is marked as being not cacheable, meaning that Volley doesn't cache it, meaning that it is reloaded upon an orientation change.