Homework 2

Due: Wednesday February 2, 11pm.

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Assignment

We are going to build a simple app that interrogates a weather API, and reports the weather conditions for the location.

The Weather API

To get the weather, you need to issue an HTTP GET call to this URL:

http://luca-teaching.appspot.com/weather/default/get_weather

The response looks like this.

It can be a server error (500).

It can be an application error:

 {"response": {"result": "error"}}

Or else, it can be a proper weather response, which looks similar to this:

{"response": {"conditions": {"wind_gust_mph": 0, "temp_f": 52.299999999999997, "observation_location": {"city": "High St, Santa Cruz", "full": "High St, Santa Cruz, California", "elevation": "141 ft", "country": "US", "longitude": "-122.034447", "state": "California", "country_iso3166": "US", "latitude": "36.977425"}, "temp_c": 11.300000000000001, "relative_humidity": "90%", "weather": "Clear", "dewpoint_c": 10, "windchill_c": "NA", "pressure_mb": "1025", "windchill_f": "NA", "dewpoint_f": 50, "wind_mph": 0.0}, "result": "ok"}}

(Note the "result": "ok" : this is what tells you that this response is valid).

What you have to build

You have to build an application consisting of one activity.

When you open the activity, there is a button that says: "Get Weather Conditions".

When you click it, it has to do the server call, get the weather conditions, and display them.

You need to display at least

• something from location (city name and elevation, at least)
• temperature
  • relative humidity
  • wind speed (average and gusts)
  • weather (the string tagged by "weather")

You can display more if you wish.

If an error occurs, you have to advise the users with some kind of error string, and you have to let them try again to get the weather.

That's it. A simple assignment on doing http calls.

Please:

• Write your code clearly.
• Use the Retrofit library explained in class.
• Make sure the info is presented readably, does not disappear if the phone/tablet is rotated, and is scrollable so can be read on small screens.

Testing your code

You might find useful these other URLs:

• http://luca-teaching.appspot.com/weather/default/get_500 always returns error 500
• http://luca-teaching.appspot.com/weather/default/get_no_weather always return the Json application error
• http://luca-teaching.appspot.com/weather/default/get_good_weather always returns the weather with no errors (except if errors really happen).

Do not use them in the homework submission, but you may find them useful in testing. After the submission deadline, these functions will work like the standard get_weather.