TripPlanner

We are going on a trip later today, and we want to create an application that will help us pack our bags based on the weather at our destination.

As a user I want to:

• Tell the app where I'm going
  • e.g. 'London, UK', 'Honolulu, HI', 'Dalton, GA'
• Tell the app how many days I'll be gone for.
• Have the app tell me the overall forecast for those days.
  • e.g. "January 18th will be sunny, with a low of 45 and a high of 72."
• Have the app tell me what clothing to pack for the trip, both based on temperature as well as weather conditions
  • e.g. "You should bring shorts, a windbreaker, and a visor."
• Have the app write to a file so I can retrieve the results later.

OpenWeatherMap API

We're going to get daily weather data for a location. Suppose the user has already supplied us with city and days.

  units = "imperial" # you can change this to metric if you prefer
  options = "daily?q=#{CGI::escape(city)}&mode=json&units=#{units}&cnt=#{days}"
  url = "http://api.openweathermap.org/data/2.5/forecast/#{options}"

Remember we need to escape the city since spaces and certain characters in a url can cause errors.

Part I - TripPlanner

Let's create the class that will be our main object. Once we're ready to start the program, we'll simply run the following code, and bask in the glory of our efforts.

  trip_planner = TripPlanner.new
  trip_planner.start

This means that TripPlanner will have the following attributes and methods:

Attributes

TripPlanner will need to keep track of a user, the forecast, and the recommendation. These attributes should be read only, there's no reason for the main program flow to have to change them directly.

Methods

TripPlanner#initialize

Our initialize will be funny, in that it won't do anything, or take any parameters.

TripPlanner#start

Start is where the action happens. Start, as a method, should do these things:

• Assign the result of .create_user to @user
• Assign the result of .retrieve_forecast to @forecast
• Assign the result of .create_recommendation to @recommendation
• Report the forecast and recommendation, and save it to a file

TripPlanner#create_user

As the method name suggests, it should ask the person at the keyboard for their name, destination city, and duration of the trip. It will then call User.new, passing along that information, and storing it in @user.

TripPlanner#retrieve_forecast

This method will make the actual call to the API, and do the parsing of the data the API returns.

It should strip only the information useful to create Weather objects, described below, and then create and store the array of weather objects in @forecast

Hint: It might help to have some additional helper methods to keep .retrieve_forecast slim. I would suggest having call_api and parse_result methods.

TripPlanner#create_recommendation

This method will take the @forecast array, and create the actual recommendation for your trip.

Hint: Again, I would create a few helper methods to implement this. Perhaps: collect_clothes, collect_accessories, display_recommendation, save_recommendation.

Part 2 - Weather

Since the TripPlanner will store the forecast as an array of Weather objects, I suppose we should have a Weather Class.

The weather object will be responsible for suggesting clothing and accessories based on the min_temp, max_temp, and condition

Attributes

We're only going to care about min_temp, max_temp, and condition when it comes to making decisions about the day. Again, we won't need to change these during the course of the program, so just make them readable.

We'll also do something totally new: the Weather class will be much more usable if we create two separate class constants: CLOTHES and ACCESSORIES. Here's something to get you started:

class Weather
  CLOTHES = [
    {
      min_temp: -50, max_temp: 0,
      suggestions: [
        "insulated parka", "long underwear", "fleece-lined jeans",
        "mittens", "knit hat", "chunky scarf"
      ]
    }
  ]

  ACCESSORIES = [
    {
      condition: "Rainy",
      suggestions: [
        "galoshes", "umbrella"
      ]
    }
  ]
end

These are arrays of hashes, where the first one allows us to search by range and the second by condition.

For methods inside the class, you can just access these constants as written: ACCESSORIES[0][:condition] or CLOTHES[0][:suggestions], etc.

Methods

Weather#appropriate_clothing

Appropriate clothing depends on what temperatures you'll have to endure for the day. This method should utilize the class method Weather::clothing_for to grab the clothing for the max and min temps, and return those results as an array of suggestions without repeat.

Weather#appropriate_accessories

Appropriate accessories depend on what conditions you'll face that day. This method should utilize the class method Weather::accessories_for to grab the accessories for the condition, and return those results as an array of suggestions without repeat.

Class Methods

To make the previous two methods easier to implement, let's create two class level methods to do the actual lookup with our constants:

Weather::clothing_for

This class should actually do the heavy lifting for Weather#appropriate_clothing. It should select and map from the CLOTHES array the suggestions appropriate for condition.

Weather::accessories_for

This class should actually do the heavy lifting for Weather#appropriate_accessories. It should select and map from the ACCESSORIES array the suggestions appropriate for condition.

Part C - User

Attributes

Here we want to store (and leave alone) their name, and the destination and duration for their trip.