This application provides a user with information related to the spread of COVID-19 internationally. It takes user input in the form of a country code, date, and desired statistic (of daily deaths, daily new cases, total cases, total deaths and total recoveries) and returns a number taken from an API relying on up-to-date World Health Organisation data. The application solves the problem of individuals needing to access information relating to public health, but being overwhelmed by complicated analyses, large amounts of data, or distracting graphical user interfaces. The goal is to allow concerned individuals to evaluate the comparative severity of the disease in different countries in order to inform their personal decisions, including travel plans, distancing strategy or degree of self-satisfaction. The user will use the application by entering a country, chosing which statistic they wish to view and entering a date. This will return a statistic in the form of a sentence string. The user can use the help menu to view a directory of countries and the codes to be used within the command line arguments, a list of statistics that are available, and instructions on date formatting.
- You must have Ruby installed.
- Download the file via zip or git clone into your folder of choice.
- In your terminal, navigate into src of this project.
- Ensure you have installed bundler gem.
- Run:
bundle installThis app takes three terminal line arguments: country, date and statistic.
For example, from the src directory, you can run:
ruby controller.rb -c "AU" -d "20 April 2020" -s "toll" This will return the total deaths from coronavirus in Australia on 20 April this year.
If you forget these instructions, just run the --help command.
ruby controller.rb -hThe available statistics are:
New --> returns the new cases of coronavirus on this day Deaths --> returns the number of deaths from coronavirus on this day Total --> returns the total number of coronavirus cases on this day Recovered --> returns the number of people who have recovered from coronavirus Toll --> returns the total number of deaths from coronavirus
The countries whose statistics can be accessed are:
AF Afghanistan DE Germany PK Pakistan
AL Albania GH Ghana PS Palestine
DZ Algeria GR Greece PA Panama
AO Angola GL Greenland PG Papua New Guinea
AR Argentina GT Guatemala PY Paraguay
AM Armenia GN Guinea PE Peru
AU Australia GW Guinea-Bissau PH Philippines
AT Austria GY Guyana PL Poland
AZ Azerbaijan HT Haiti PT Portugal
BS Bahamas HN Honduras PR Puerto Rico
BD Bangladesh HK Hong Kong QA Qatar
BY Belarus HU Hungary XK Republic of Kosovo
BE Belgium IS Iceland RO Romania
BZ Belize IN India RU Russia
BJ Benin ID Indonesia RW Rwanda
BT Bhutan IR Iran SA Saudi Arabia
BO Bolivia IQ Iraq SN Senegal
BA Bosnia/Herz IE Ireland RS Serbia
BW Botswana IL Israel SL Sierra Leone
BR Brazil IT Italy SG Singapore
BN Brunei JM Jamaica SK Slovakia
BG Bulgaria JP Japan SI Slovenia
BF Burkina Faso JO Jordan SB Solomon Islands
BI Burundi KZ Kazakhstan SO Somalia
KH Cambodia KE Kenya ZA South Africa
CM Cameroon KP Korea KR South Korea
CA Canada XK Kosovo SS South Sudan
CI Ivory Coast KW Kuwait ES Spain
CF CAR KG Kyrgyzstan LK Sri Lanka
TD Chad LA Lao SD Sudan
CL Chile LV Latvia SR Suriname
CN China LB Lebanon SJ Svalbard and Jan Mayen
CO Colombia LS Lesotho SZ Swaziland
CG Congo LR Liberia SE Sweden
CD DR Congo LY Libya CH Switzerland
CR Costa Rica LT Lithuania SY Syrian Arab Republic
HR Croatia LU Luxembourg TW Taiwan
CU Cuba MK Macedonia TJ Tajikistan
CY Cyprus MG Madagascar TZ Tanzania
CZ Czechia MW Malawi TH Thailand
DK Denmark MY Malaysia TL Timor-Leste
DP Diamond Princess ML Mali TG Togo
DJ Djibouti MR Mauritania TT Trinidad and Tobago
DO Dominican Repub MX Mexico TN Tunisia
CD DR Congo MD Moldova TR Turkey
EC Ecuador MN Mongolia TM Turkmenistan
EG Egypt ME Montenegro AE UAE
SV El Salvador MA Morocco UG Uganda
GQ Equatorial GuineaMZ Mozambique GB United Kingdom
ER Eritrea MM Myanmar UA Ukraine
EE Estonia NA Namibia US USA
ET Ethiopia NP Nepal UY Uruguay
FK Falkland Islands NL Netherlands UZ Uzbekistan
FJ Fiji NC New Caledonia VU Vanuatu
FI Finland NZ New Zealand VE Venezuela
FR France NI Nicaragua VN Vietnam
GF French Guiana NE Niger EH Western Sahara
TF French ST NG Nigeria YE Yemen
GA Gabon KP North Korea ZM Zambia
GM Gambia NO Norway ZW Zimbabwe
GE Georgia OM Oman
This app has three features:
- Scrape
This is a module which defines a static function taking three variables as arguments: country, date and statistic. It scrapes a url using the gem open-uri. This url is taken from an online API, and completed as a string using the country argument. The data returned from this is saved into a local variable. Using the json gem, the same function parses this variable and returns the relevant statistic. In order to do this, it uses a private class to define a function which translates the user-entered statistic into a well-formed string. Error handling inherits from the standard class. I have ensured that user input which is a date object or wrongly capitalized can be handled.
- Opt-Parse
This is a class for analysing the arguments entered in the command line by the user, using the Option Parser gem which is bundled with ruby. It specifies the arguments which are mandatory - country, date, and statistic - as well as outlining what type of variable it expects these to be, and automatically generates a help menu for the commands. Using the optparse/date module, I can coerce the string entered as an argument for date into a date object. Opt-parse also allows me to store the arguments in a hash, which is used as an argument in the get function described above.
- Main function
This code handles the arguments specified in opt-parse above and returns a string with the scrape module method interpolated. The error handling at this stage rescues an error where there are insufficient arguments and an error where there are invalid arguments and ensures that a well formed error message is returned, which suggests that the user access the help menu.
- Elegant error handling
You will find all of your errors handled in the most elegant of ways. Enter insufficient number of arguments in the terminal? Handled, with a polite error message. Enter a country code that does not exist? Handled, with a polite error message. Enter a date before which no person had yet eaten a bat and coronavirus did not exist? You will be astonished yet delighted to know, this is considered an error, and that error is handled. If there are yet errors, I blame the user.
- Conditionals
You will find that in the cache function, there is a conditional that provides a json file will only be saved to the computer where this file does not already exist, or the existing file does not have data for the date requested. Is that enough double negatives for you?
The user will learn how to interact with the application through a README file accessible on the public github repository. This file will explain how to install the app as well as install any dependencies using bundle install. It will also include usage instructions with examples. During use of the application, if a user enters incorrect information – for example, if a user were to enter too few arguments – the application will prompt the user as to the nature of the error and suggest that they view the help menu of the application by typing --help. These choices have been made to closely mirror how command line applications typically function, rather than mimicking the style of a graphical user interface
The things I need to do to make this app are listed below. As I researched how to do these things and then incorporated the results into my code (while continuously testing to ensure performance was as expected), I checked off the items from the list below in trello.
- Learn how to use github to version control my work
- Write a readme and software development plan including features.
- Make a control flow diagram of how I expect the app to work.
- Write some tests using rspec about how I expect the program to work
- Learn how to make an executable file that takes arguments from the command line using ARGV
- Find an API that will provide corona virus statistics I am interested in.
- Understand the structure of the API and which options I will need to require from the user in order to return a sensible result.
- Find a way to make an http call to the API and return the results as json
- Find a way to parse the result
- Fix the errors that the gem is throwing because of its basic settings
- Write a function which takes the arguments and returns the number I am interested in.
- Find a way of taking arguments from the command line
- Find a way of generating a help menu
- Learn how to make a gem using bundle gem coronapp to create a sensible file structure for my app.
- Make a way of caching results
- Find a way of validating dates entered to ensure that people aren't entering from before or after data exists
See trello board for further details.
| Test | Expected Outcome | Actual Outcome |
|---|---|---|
| I enter a search for Australia | A json file is saved to the cache folder which contains the data from the australia webpage | As expected |
| I enter a search for Australia a second time | The json file above is not modified | As expected |
| I manually remove the date in my search from the saved Australia cache and search again | The json file above is updated to include the date again | As expected |
| I enter a search for -c "AU" -d "20 April 2020" -s "deaths" | I will be returned the string "There were 0 new daily deaths on this day" | As expected |
| I enter a search for -c "AU" -d "40 April 2020" -s "deaths" | I will be returned the message "Invalid argument: -d 40 april 2020. Run "coronapp" --help for details." | As expected |
| I enter a search for -c "AU" -d "20 Fleburary 2020" -s "deaths" | I will be returned the message "Invalid argument: -d 20 Fleburary 2020. Run "coronapp" --help for details." | FAIL - returned "There were new daily deaths on this day" Fix this! |
| I call the help menu | The help menu is returned | As expected |
| I call the app without any arguments | I receive the message "Insufficient arguments. Run "coronapp" --help for details." | As expected |
| I enter a search for -c "XX" -d "20 April 2020" -s "toll" | Mate, I hope it breaks but I'm pretty sure it's not going to because I don't have data validation for this | FAIL - as expected, not having a way of handling this meant that it wasn't handled |
| I enter a search for --cOuNtRy "uS" --dAtE "24/02/2020" -sTaT "tOtAl" | I will be returned the message "There were 51 total cases on this day" | As expected |