World-Covid-Staus CLI App is programmed by Ruby and is to show current status of Covid-19 by country. It is to scrape data from “https://www.worldometers.info/coronavirus/"
Scraping HTML Using Nokogiri and Open-URI
It searches the corresponding table from the end point and scrapes table id main_table_countries_today
World-Covid-Status CLI Structure
├── bin
│ └── world-covid-status
├── config
│ └── environment.rb
├── db
│ └── countries.db
├── lib
│ ├── world_covid_status
│ │ ├── cli.rb
│ │ ├── country.rb
│ │ ├── world-covid-status
│ │ └── util.rb
│ └── world_covid_status.rb
└── README.mdHow to execute the CLI
Type ruby bin/world-covid-status on bash terminal.
Features
When the app is running, you can see 10 rows of offset, order by Population, Total cases and Active Cases. The ranking range is between 1 to 100. By entering Country Code(the last column), you can see more information of the country. You can quit the app at anytime by Q/q input.
Breif Summary of Execution Flow
ruby bin/world-covid-status initiates Command Line Interface, cli.rb. cli.rb calls scraper.rb, which scrapes HTML and extracts data we want. Then scraper.rb initializes country.rb that saves data into database and manipulates.
Error Handling
In cli.rb, it handles exception by user's input.
Other Useful Information
Change font color in bash CLI
You can find def font_color in util.rb, which sets font color to yellow, red and blue.
Check caller function
When you need to check caller method, you can compare caller name with caller[0][/`([^’]*)’/, 1]
Escape line break in long string
By putting (back slash) in the end of line, you can escape from line break. But you have to make sure no white space after .
