A walkthrough of my CLI GEM
After considering a couple of ideas, I decided I wanted to build an application that showed posts from The DEV Community dev.to, a website where programmers share ideas and help each other grow.
The approach I took was the one recommended by Avi in the CLI Gem Walktrough video, I took it one step at a time.
First, to plan my gem I started imagining the interface, what I wanted the user to see and experience. After welcoming the user I decided the next step should be to display a list of post titles, with their authors and tags. After this I wanted to give the user the option to either read one of the listed posts, list them one more time or exit the program. I Knew I wanted to have those options available at any time.
The next step was to define the project structure. I used Bundler to do this, following some steps from this guide: Developing a RubyGem using Bundler. I ran bundle gem dev_to in my terminal and that built all of the structure for me in advance. I added a config folder with an environment.rb file where I later required all my files and gems.
After this I started working on the entry point of my application, the file run. I added devto to the bin folder and added permisions to execute it in the terminal by entering chmod +x dev_to. This way the program runs through bash using ruby’s interpreter.
This was the moment to start thinking about the code I wish I had. I added DevTo::CLI.new.call to ./bin/devto. This line of code represented the decision to encapsulate all of the CLI interface logic into one object, the CLI class, my Controller. I started working on it following the guide I had set for myself in the beginning. I used harcoded data to be able to quickly see how the interface was shaping up.
Once I had a working interface I moved on to making this dummy data real. I defined two more classes, the Post class and the Scraper class. In the Post class I defined all the attributes my Post objects were going to have: title, author, tags, date, a url and content. The Scraper class was going to be responsible for getting all this data from the dev.to website and make instances of Posts.
I then made these three classes collaborate with each other. The Post class was going to be responsible for keeping track of all the instances of Post created by the Scraper class. This allowed me to define a class method for Post to find instances by id, and show its content to the user. As I had to call the Scraper method to make posts at the beginning of the program to make the instances of Post, I determined it was better to define another method to scrape the content, as I only needed to show the content once the user chose a post to read. I grabbed the user input to find the post’s url in the Scraper make content method, open it with Nokogiri and open-uri and scrape the content and date of the post.
While working with Nokogiri to scrape the data, I found I wanted to show the user the amount of comments and likes each post had, so I added those attributes in the Post class (I used the attr_accessor for all the attributes of Post, to be able to read and write to them). I then scraped this data (The Chrome DevTools were, as always, extremely useful in this process) and added it to the CLI method to list the posts.
I wanted the user to see emojis next to the comments and likes count, as displayed in the website. So I started researching how to make that possible and found I could use UNICODE emoji codes. I was able to add them to my code like this: \u{1F4AC} (The numbers and letters inside are specific for each emoji). Another thing I wanted to try was to let the user open the selected post in the browser to keep reading. I was able to achieve this with this code: system("open #{post.url}").
Once all of this was working I decided to try and publish the gem to rubygems.org. I followed a guide from the same website to do this, Publishing your gem. Now you can find my gem here!.
Next steps I have in mind are adding new features, like searching posts by #tag, and write tests. I learned a lot making this gem and loved every step of it, looking forward to making many more.