Adding Polymorphic Comments to Posts in Ruby on Rails

If a blog post has no comments, was it ever posted? Comments are a common thing to have within any application. In this episode, I'll be adding the comments model and the list controller, as well as building out stubs for the upcoming episode dealing with the rest of the CRUD actions (create, update, delete) for comments. I'll discuss polymorphism within the model and how Rails uses it. We'll add a counter cache to keep track of the number of comments as well.
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⏱️ Timestamps:
  • 00:00 - Introduction
  • 00:35 - code coverage results
  • 01:00 - comments migration - what is polymorphism?
  • 05:00 - comment model
  • 06:00 - comment association, validations, logic
  • 09:30 - commentable concern
  • 10:40 - other changes
  • 11:30 - comments controller, policy
  • 13:35 - tests

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  • Comments
  • Polymorphism
  • Counter Cache


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My name is David W Parker and I’m creating and publishing videos on ProgrammingTIL to help teach anyone and everyone who wants to code. I’m a huge fan of Ruby on Rails, Svelte, TailwindCSS, and WebGL. I’ve used React a lot in the past, as well as some Vue and AngularJS. I’ve done some professional Python and Django. I like to create real applications and my tutorials will walk you through how to build something real from beginning-to-end.

ruby #rails #rubyonrails