Blow up when things are wrong

When something unexpected happens, you should know about it immediately to make debugging and fixing the problem easier. Discusses ActiveRecord persistence APIs.

Transcript

1. Blow up when things are wrong ActiveRecord edition Vesa Vänskä, Kisko Labs Helsinki Ruby Brigade, Rails Girls
2. When something is wrong, you should know about it as fast as possible
3. #save vs #save!
4. foo.save! # or if foo.save # success else # fail end
5. The case of updating attributes
6. Validations Callbacks #update_attributes ✔ ✔ #update_attribute ✖ ✔
7. Question
8. Which of #decrement, #decrement!, and #decrement_counter skip validations/ callbacks?
9. Validations Callbacks #decrement ✔ ✖ #decrement! ✖ ✔ #decrement_counter ✖ ✖
10. http://guides.rubyonrails.org/ active_record_validations_callba cks.html
11. ATK Do Not Want RubyGem https://github.com/ garybernhardt/do_not_want
12. Making it simpler
13. In Rails 3.2.7 the #update_attribute method was actually deprecated
14. 14.6.2012 – #update_attribute is deprecated in 3.2 branch 14.6.2012 – #update_attribute was removed from 4.0 branch 24.7.2012 – #update_column was deprecated in 4.0 branch 26.7.2012 – Rails 3.2.7 release 30.7.2012 – #update_column is undeprecated in 4.0 branch 1.8.2012 – #update_attribute is undeprecated in 3.2 branch 25.8.2012 – #update_attribute is put back in 4.0 branch 9.8.2012 – Rails 3.2.8 release
15. • https://github.com/rails/rails/commit/ b081f6b59fb3f15d12043072ad9b331ffd2bc56e • https://github.com/rails/rails/pull/6738 • https://github.com/rails/rails/pull/1190 • https://github.com/rails/rails/commit/ 4ac81de52fbcdabc68f6d1fa8a5ee9ff7fff7df1 • https://github.com/rails/rails/commit/ 50bdb924ba26999a468ec4844917cefec39ba08c • https://github.com/rails/rails/commit/ 81542f95d25825a7d3eff87d6f706661bf553b18 Links
16. I
17. What is the current status?
18. After all this •In Rails 4 the recommended way is to use #update with a hash •#update_attributes is aliased to #update •#update_attribute is still skipping validations
19. Vesa's laws of updating attributes 1. Use #update_attributes or use setters and #save/#save! 2. All other methods of updating attributes need an accompanying comment that explains why you didn't follow the first rule.
20. Useless ActiveResource information •ActiveResource #update_attribute will run validations normally
21. Extra Ruby tip
22. {foo: "bar"}[:foo] {foo: "bar"}.fetch(:foo)
23. {foo: "bar"}[:foo] #=> "bar" {foo: "bar"}.fetch(:foo) #=> "bar"
24. {foo: "bar"}[:whatevs] {foo: "bar"}.fetch(:whatevs)
25. {foo: "bar"}[:whatevs] #=> nil {foo: "bar"}.fetch(:whatevs) #=> KeyError: key not found: :whatevs
26. {foo: "bar"} .fetch(:whatevs, :not_found) #=> :not_found {foo: "bar"} .fetch(:whatevs) { 1 + 1 } #=> 2
27. Thank you! twitter.com/vesan vesavanska.com