Refactoring Rails Apps with Engines

Having an app broken into small, loosely coupled, highly cohesive components is great. Using Rails Engines is one way to do this, but how do you take an existing monolithic Rails app and convert it to use Engines?

This talk will walk through Benjamin’s experience of refactoring a Rails codebase with zero Engines to an architecture with 40 different Rails Engines. He will also compare and contrast with another Rails application he built from the ground up using an Engines architecture. Not only will this talk include lessons learned, it will also feature concrete step by step instructions needed to smoothly refactor your codebase into an Engines based architecture.

Transcript

1. Refactoring Rails Apps with Engines Benjamin Smith @benjamin_smith
2. Why should you care about Engines? @benjamin_smith
3. rails new my_cute_little_app @benjamin_smith
4. Features Time
6. @benjamin_smith
8. 1 Year @benjamin_smith
9. 2 Years @benjamin_smith
10. 3+ Year @benjamin_smith
11. Features Time @benjamin_smith
13. @benjamin_smith
14. Engines to the Rescue! @benjamin_smith
16. Rails @benjamin_smith
17. Rails @benjamin_smith
18. What is an Engine anyway? @benjamin_smith
20. Engines for Architecture @benjamin_smith
21. @benjamin_smith
22. @benjamin_smith
23. @benjamin_smith
24. @benjamin_smith
25. Engines from Day 1 @benjamin_smith
26. @benjamin_smith
27. @benjamin_smith
28. Engines from Day 182.5 @benjamin_smith
29. class User < ActiveRecord::Base @benjamin_smith
30. @benjamin_smith
40. Features Time @benjamin_smith
41. Features Time @benjamin_smith
45. Exact lowest level dependencies first @benjamin_smith
46. has_many ? @benjamin_smith
48. no has_many @benjamin_smith
49. @user.posts @benjamin_smith
50. Post.where(user_id: @user.id) @benjamin_smith
51. Post.for_user_id(@user.id) @benjamin_smith
54. Tests within Engines @benjamin_smith
56. what about controllers and views? @benjamin_smith
57. @benjamin_smith
58. controllers and views all in the Main Rails App @benjamin_smith
59. One model and table per Engine @benjamin_smith
60. Lots of Engines @benjamin_smith
61. Lots of Engines @benjamin_smith
62. Refactor as you go @benjamin_smith
63. 1 month of existing code == 1 week of refactoring @benjamin_smith
65. A Web of Engines @benjamin_smith
66. Product Owner Architecture @benjamin_smith
69. Aggregate Engines @benjamin_smith
84. Features Time @benjamin_smith
87. Thanks! @benjamin_smith
88. @benjamin_smith Component Based Rails Architecture Info cbra.info
89. Come find me for questions! @benjamin_smith cbra.info