Slide 1
Slide 1 text
Callbacks
core_ext
Concerns
Current
Page refreshes
Helpers
@vars
in
views
Seven deadly Rails anti-patterns
Sin City Ruby 2024
Vladimir Dementyev
Evil Martians
?
Slide 2
Slide 2 text
palkan_tula
palkan
2
Rails anti-patterns
Software design patterns and ideas
employed and/or encouraged by
the framework that make developers
hellishly productive (but come with a risk
of poor maintainability in the long term)
the framework
productive
poor maintainability
Deal with the Devil
Slide 3
Slide 3 text
3
Slide 4
Slide 4 text
palkan_tula
palkan
Rails Way
4
Slide 5
Slide 5 text
palkan_tula
palkan
5
github.com/palkan
Slide 6
Slide 6 text
palkan_tula
palkan
6
evilmartians.com
Slide 7
Slide 7 text
palkan_tula
palkan
7
Slide 8
Slide 8 text
8
Slide 9
Slide 9 text
+ palkan_tula
palkan
9
Callbacks
core_ext
Concerns
Current
Page refreshes
Helpers
@vars
in
views
Slide 10
Slide 10 text
+ palkan_tula
palkan
10
Callbacks
core_ext
Concerns
Current
Page refreshes
Helpers
@vars
in views
Slide 11
Slide 11 text
+ palkan_tula
palkan
11
Disclaimer:
I'm actively using (almost) all seven
Confession
Slide 12
Slide 12 text
Callbacks
Slide 13
Slide 13 text
+ palkan_tula
palkan
X
Slide 14
Slide 14 text
14
Slide 15
Slide 15 text
“The deeper callbacks lie in
the architecture layer
hierarchy, the more
dangerous they can be”
–Me @ Layered Rails
15
Slide 16
Slide 16 text
palkan_tula
palkan
Callbacks
16
Channels
Jobs
Mailers
Models
Controllers ⚠
Slide 17
Slide 17 text
palkan_tula
palkan
17
class User < ApplicationRecord
end
Maintainability
Slide 18
Slide 18 text
palkan_tula
palkan
18
class User < ApplicationRecord
before_validation :normalize_email
end
Maintainability
Slide 19
Slide 19 text
palkan_tula
palkan
19
class User < ApplicationRecord
before_validation :normalize_email
after_create_commit :send_welcome_email
end
Maintainability
Slide 20
Slide 20 text
palkan_tula
palkan
20
class User < ApplicationRecord
before_validation :normalize_email
after_create :generate_initial_project
after_create_commit :send_welcome_email
end
Maintainability
Slide 21
Slide 21 text
palkan_tula
palkan
21
class User < ApplicationRecord
before_validation :slugify, on: :create
before_validation :normalize_email
after_create :generate_initial_project
after_create_commit :send_welcome_email
end
Maintainability
Slide 22
Slide 22 text
palkan_tula
palkan
22
class User < ApplicationRecord
before_validation :slugify, on: :create
before_validation :normalize_email
after_create :generate_initial_project,
after_create_commit :send_welcome_email
after_create_commit :send_analytics_event
after_commit :sync_with_crm
end
Maintainability
Slide 23
Slide 23 text
palkan_tula
palkan
23
class User < ApplicationRecord
before_validation :slugify, on: :create
before_validation :normalize_email
after_create :generate_initial_project,
after_create_commit :send_welcome_email
after_create_commit :send_analytics_event,
if: :tracking_consent?
after_commit :sync_with_crm
end
Maintainability
Slide 24
Slide 24 text
palkan_tula
palkan
class User < ApplicationRecord
before_validation :slugify, on: :create
before_validation :normalize_email
after_create :generate_initial_project,
unless: :admin?
after_create_commit :send_welcome_email
after_create_commit :send_analytics_event,
if: :tracking_consent?
after_commit :sync_with_crm
end
24
Maintainability
Slide 25
Slide 25 text
+ palkan_tula
palkan
25
(De-)Normalization
Essential side-effects (audit, etc.)
Conditional
Peripheral side-effects (third-party
integrations, etc.)
Model Callbacks
Slide 26
Slide 26 text
Concerns
Slide 27
Slide 27 text
“A concern is a module that
you extract to split the
implementation of a class in
coherent chunks, instead of
having one big class body.”
–Xavier Noria
27
coherent chunks
Slide 28
Slide 28 text
palkan_tula
palkan
28
class Account < ApplicationRecord
include Account::Associations
include Account::Validations
include Account::Scopes
include Account::Callbacks
end
Cohesion
Maintainability
Slide 29
Slide 29 text
palkan_tula
palkan
Coherent Chunks
29
class Identity < ApplicationRecord
include Accessor, Authenticable, Boxes, Clearance,
Preapproval, Clipper, Creator, Eventable,
Examiner, Filer, Member, PasswordReset,
Poster, Reaching, Regional, TopicMerger
end
God-blessed concerns
Maintainability
Slide 30
Slide 30 text
+ palkan_tula
palkan
30
No isolation (potential hidden/circular
dependencies)
Naming is hard (modules, methods)
Complicated testing
Many Modules
Maintainability
Slide 31
Slide 31 text
+ palkan_tula
palkan
Many
32
No isolation (potential hidden/circular
dependencies)
Naming is hard (modules, methods)
Complicated testing
Many callbacks
Concerns
Maintainability
Slide 32
Slide 32 text
Many Objects
Maintainability
Slide 33
Slide 33 text
+ palkan_tula
palkan
34
Value objects
Workflows (state machines)
Associated models
Store models
Extracting
Prefer objects over concerns...
gem "active_record-associated_object"
gem "store_model"
Slide 34
Slide 34 text
35
codewithjason.com
Slide 35
Slide 35 text
+ palkan_tula
palkan
36
Associations
Active Record extensions (e.g., soft
deletion)
Gluing associated objects and host
models the Rails Way
Concerning
...but remember to stay productive
Slide 36
Slide 36 text
palkan_tula
palkan
37
module Account::Terminable
def terminate
purge_or_incinerate if terminable?
end
private
def purge_or_incinerate
purgeable? ? purge : incinerate
end
# def purge
# def incinerate
# ...
end
Slide 37
Slide 37 text
palkan_tula
palkan
38
class Account::Terminator
def initialize(account) = @account = account
def perform
purge_or_incinerate if terminable?
end
private
def purge_or_incinerate
purgeable? ? purge : incinerate
end
# def purge
# def incinerate
# ...
end
Slide 38
Slide 38 text
palkan_tula
palkan
39
account.terminate #=> Rails-ish!
Account::Terminator.new(account)
.perform #=> Boooring...
Slide 39
Slide 39 text
palkan_tula
palkan
40
class Account::Terminator
def initialize(account) = @account = account
def perform
purge_or_incinerate if terminable?
end
private
def purge_or_incinerate
purgeable? ? purge : incinerate
end
# def purge
# def incinerate
# ...
end
Slide 40
Slide 40 text
palkan_tula
palkan
41
class Account
class Terminator
# ...
end
module Terminable
def terminate = Terminator.new(self).perform
end
end
Slide 41
Slide 41 text
+ palkan_tula
palkan
42
Concerns to sweep complexity under
the rug
Concerns to provide Rails-ish interface
and to integrate with Active Record
Objects to truly isolate functionality
Concerns
Slide 42
Slide 42 text
Helpers
Slide 43
Slide 43 text
+ palkan_tula
palkan
44
Bags of random methods
Form a single module shared by all views
Helpers
# Did you know?
config.action_controller.include_all_helpers = false
Slide 44
Slide 44 text
Current
Slide 45
Slide 45 text
46
thevaluable.dev
Slide 46
Slide 46 text
+ palkan_tula
palkan
47
Keep the number of current
attributes small
Always use Current.set(..., &)
Write as upper on the abstraction
stack as possible
Current
Don't let currents take you under
Slide 47
Slide 47 text
@vars in views
Slide 48
Slide 48 text
49
thevaluable.dev
Slide 49
Slide 49 text
+ palkan_tula
palkan
50
Instance variables in controller action
templates are fine (show.html, etc.)
Instance variables in partials
Strict locals in partials
Become friends with erb-lint
@vars in views
Be strict with them (but not too strict)
Slide 50
Slide 50 text
core_ext
Slide 51
Slide 51 text
52
Slide 52
Slide 52 text
+ palkan_tula
palkan
X
Slide 53
Slide 53 text
+ palkan_tula
palkan
54
Learn them, not fight
Adding your own lib/core_ext!*
core_ext
* Or start using refinements
Slide 54
Slide 54 text
Page refreshes
Slide 55
Slide 55 text
palkan_tula
palkan
Page refreshes
56
<%# locals: (conversations:, total_count:) -%>
<%= turbo_stream.update "counter" do %>
<%= render partial: "counter", locals: {total_count:} %>
<% end %>
<%= turbo_stream.append "items" do %>
<%= render partial: "items", locals: {current_conversation:
Current.conversation, conversations:} %>
<% end %>
<%= turbo_stream.update "scroll" do %>
<%= render partial: "scroll", locals: {id: :conversations, scroll_url:
conversation_action_path(operation: :scroll, page: next_page)} %>
<% end %>
<%= turbo_stream.update "list" do %>
<%= render partial: "list", locals: {conversations:, total_count:,
current_conversation: Current.conversation} %>
<% end %>
Slide 56
Slide 56 text
palkan_tula
palkan
Page refreshes
57
broadcast_refresh_to(conversation)
Slide 57
Slide 57 text
+ palkan_tula
palkan
Rails
58
GEt /converstation/2024
Slide 58
Slide 58 text
+ palkan_tula
palkan
Rails
62
Slide 59
Slide 59 text
+ palkan_tula
palkan
65
class Conversation < ApplicationRecord
# Triggers page refresh on EVERY
# record update
broadcasts_refreshes
end
Deadly Combo
Callbacks meet page refreshes
Slide 60
Slide 60 text
+ palkan_tula
palkan
66
class Conversation < ApplicationRecord
after_commit :broadcast_refresh_later,
if: :should_broadcast?
private def should_broadcast?
# check changed attributes,
# throttle, etc.
end
end
Deadly Combo
Be specific, ship Union Pacific selective updates
Slide 61
Slide 61 text
67
Slide 62
Slide 62 text
+ palkan_tula
palkan
68
<%= cable_ready_updates_for conversation, only:
%w[topic members_count], debounce: 200 do %>
<% # ... %>
<% end %>
Cable Ready?
Is Hotwire really that hot?
Slide 63
Slide 63 text
+ palkan_tula
palkan
69
Beware of multi-user updates
Beware of frequent updates
SolidCache is not an accident
Page refreshes
Slide 64
Slide 64 text
+ palkan_tula
palkan
70
Callbacks
Concerns
Helpers
Core extensions
The Seven
Caution! Sharp knives, use responsibly
Current
@vars in views
Page refreshes
Slide 65
Slide 65 text
71
dev.37signals.com/series/code-i-like/
Slide 66
Slide 66 text
–Me @ Sin City Ruby 2024
“Hell is full of Rails
applications trying to go
against the Rails Way.”
72
Slide 67
Slide 67 text
Slides: evilmartians.com/events
Twitter: @palkan_tula,
@evilmartians
Sin City Ruby 2024
Don't go to Hell