Look out for a number that keeps growing over time. Rails In a Rails application, you can use derailed_benchmarks to identify and examine memory leaks.
...more than changing tables (like, modify many records) you may want some output. In Rails > 3.1 you have two methods at hand: announce and say_with_time. In the migration...
...want to find all Decks without any Card or all Cards without a Deck. Rails 6.1+ Rails 6.1 introduced a handy method ActiveRecord#missing to find records without given associations...
ON "decks"."id" = "cards"."deck_id" WHERE "decks"."id" IS NULL Older Rails versions If you don't have Rails 6.1 yet, you can use this not-so...
If validations failed for a record, and you want to find out if a specific validation failed, you can leverage...
...pass a :status option: get '/stories', to: redirect('/articles', status: 302) Note By default Rails sends a header Cache-Control: max-age=0, private, must-revalidate with all responses, including...
ActionMailer per default uses http as protocol, which enables SSL-stripping. When a logged-in user follows an http link...
Since Rails 6+ you can use before? and after? to check if a date/time is before or after another date/time. Example christmas = Date.parse('24.12.2022') date_of_buying_a...
tl;dr You should decouple migrations from models by embedding models into the migration. To use STI in this scenario...
In Rails 5+ you can access a helper from a controller using the helpers method: # Inside a controller action helpers.link_to 'Foo', foo_path In older Rails versions you can...
The benefit of the Rails asset pipeline is that it compiles your stylesheets and javascripts to a single file, respectively. However, the consequences are startling if you don't understand...
...gave every library its own "root" folder. First, add this line to your config/initializers/assets.rb: Rails.application.config.assets.paths += Dir["#{Rails.root}/vendor/asset-libs/*"].sort_by { |dir| -dir.size } This will tell Rails about the custom asset...
To read the Rails session from a Rack middleware, use env['rack.session']. It's an ActionDispatch::Request::Session object. class MyMiddlware def initialize(app) @app = app end def call(env...
...status, headers, body = @app.call(env) session = env['rack.session'] Rails.logger.info("Value of session['foo'] is: " + session['foo'].inspect) [status, headers, body] end end You may not be able to write to...
...a situation in which I received the yarn integrity check warning when starting the rails console even though everything was up to date and correct versions in use.
I tried starting the rails console without switching to the correct node version first and received the yarn integrity warning. warning Integrity check: System parameters don't match...
If your irb or rails console keeps randomly crashing and you can't figure out why then you can try to disable multi-line autocomplete...
Starting from Rails 4.0, you can use a special form options helper called #collection_check_boxes. It behaves similar to #collection_select, but instead of a single select field it...
Note the hidden input at the end. This is a trick that Rails uses so users can uncheck all the check boxes. If this hidden input wasn't...
To ensure Spring is not running: bin/spring stop pkill -f spring To prevent Spring from starting again: export DISABLE_SPRING...
The linked content includes a few design patterns implemented with Ruby on Rails. What is the card indented to achieve? You can use the pattern names for code reviews, so...
} } } } } Integration in Rails + searchkick Was benötigt man für Integration von Elastic in eine Rails-Anwendung? Mindestens: Client um mit Elastic zu reden Erzeugen von Indexen, passender Mappings + Migration...
Sometimes you want to have a time in a given timezone independent from you Rails timezone settings / system timezone. I usually have this use case in tests. Example
...return different results e.g. 2020-08-09 00:00:00 +0200 depending on the Rails timezone settings / system timezone. But in this example we always want to have the given...
The author describes his little journey in hunting down a memory leak. Maybe his approach and tooling may one day...
Rails defines a #truncate helper as well as a method String#truncate. = truncate("my string", length: 5) = "my string".truncate(5) Both are really similar; in fact, the helper invokes...
...Gruff for easily plotting graphs. It is written in pure Ruby and integrates with Rails applications. It provides features as automatic sizing of dots and lines (the more values, the...
...restart your development server.) Usage This is a common example for graph generation in Rails. Note that you have many configuration options at hand that are not documented. Github and...
Create, or edit your ~/.irbrc file to include: require 'irb/ext/eval_history' # was 'irb/ext/save-history' for versions prior to Ruby 3.3 IRB.conf[:SAVE...
You can use record.send(:update_without_callbacks) or record.send(:create_without_callbacks) This can be used as a lightweight alternative to machinist's make or FactoryGirl's create...
...return the object, so you might want to do record = Record.new.tap(&:create_without_callbacks) Rails 3 Rails 3 no longer comes with update_without_callbacks or create_without_callbacks. There...
When logging in Rails, you can use the log_tags configuration option to add extra information to each line, like :request_id or :subdomain. However, those are only valid inside...
...log entries which are mixed together. Welcome to debugging hell. You want something like Rails' :request_id tagging. This can easily be achieved through a Sidekiq middleware as follows.