You installed some gems that install a binary (like bundle, rake or rails) with code that only works with modern Rubygems versions You downgraded Rubygems to an older...
...require 'mathn' call (usually by wrapping Bundler.require) like this: # config/application.rb MathnWorkaround.intercept do Bundler.require(:default, Rails.env) if defined?(Bundler) # If you require "mathn" manually, put it inside this block. end
Re-creating a complex ActiveRecord scenario quickly without setting up a full-blown Rails app can come in handy e.g. when trying to replicate a presumed bug in ActiveRecord with...
...to your site and still have the serialization of such objects in their session. Rails will then try to rebuild the user's session and raise an error out of...
If you use a form (or form fields) multiple times inside one view, Rails will generate the same id attributes for fields again. This card presents you with a way...
...other schema names when working with a (legacy) application's database. Note that for Rails applications, dropping and recreating the database itself is usually fine in development. You can use...
...param is a string and you don't get the magic type casting that Rails would give you if it was an actual database column. E.g. when you set an...
...More than twice the amount of courses is probably not sensible, booting up rails takes its time, too...
...simple definition of meta-programming macros like the has_many that you know from Rails. Modularity also lets you organize large models into multiple source files in a way that...
...to Cucumber that helps integration-testing command line tools. When your tests involve a Rails test application, your tool's Bundler environment will shadow that of the test application. To...
...be docked to I18n (configured explicitly on plain Ruby, or use .yml files for Rails): "one & two".convert_miscellaneous_characters # => "one and two" "my words".convert_miscellaneous_html_entities...
...column" ASC NULLS FIRST Your indexes will have to specify this as well. In Rails, declare them using add_index :table, :column, order: { column: 'DESC NULLS LAST' } Multiple columns
...param is a string and you don't get the magic type casting that Rails would give you if it was an actual database column. One effect is that when...
Note: This applies to plain Ruby scripts, Rails does not have this issue. When you work with Ruby strings, those strings will get some default encoding, depending on how they...
...need to represent later time values, use the DateTime class. This is also what Rails does when it loads a record from the database that has a DATETIME value which...
...class: 'image-preview' The image_tag will either contain an existing image (rendered by Rails) or be overwritten by Unpoly with an image preview. Testing Here's a Cucumber step...
...using Middleman for some static sites like our blog. Despite being very similar to Rails, Middleman does not add a fingerprint hash to its asset paths by default. This means...
...a low-level Ruby message like Fix: "undefined method `bytesize' for #" or the standard Rails error box. You will not get an exception notification per e-mail or Airbrake.
ActiveModel::Errors is used to handle validation errors on Rails objects. If you inspect an instance, it feels like a hash (to be more precise, it inherits from Hash):
Enumerable#grep_v excludes from the result set. It's similar to Rails' #reject: ['foo', 1, 'bar', {}].grep String # => ['foo', 'bar'] ['foo', 1, 'bar', {}].grep_v String...
...user symbol in the hash of inclusions turned into a "user" string.\ This breaks Rails' loading of associations as it will complain about calling nil.name or nil.macro while it tries...
...Otherwise add database_cleaner to your *Gemfile`. This lets you say this from the Rails console: DatabaseCleaner.strategy = :truncation DatabaseCleaner.clean You can package this into a nice little Rake task by...
...can e.g. clean the test database by saying on the shell: rake db:clean RAILS_ENV=test If you are using the parallel_tests gem, the task is aware and...
ActiveSupport::Memoizable will be removed from Rails and has a lot of strange caveats that will ruin your day. Use the Memoizer gem instead. It works in all past and...
...future Railses and has none of the annoying "features" of ActiveSupport::Memoizable. It just does memoization and does it well. The syntax is similiar also: class Foo include Memoizer
...you set both a record's association and that association's foreign key attribute, Rails does not realize you are talking about the same thing. The association change will win...