Update: This is now documented on Edgeguides Ruby on Rails: If you set the :validate option to true, then associated objects will be validated whenever you save this...
...default, this is false: associated objects will not be validated when this object is saved. Setup # post.rb class Post < ActiveRecord::Base has_one :attachment end # attachment.rb class Attachment < ActiveRecord::Base...
...really want to get their arguments processable as keyword arguments. Don't change the syntax, or you'll experience pain. Always call super inside of your overridden #initialize method. A...
...things happen in the ActiveRecord world. Just let them happen, otherwise kittens will die somewhere. You don't want that. Example class Item < ActiveType::Object def initialize(attributes) super
For searching in large database tables we usually use PostgreSQL's fulltext search capabilities. While this works reasonably well for content primarily consisting of prose, it is not necessarily a...
...good solution for all use cases. The main issue is that it is only possible to search for prefixes of text tokens, which can potentially be unexpected for users.
to create a Gallery that has a name and has_many :images, which in turn have a caption to offer the user a single form to create...
...with any number of images immediate uploads with a progress bar per image a snappy UI Enter jQuery File Upload. It's a mature library that can do the job...
When you need to see the content of a page (i.e. not all the HTML but the relevant text body) you can do pp (html_content) pp will format the...
...html String human readable pretty printed where html_content can be replaced by one of the following commands: Rails body or response.body Capybara: page.driver.html.content page.body Webrat: Nokogiri::HTML(response.body).content...
When you want to filter records in a model where a string column roughly matches a given term, you can use PostgreSQL’s trigram similarity search. Writing a fuzzy query...
User.where("similarity(name, ?) > 0.3", "John") This finds all users where the name is similar to "John" with a similarity score above 0.3. You can tune the threshold:
Rails comes with a Rake task notes that shows code comments that start with "TODO", "FIXME", or "OPTIMIZE". While it's generally not good practice to leave them in your...
...not yet available. To keep track of them, run rake notes. Its output looks something like this: $ rake notes app/controllers/frontend/media_documents_controller.rb: * [ 6] [TODO] should be part of a publication workflow app/helpers/frontend/slider_helper.rb...
Ever wondered how you can create a simple table output in bash? You can use the tool column for creating a simple table output. Column gives you the possibility to...
...same level. Pipe output to column -t (maybe configure the delimeter with -s) and see the magic happening. detailed example I needed to separate a list of databases and their...
When you need to store structured data (like Ruby hashes) in a single database column with ActiveRecord, a simple way is to use PostgreSQL's jsonb columns. ActiveRecord will automatically...
...serialize and deserialize your Hash to and from JSON, and you can index JSON paths for fast reads. As an alternative, ActiveRecord::Store offers a way to store hashes in...
...window manager that provides neat features like automatic layouting of windows, good multi-display support with per display workspaces and more. Since it is only a window manager, you will...
...menus, automatic updates etc. Fortunately, you can run Awesome within MATE, by following these steps (tested on Ubuntu MATE 16.04): Awesome + MATE Create the following file at /usr/share/xsessions/Xsession.desktop: [Desktop Entry...
Boot partitions from installations prior to the 16.04 era are terribly small. When you install updates and encounter errors due to a full /boot partition, consider risizing it.
...can't do the steps described below, ask someone experienced to help you out. This has worked 100% so far. 1 out of 1 tries. ;) Scenario A: There is unassigned...
If you want to build a small CLI application, that supports more advanced inputs than gets, I recommend using the cli-ui gem. It's a small dependency-free library...
...that provides basic building blocks, like an interactive prompt: require "cli/ui" CLI::UI::StdoutRouter.enable puts CLI::UI.fmt "a small {{red:demo}}" # supports h, j, k, l, arrows and even filtering...
In Rails 3.1+, instead of defining a separate up and down method you can define a single method change: class AddComparisonFieldsToReport < ActiveRecord::Migration def change add_column :reports, :compare, :boolean...
...update "UPDATE reports SET compare = #{quoted_false}" add_column :reports, :compare_start_date, :date add_column :reports, :compare_end_date, :date end end Migrating up works as expected:
To set a cookie in your test browser for cucumber tests, you need to know which driver you are using. Use the step below according to your driver.
...to "([^\"]+)"$/ do |key, value| headers = {} Rack::Utils.set_cookie_header!(headers, key, value) cookie_string = headers['Set-Cookie'] Capybara.current_session.driver.browser.set_cookie(cookie_string) end Note that Rack::Utils is only used to...
Select2 is a fantastic library for advanced dropdown boxes, but it depends on jQuery. Alternatives Tom Select There is a selectize.js fork called Tom Select. It is well tested, comes...
...with Bootstrap 3, Bootstrap 4 and Bootstrap 5 styles and is easy to use. You might miss some advanced features. Known issues: Dynamic opt-groups in AJAX requests are not...
...Chrome to check if the problem disappears. Keep in mind though that running outdated software, especially web browsers, is in most cases not a good idea. Please verify periodically if...
...you still need to run the old version or if an even more recently updated version fixes the problems introduced in your version. Here's how to get old versions...
...not possible to use variables in media queries with plain CSS. @media (max-width: var(--some-pixel-size)) {...
...} /* Does not work */ Postcss Plugin If you're using PostCSS to postprocess...
...your CSS, you can configure postcss-custom-media and add this feature: @custom-media --small-variable-name(max-width: 968px); @media (--small-variable-name) {...
Note The plugin does not...
...ae]y => grey or gray => but NOT graay or graey [0-9] matches a SINGLE digit in the range from 0 to 9 [0-9a-fA-F] hexadecimal digit...
...with caution. Mostly you'll want to use it for small expressions, e.g. for nested sub-regexes. For more details have a look at the card on quantifier modes.
Starting Terminator with split screens is quite simple: Just store a layout and start Terminator with the --layout option. However, if you want to run custom commands in your terminals...
...command exits. You accomplish this by tweaking bash to run a command before actually starting. Pimp your .bashrc Add this to the end of .bashrc: # hack to keep a bash...
Git log offers useful options for filtering. This card provides a short overview. By message Only commits that include a specific string in their commit message git log --grep="tracker...
By file Only commits that introduced changes to a specific file git log -- foo.rb bar.rb Note In case the file was renamed or moved the --follow option can be...
...are usually believed to have worse performance than those defined via def. Hence, developers sometimes prefer using class_eval to define methods using def, like this: class_eval "def #{attribute...
...for_realsies?; do_things; end" You can benchmark methods defined like this and will see that those defined via def actually do perform better. Basically, it ranks like this:
...version understands? Did you double-check your @font-face declarations with all the hacky syntax that is required? Compare them with other declarations you find on the web.
...same name? This usually leads to trouble, but there are workarounds. Do IE's security settings prevent the download of webfonts? (see below) IE Security Settings can prevent font download...
Bundler allows you to specify the name of the Gemfile you want to bundle with the BUNDLE_GEMFILE environment variable. BUNDLE_GEMFILE=Gemfile.rails.7.2 bundle By default, bundler will look...
...have multiple Gemfiles in your project, which cannot all be named Gemfile. Let's say for example, you maintain a gem and want to run automated tests against multiple rails...
This is for people recovering from Subversion. Get an existing from the server for the first time git clone git@example.com:repositoryname See what's changed git status Check in locally...
...git commit -m "good description" Push local commits to the server git push Get and merge updates from the server git pull Stage a file for the next local commit...