url_for with added params

Rails' url_for is useful for generating routes from a Hash, but can lead to an [open redirect vulnerability](https://cheatsheetseries.owasp.org/cheatsheets/Unvalidated_Red...

When using form_for you can give the form's target URL either as a string or an array:

form_for(admin_user_path(@user)) do ... end
# same as:
form_for([:admin, @user]) do ... end

Same for link_to:

link_to("Label", edit_admin_u...

When you generate a URL in a mailer view, ActionMailer will raise an error unless you previously configured it which hostname to use.

There are t...

You know that you can force absolute URLs throughout a response. Now you want to modify URLs similarly, but only in parts of a view (or controller) logic. H...

When HTTP clients make an request they can define which response formats they can process. They do it by adding a header to the HTTP request like this:

Accept: application/json

This means the client will only understand JSON respon...

TL;DR There are three dimensions you can control when scoping routes:

scope module: 'module', path: 'path', as: 'as' do
  resources :examples, only: :index
end

→ Path Helpers: as_examples_path and as_examples_url
→ URLs: `/pat...

If you need to modify (e.g. add 2px) a Sass variable that defines multiple values as one (e.g. for short-hand CSS definitions such ass padding), you can by using nth. It's ugly.

While you could split up such variables into multiple values (e....

Be careful!
The following solution will delete files on a volume. If you don't know exactly what you're doing, you can run into big trouble with your computer.

I play mp3 files on my car stereo that are stored on a SD-C...

The following snippet demonstrates how you could create excel files (with spreadsheet gem) and format columns so that they follow a specific number format like currencies or dates do.

require 'rubygems...