variant=

Sets the variant for the response template.

When determining which template to render, Action View will incorporate all variants from the request. For example, if an `ArticlesController#index` action needs to respond to `request.variant = [:ios, :turbo_native]`, it will render the first template file it can find in the following list:

• `app/views/articles/index.html+ios.erb`

• `app/views/articles/index.html+turbo_native.erb`

• `app/views/articles/index.html.erb`

Variants add context to the requests that views render appropriately. Variant names are arbitrary, and can communicate anything from the request’s platform (`:android`, `:ios`, `:linux`, `:macos`, `:windows`) to its browser (`:chrome`, `:edge`, `:firefox`, `:safari`), to the type of user (`:admin`, `:guest`, `:user`).

Note: Adding many new variant templates with similarities to existing template files can make maintaining your view code more difficult.

#### Parameters

• `variant` - a symbol name or an array of symbol names for variants used to render the response template

#### Examples

class ApplicationController < ActionController::Base
  before_action :determine_variants

  private
    def determine_variants
      variants = []

      # some code to determine the variant(s) to use

      variants << :ios if request.user_agent.include?("iOS")
      variants << :turbo_native if request.user_agent.include?("Turbo Native")

      request.variant = variants
    end
end