ActionView::Helpers::CsrfHelper
Methods
C
Instance Public methods
csrf_meta_tag()

For backwards compatibility.

Alias for: csrf_meta_tags
csrf_meta_tags()

Returns meta tags “csrf-param” and “csrf-token” with the name of the cross-site request forgery protection parameter and token, respectively.

<head>
  <%= csrf_meta_tags %>
</head>

These are used to generate the dynamic forms that implement non-remote links with :method.

You don't need to use these tags for regular forms as they generate their own hidden fields.

For AJAX requests other than GETs, extract the “csrf-token” from the meta-tag and send as the “X-CSRF-Token” HTTP header. If you are using jQuery with jquery-rails this happens automatically.

Also aliased as: csrf_meta_tag

Source: show | on GitHub 

# File actionview/lib/action_view/helpers/csrf_helper.rb, line 20
def csrf_meta_tags
  if protect_against_forgery?
    [
      tag("meta", name: "csrf-param", content: request_forgery_protection_token),
      tag("meta", name: "csrf-token", content: form_authenticity_token)
    ].join("\n").html_safe
  end
end