How does local_assigns work in Rails?

Question

I\'ve been googling around about this and can\'t find the right path. I\'m working on a Rails app that is using a method called local_assigns. This appears to be something in Ra

Answer 1

local_assigns is a Rails view helper method that you can check whether this partial has been provided with local variables or not.

Here you render a partial with some values, the headline and person will become accessible with predefined value.

<%= render "shared/header", { :headline => "Welcome", :person => person } %>

In shared/header view:

Headline: <%= headline %>
First name: <%= person.first_name %>

Here is how you check these variables has passed in or not:

<% if local_assigns.has_key? :headline %>
  Headline: <%= headline %>
<% end %>

Check this document for more detail on the section Passing local variables to sub templates.