Sometimes you need to create a link to the same page with the current parameters plus some additional params for example link to the pdf format of the same page.

# Using link_to
<%= link_to "Export as PDF", params.merge(format: :pdf) %>
# or assuming the current path is users_path
<%= link_to "Export as PDF", users_path(params.merge(format: :pdf)) %>

# If you just want the url
<%= url_for params.merge(format: :pdf) %>
# or assuming the current path is users_path
<%= users_path(params.merge(format: :pdf)) %>

Related External Links:

• Stack Overflow - link-to-the-current-page-plus-merged-with-a-param