Do you have a route to the pdf download or is the file itself a static asset?
You can use a standard link_to
helper with an image_tag
helper to create a clickable image.
For a static pdf asset:
<%= link_to(image_tag('my_image.png'), 'path/to/filename.pdf') %>
This will show the image my_image.png
on the page which when clicked will begin downloading or displaying the static pdf asset.
For a controller action that serves the file:
Page:
<%= link_to(image_tag('my_image.png'), download_pdf_path) %>
Controller:
def download_pdf
send_file 'path/to/filename.pdf'
end
Route:
get 'download_pdf' => 'controller#download_pdf'
This will show the image my_image.png
on the page which when clicked will make a get request to the pdf download action.