How to trigger download with Rails send_data from AJAX post
create a function in controller
def ajax_download send_file "path_to_file/" + params[:file]end
and then in controller action
respond_to do |format| @java_url = "/home/ajax_download?file=#{file_name}" format.js {render :partial => "downloadFile"}end
and make a partial in view folder name with _downloadFile.js.erb and write this line
window.location.href = "<%=@java_url %>"
You can't download a file to disk from JS. It's a security concern. See the blog post below for a good workaround.
Do not just copy and paste the accepted answer. It is a massive security risk that cannot be understated. Although the technique is clever, delivering a file based on a parameter anybody can enter allows access to any file anybody can imagine is lying around.
Here's an example of a more secure way to use the same technique. It assumes there is a user logged in who has an API token, but you should be able to adapt it to your own scenario.
In the action:
current_user.pending_download = file_namecurrent_user.save!respond_to do |format| @java_url = "/ajax_download?token=#{current_user.api_token}" format.js {render :partial => "downloadFile"}end
Create a function in the controller
def ajax_download if params[:token] == current_user.api_token send_file "path_to_file/" + current_user.pending_download current_user.pending_download = '' current_user.save! else redirect_to root_path, notice: "Unauthorized" endend
Make a partial in view folder name with _downloadFile.js.erb
window.location.href = "<%=@java_url %>"
And of course you will need a route that points to /ajax_download
in routes.rb
get 'ajax_download', to: 'controller#ajax_download'