ActiveAdmin Custom Pages

Question

I'm trying to pass a variable from my controller to a custom activeadmin page but I can't seem to figure it out.

I basically have a form that uploads a file and it parses it. If it reaches an error, it throws one and redirects to the custom page.

class ToolController < ApiController
def import
    begin
        Schedule.Parse(data)
    rescue MissingDependencyError => e
        @dependencies = "test"
        redirect_to admin_import_path({}.merge(flash_error: "Missing Dependencies", dependency_error: true, :locals => { :m => e.object }))
    end
end

class MissingDependencyError < StandardError
    attr_reader :object

    def initialize(object)
        @object = object
    end
end

ActiveAdmin.register_page "Import" do |lab|
    menu false
    content do
        @dependencies    
    end
end

@dependencies comes back as nil -> why?

I can pass it through the params hash but that's not the right way.

Answer 1

Instance variables are not available after a redirect_to ... the redirect_to creates a new controller instance and all the instance variables of the previous controller object are gone.

Instead of the params hash, you can use the sessions hash

session[:dependencies] = "test"

and

content do
  session[:dependencies]
end