如何从表单将user_id获取到Rails中的控制器

Question

this is how I display the user's email in my dropdown

     <%= collection_select(:user, :id, User.all(:conditions => ["company_name=?", $company]), :user_id, :email, :prompt=>'Select a User') %>

this is the parameters being generated:

      Parameters: {"commit"=>"Submit", "utf8"=>"✓", "from_date"=>"December 7, 2011 6:45 AM", "to_date"=>"December 9, 2011 7:45 AM", "user"=>{"user_id"=>"12"}}

Once hitting the submit button it has to display the details with the help of user_id and my index function of the controller looks like this

      def index
      if (!params[:user][:user_id].nil?)
         user_id = params[:user][:user_id]
         else
        user_id = current_user.id
       end

But I get an error like this:

       You have a nil object when you didn't expect it!
       You might have expected an instance of Array.
       The error occurred while evaluating nil.[]

What could be wrong please help thanks in advance

Answer 1

if params[:user] is nil the "params[:user][:user_id].nil raise exeption" need:

unless params[:user].nil? and params[:user][:user_id].nil?
....
else
....
end