Passing extra parameter through a link

Question

In my application I have user and activities tables and the user has three activities.

I have a home page with three buttons on it. If the user presses button 1, I want to navigate to the activities index page and set the attribute activity_type to = 1. If the user presses button 2, I want to navigate to the activities index page and set the activity_type to 2, etc.

Right now I have:

<%= link_to 'Personal Activity', user_activities_path(:user_id => current_user.id, :activity_type => 1) %>
<%= link_to 'Physical Activity', user_activities_path(:user_id => current_user.id, :activity_type => 2) %>
<%= link_to 'Community Activity', user_activities_path(:user_id => current_user.id, :activity_type => 3) %>

In my activities controller index method I have:

class ActivitiesController < ApplicationController

  def index
    @activities = Activity.all

    @activity_type = params[:activity_type]

    case @activity_type
    when 1
      $activity_type_var = 1
    when 2
      $activity_type_var = 2
    else
      $activity_type_var = 3
    end
  end

I have this in my activities/index.html.erb:

 <% if $activity_type_var == 1 %>
        <%= "Personal Activity" %>

<% elsif $activity_type_var == 2 %>
        <%= "Physical Activity" %> 

<% elsif $activity_type_var == 3 %>
        <%= "Community Activity" %> 
<% else %>
        <%= "NOT WORKING" %>      
<% end %>

No matter what link I choose from the home page, "Community Activity" shows on the view, meaning the activity_type always seems to be 3. I don't think it is recognizing the activity_type I am passing through the link in the home page.

Is there a different way to do this, or am I doing this incorrectly?

Answer 1

You are passing an integer in your link (:activity_type => 1), but everything is sent as a string into Rails. So params[:activity_type] is a string, not an integer (ie. "1" not 1). So when you do your case statement you are trying to compare "1" to 1, 2, or else. And since "1" != 1" (or 2) your case is always going to use the default case and set $activity_type_var to 3.

Don't use global variables. An instance variable would be just fine.