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PORuby on Rails - Accessing data in :has_many => :through association
 

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  1. PORuby on Rails - Accessing data in :has_many => :through association
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    <p>I'm trying to get to grips with this type of association in Rails</p> <p>I have the following three models:</p> <pre><code>User has_many: 'memberships' has_many: groups, :through =&gt; 'memberships' Membership belongs_to: 'user' belongs_to 'group' Group has_many: 'memberships' has_many: 'users', :through =&gt; 'memberships' </code></pre> <p>I have a before_create method which adds a new user to a default user group. </p> <pre><code>user.rb attr_accessor :group_ids before_create :add_user_to_default_group after_save :update_groups def add_user_to_default_group self.group_ids = [1] end #after_save callback to handle group_ids def update_groups unless group_ids.nil? self.memberships.each do |m| m.destroy unless group_ids.include?(m.group_id.to_s) group_ids.delete(m.group_id.to_s) end group_ids.each do |g| self.memberships.create(:group_id =&gt; g) unless g.blank? end reload self.group_ids = nil end end </code></pre> <p>I'm trying to write a test to ensure this is happening correctly. </p> <pre><code>user = User.new user.username = 'testuser' user.email = 'testuser@testdomain.co.uk' user.password = 'testpass' user.password_confirmation = 'testpass' assert user.save assert user.errors.empty? assert !user.memberships.empty? </code></pre> <p>The test passes if I use user.memberships.empty, but not if I use user.groups.empty?. I was under the impression I should be able to access the groups through .groups?</p> <p>How would I test that the user belongs to a default group called 'Active Users'?</p> <p>Any advice would be greatly appreciated. </p> <p>Thanks</p>
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    1. COCan you show us the `before_save` method? And i think you menat `before_create`, 'cause `before_save` will be called with each update.
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