fixes #16172 - remove base_class override in template subclasses

On Rails 5.0, the base_class is used during model instantiation to
validate STI relationships as it now casts similarly to Foreman::STI,
causing failures when base_class returns the subclass rather than parent
class.

Removing the overriding of `base_class` in Template subclasses
necessitates changing polymorphic associations to store the base class
in the table's type field rather than the subclass name because the
has_many associations will search by `base_class`. This is recommended
by ActiveRecord when using STI with polymorphic associations:
https://github.com/rails/rails/blob/v5.0.0/activerecord/lib/active_record/associations.rb#L780

app/controllers/templates_controller.rb

@@ -119,7 +119,7 @@ def set_locked(locked)
 
   def load_history
     return unless @template
-    @history = Audit.descending.where(:auditable_id => @template.id, :auditable_type => @template.class, :action => 'update')
+    @history = Audit.descending.where(:auditable_id => @template.id, :auditable_type => @template.class.base_class, :action => 'update')
   end
 
   def action_permission

app/models/provisioning_template.rb

@@ -58,14 +58,6 @@ def self.template_ids_for(hosts)
     ids.uniq
   end
 
-  # we have to override the base_class because polymorphic associations does not detect it correctly, more details at
-  # http://apidock.com/rails/ActiveRecord/Associations/ClassMethods/has_many#1010-Polymorphic-has-many-within-inherited-class-gotcha
-  def self.base_class
-    self
-  end
-  # not sure why but this changes table_name so we set it explicitly
-  self.table_name = 'templates'
-
   def self.template_includes
     super + [:template_kind, :template_combinations => [:hostgroup, :environment]]
   end

app/models/ptable.rb

@@ -41,19 +41,15 @@ class Ptable < Template
     end
   }
 
-  # we have to override the base_class because polymorphic associations does not detect it correctly, more details at
-  # http://apidock.com/rails/ActiveRecord/Associations/ClassMethods/has_many#1010-Polymorphic-has-many-within-inherited-class-gotcha
-  def self.base_class
-    self
-  end
-  # this changes table_name so we set it explicitly
-  self.table_name = 'templates'
-
   def self.template_includes
     super + [:operatingsystems]
   end
 
   def preview_host_collection
     super.where(:managed => true)
   end
+
+  def taxonomy_foreign_conditions
+    { :ptable_id => id }
+  end
 end

app/models/taxable_taxonomy.rb

@@ -11,4 +11,10 @@ class TaxableTaxonomy < ActiveRecord::Base
       where(["taxable_taxonomies.taxable_type NOT IN (?)",types])
     end
   }
+
+  # Always store the base type when associated to an STI class as the has_many scope on the target
+  # class will always default to searching for its base_class.
+  def taxable_type=(class_name)
+    super(class_name.constantize.base_class.to_s)
+  end
 end

app/models/taxonomy.rb

@@ -14,8 +14,8 @@ class Taxonomy < ActiveRecord::Base
   has_many :smart_proxies, :through => :taxable_taxonomies, :source => :taxable, :source_type => 'SmartProxy'
   has_many :compute_resources, :through => :taxable_taxonomies, :source => :taxable, :source_type => 'ComputeResource'
   has_many :media, :through => :taxable_taxonomies, :source => :taxable, :source_type => 'Medium'
-  has_many :provisioning_templates, :through => :taxable_taxonomies, :source => :taxable, :source_type => 'ProvisioningTemplate'
-  has_many :ptables, :through => :taxable_taxonomies, :source => :taxable, :source_type => 'Ptable'
+  has_many :provisioning_templates, -> { where(:type => 'ProvisioningTemplate') }, :through => :taxable_taxonomies, :source => :taxable, :source_type => 'Template'
+  has_many :ptables, -> { where(:type => 'Ptable') }, :through => :taxable_taxonomies, :source => :taxable, :source_type => 'Template'
   has_many :domains, :through => :taxable_taxonomies, :source => :taxable, :source_type => 'Domain'
   has_many :realms, :through => :taxable_taxonomies, :source => :taxable, :source_type => 'Realm'
   has_many :hostgroups, :through => :taxable_taxonomies, :source => :taxable, :source_type => 'Hostgroup'
@@ -145,15 +145,15 @@ def dup
     #  if ignore?("Domain")
     #   Domain.pluck(:id)
     # else
-    #   self.taxable_taxonomies.where(:taxable_type => "Domain").pluck(:taxable_id)
+    #   super()  # self.domain_ids
     # end
     define_method(key) do
       klass = hash_key_to_class(key)
       if ignore?(klass)
         return User.unscoped.except_admin.except_hidden.map(&:id) if klass == "User"
         return klass.constantize.pluck(:id)
       else
-        taxable_taxonomies.where(:taxable_type => klass).pluck(:taxable_id)
+        super()
       end
     end
   end

app/services/tax_host.rb

@@ -26,8 +26,8 @@ def selected_ids
     return @selected_ids if @selected_ids
     ids = default_ids_hash
     #types NOT ignored - get ids that are selected
-    (taxonomy.taxable_taxonomies - taxonomy.ignore_types).group_by { |d| d[:taxable_type] }.map do |k, v|
-      ids["#{k.tableize.singularize}_ids"] = v.map { |i| i[:taxable_id] }
+    hash_keys.each do |col|
+      ids[col] = Array(taxonomy.send(col))
     end
     #types that ARE ignored - get ALL ids for object
     Array(taxonomy.ignore_types).each do |taxonomy_type|

db/migrate/20160719095445_change_template_taxable_taxonomies_type.rb

@@ -0,0 +1,12 @@
+class ChangeTemplateTaxableTaxonomiesType < ActiveRecord::Migration
+  def up
+    known_types = Template.descendants.map(&:to_s)
+    TaxableTaxonomy.where(:taxable_type => known_types).update_all(:taxable_type => 'Template')
+  end
+
+  def down
+    Template.descendants.each do |type|
+      TaxableTaxonomy.where(:taxable_type => 'Template', :taxable_id => type.pluck(:id)).update_all(:taxable_type => type.to_s)
+    end
+  end
+end

db/migrate/20160719100624_change_template_audits_type.rb

@@ -0,0 +1,14 @@
+class ChangeTemplateAuditsType < ActiveRecord::Migration
+  def up
+    known_types = Template.descendants.map(&:to_s)
+    Audit.where(:auditable_type => known_types).update_all(:auditable_type => 'Template')
+    Audit.where(:associated_type => known_types).update_all(:associated_type => 'Template')
+  end
+
+  def down
+    Template.descendants.each do |type|
+      Audit.where(:auditable_type => 'Template', :auditable_id => type.pluck(:id)).update_all(:auditable_type => type.to_s)
+      Audit.where(:associated_type => 'Template', :associated_id => type.pluck(:id)).update_all(:associated_type => type.to_s)
+    end
+  end
+end

db/seeds.rb

@@ -16,7 +16,7 @@ def format_errors(model = nil)
 # additional attributes may be specified for narrowing the scope but note
 # that it can be slow if there's high number of audits for the specified type
 def audit_modified?(type, name, attributes = {})
-  au = Audit.where(:auditable_type => type, :auditable_name => name)
+  au = Audit.where(:auditable_type => type.base_class, :auditable_name => name)
 
   if attributes.present?
     interesting_au = au.select do |audit|

test/fixtures/taxable_taxonomies.yml

@@ -67,12 +67,12 @@ twelve:
 thirteen:
   taxonomy: location1
   taxable: mystring2
-  taxable_type: "ProvisioningTemplate"
+  taxable_type: "Template"
 
 fourteen:
   taxonomy: organization1
   taxable: mystring2
-  taxable_type: "ProvisioningTemplate"
+  taxable_type: "Template"
 
 fifteen:
   taxonomy: location1