Support tenants for taggings (#1000)

* support tenants for taggings

* Make tenant fully optional

* Move section of README to the correct place

Co-authored-by: Heng <heng@reamaze.com>

README.md

@@ -80,6 +80,8 @@ Review the generated migrations then migrate :
 rake db:migrate
 ```
 
+If you do not wish or need to support multi-tenancy, the migration for `add_tenant_to_taggings` is optional and can be discarded safely.
+
 #### For MySql users
 You can circumvent at any time the problem of special characters [issue 623](https://github.com/mbleigh/acts-as-taggable-on/issues/623) by setting in an initializer file:
 
@@ -390,6 +392,27 @@ def remove_owned_tag
 end
 ```
 
+### Tag Tenancy
+
+Tags support multi-tenancy. This is useful for applications where a Tag belongs to a scoped set of models:
+
+```ruby
+class Account < ActiveRecord::Base
+  has_many :photos
+end
+
+class User < ActiveRecord::Base
+  belongs_to :account
+  acts_as_taggable_on :tags
+  acts_as_taggable_tenant :account_id
+end
+
+@user1.tag_list = ["foo", "bar"] # these taggings will automatically have the tenant saved
+@user2.tag_list = ["bar", "baz"]
+
+ActsAsTaggableOn::Tag.for_tenant(@user1.account.id) # returns Tag models for "foo" and "bar", but not "baz"
+```
+
 ### Dirty objects
 
 ```ruby

db/migrate/7_add_tenant_to_taggings.rb

@@ -0,0 +1,16 @@
+if ActiveRecord.gem_version >= Gem::Version.new('5.0')
+  class AddTenantToTaggings < ActiveRecord::Migration[4.2]; end
+else
+  class AddTenantToTaggings < ActiveRecord::Migration; end
+end
+AddTenantToTaggings.class_eval do
+  def self.up
+    add_column :taggings, :tenant, :string, limit: 128
+    add_index :taggings, :tenant unless index_exists? :taggings, :tenant
+  end
+
+  def self.down
+    remove_column :taggings, :tenant
+    remove_index :taggings, :tenant
+  end
+end

lib/acts_as_taggable_on/tag.rb

@@ -55,6 +55,12 @@ def self.for_context(context)
         select("DISTINCT #{ActsAsTaggableOn.tags_table}.*")
     end
 
+    def self.for_tenant(tenant)
+      joins(:taggings).
+        where("#{ActsAsTaggableOn.taggings_table}.tenant = ?", tenant.to_s).
+        select("DISTINCT #{ActsAsTaggableOn.tags_table}.*")
+    end
+
     ### CLASS METHODS:
 
     def self.find_or_create_with_like_by_name(name)

lib/acts_as_taggable_on/taggable.rb

@@ -54,6 +54,23 @@ def acts_as_ordered_taggable_on(*tag_types)
       taggable_on(true, tag_types)
     end
 
+    def acts_as_taggable_tenant(tenant)
+      if taggable?
+        self.tenant_column = tenant
+      else
+        class_attribute :tenant_column
+        self.tenant_column = tenant
+      end
+
+      # each of these add context-specific methods and must be
+      # called on each call of taggable_on
+      include Core
+      include Collection
+      include Cache
+      include Ownership
+      include Related
+    end
+
     private
 
       # Make a model taggable on specified contexts
@@ -78,6 +95,7 @@ def taggable_on(preserve_tag_order, *tag_types)
         self.tag_types = tag_types
         class_attribute :preserve_tag_order
         self.preserve_tag_order = preserve_tag_order
+        class_attribute :tenant_column
 
         class_eval do
           has_many :taggings, as: :taggable, dependent: :destroy, class_name: '::ActsAsTaggableOn::Tagging'

lib/acts_as_taggable_on/taggable/core.rb

@@ -214,6 +214,12 @@ def tagging_contexts
       self.class.tag_types.map(&:to_s) + custom_contexts
     end
 
+    def tenant
+      if self.class.tenant_column
+        read_attribute(self.class.tenant_column)
+      end
+    end
+
     def reload(*args)
       self.class.tag_types.each do |context|
         instance_variable_set("@#{context.to_s.singularize}_list", nil)
@@ -272,7 +278,11 @@ def save_tags
 
         # Create new taggings:
         new_tags.each do |tag|
-          taggings.create!(tag_id: tag.id, context: context.to_s, taggable: self)
+          if tenant
+            taggings.create!(tag_id: tag.id, context: context.to_s, taggable: self, tenant: tenant)
+          else
+            taggings.create!(tag_id: tag.id, context: context.to_s, taggable: self)
+          end
         end
       end
 

lib/acts_as_taggable_on/tagging.rb

@@ -14,6 +14,8 @@ class Tagging < ::ActiveRecord::Base #:nodoc:
     scope :by_contexts, ->(contexts) { where(context: (contexts || DEFAULT_CONTEXT)) }
     scope :by_context, ->(context = DEFAULT_CONTEXT) { by_contexts(context.to_s) }
 
+    scope :by_tenant, ->(tenant) { where(tenant: tenant) }
+
     validates_presence_of :context
     validates_presence_of :tag_id
 

spec/acts_as_taggable_on/tag_spec.rb

@@ -14,7 +14,7 @@
 describe ActsAsTaggableOn::Tag do
   before(:each) do
     @tag = ActsAsTaggableOn::Tag.new
-    @user = TaggableModel.create(name: 'Pablo')
+    @user = TaggableModel.create(name: 'Pablo', tenant_id: 100)
   end
 
 
@@ -70,6 +70,21 @@
     end
   end
 
+  describe 'for tenant' do
+    before(:each) do
+      @user.skill_list.add('ruby')
+      @user.save
+    end
+
+    it 'should return tags for the tenant' do
+      expect(ActsAsTaggableOn::Tag.for_tenant('100').pluck(:name)).to include('ruby')
+    end
+
+    it 'should not return tags for other tenants' do
+      expect(ActsAsTaggableOn::Tag.for_tenant('200').pluck(:name)).to_not include('ruby')
+    end
+  end
+
   describe 'find or create by name' do
     before(:each) do
       @tag.name = 'awesome'

spec/acts_as_taggable_on/taggable_spec.rb

@@ -109,6 +109,10 @@
     expect(@taggable.tag_types).to eq(TaggableModel.tag_types)
   end
 
+  it 'should have tenant column' do
+    expect(TaggableModel.tenant_column).to eq(:tenant_id)
+  end
+
   it 'should have tag_counts_on' do
     expect(TaggableModel.tag_counts_on(:tags)).to be_empty
 
@@ -676,11 +680,11 @@
     end
 
     it 'should return all column names joined for TaggableModel GROUP clause' do
-      expect(@taggable.grouped_column_names_for(TaggableModel)).to eq('taggable_models.id, taggable_models.name, taggable_models.type')
+      expect(@taggable.grouped_column_names_for(TaggableModel)).to eq('taggable_models.id, taggable_models.name, taggable_models.type, taggable_models.tenant_id')
     end
 
     it 'should return all column names joined for NonStandardIdTaggableModel GROUP clause' do
-      expect(@taggable.grouped_column_names_for(TaggableModel)).to eq("taggable_models.#{TaggableModel.primary_key}, taggable_models.name, taggable_models.type")
+      expect(@taggable.grouped_column_names_for(TaggableModel)).to eq("taggable_models.#{TaggableModel.primary_key}, taggable_models.name, taggable_models.type, taggable_models.tenant_id")
     end
   end
 

spec/acts_as_taggable_on/tagging_spec.rb

@@ -77,12 +77,14 @@
       @tagging.tag = ActsAsTaggableOn::Tag.create(name: "Physics")
       @tagging.tagger = @tagger
       @tagging.context = 'Science'
+      @tagging.tenant = 'account1'
       @tagging.save
 
       @tagging_2.taggable = TaggableModel.create(name: "Satellites")
       @tagging_2.tag = ActsAsTaggableOn::Tag.create(name: "Technology")
       @tagging_2.tagger = @tagger_2
       @tagging_2.context = 'Science'
+      @tagging_2.tenant = 'account1'
       @tagging_2.save
 
       @tagging_3.taggable = TaggableModel.create(name: "Satellites")
@@ -114,6 +116,14 @@
       end
     end
 
+    describe '.by_tenant' do
+      it "should find taggings by tenant" do
+        expect(ActsAsTaggableOn::Tagging.by_tenant('account1').length).to eq(2);
+        expect(ActsAsTaggableOn::Tagging.by_tenant('account1').first).to eq(@tagging);
+        expect(ActsAsTaggableOn::Tagging.by_tenant('account1').second).to eq(@tagging_2);
+      end
+    end
+
     describe '.not_owned' do
       before do
         @tagging_4 = ActsAsTaggableOn::Tagging.new

spec/internal/app/models/taggable_model.rb

@@ -3,6 +3,8 @@ class TaggableModel < ActiveRecord::Base
   acts_as_taggable_on :languages
   acts_as_taggable_on :skills
   acts_as_taggable_on :needs, :offerings
+  acts_as_taggable_tenant :tenant_id
+
   has_many :untaggable_models
 
   attr_reader :tag_list_submethod_called

spec/internal/db/schema.rb

@@ -21,6 +21,8 @@
     # length for MyISAM table type: http://bit.ly/vgW2Ql
     t.string :context, limit: 128
 
+    t.string :tenant , limit: 128
+
     t.datetime :created_at
   end
   add_index ActsAsTaggableOn.taggings_table,
@@ -34,6 +36,7 @@
   create_table :taggable_models, force: true do |t|
     t.column :name, :string
     t.column :type, :string
+    t.column :tenant_id, :integer
   end
 
   create_table :columns_override_models, force: true do |t|