feat: Allow model/id arguments to Processor.

An evolution of f6657c9, as per feedback from @akostadinov in #1215. If
you’re dealing with a deleted record, then you may not have an instance
(and cannot retrieve it from the database, as it doesn’t exist). So, the
Processor class now allows for either an instance, or a model and id.

The model should be the actual class, not the string name of the class.

lib/thinking_sphinx/active_record/callbacks/delete_callbacks.rb

@@ -22,6 +22,6 @@ def after_rollback
   def delete_from_sphinx
     return if ThinkingSphinx::Callbacks.suspended?
 
-    ThinkingSphinx::Processor.new(instance).delete
+    ThinkingSphinx::Processor.new(instance: instance).delete
   end
 end

lib/thinking_sphinx/processor.rb

@@ -1,36 +1,44 @@
 # frozen_string_literal: true
 
 class ThinkingSphinx::Processor
-  def initialize(instance)
+  def initialize(instance: nil, model: nil, id: nil)
+    raise ArgumentError if instance.nil? && (model.nil? || id.nil?)
+
     @instance = instance
+    @model = model || instance.class
+    @id = id
   end
 
   def delete
-    return if instance.new_record?
+    return if instance&.new_record?
 
     indices.each { |index|
       ThinkingSphinx::Deletion.perform(
-        index, instance.public_send(index.primary_key)
+        index, id || instance.public_send(index.primary_key)
       )
     }
   end
 
   def upsert
     real_time_indices.each do |index|
-      ThinkingSphinx::RealTime::Transcriber.new(index).copy instance
+      ThinkingSphinx::RealTime::Transcriber.new(index).copy loaded_instance
     end
   end
 
   private
 
-  attr_reader :instance
+  attr_reader :instance, :model, :id
 
   def indices
     ThinkingSphinx::Configuration.instance.index_set_class.new(
-      :instances => [instance], :classes => [instance.class]
+      :instances => [instance].compact, :classes => [model]
     ).to_a
   end
 
+  def loaded_instance
+    @loaded_instance ||= instance || model.find(id)
+  end
+
   def real_time_indices
     indices.select { |index| index.is_a? ThinkingSphinx::RealTime::Index }
   end

spec/acceptance/real_time_updates_spec.rb

@@ -37,7 +37,7 @@
     expect(Admin::Person.search('Pat').to_a).to be_empty
 
     instance = Admin::Person.find_by(:name => 'Pat')
-    ThinkingSphinx::Processor.new(instance).upsert
+    ThinkingSphinx::Processor.new(instance: instance).upsert
 
     expect(Admin::Person.search('Pat').to_a).to eq([instance])
 
@@ -48,7 +48,7 @@
     expect(Admin::Person.search('Patrick').to_a).to be_empty
 
     instance.reload
-    ThinkingSphinx::Processor.new(instance).upsert
+    ThinkingSphinx::Processor.new(model: Admin::Person, id: instance.id).upsert
 
     expect(Admin::Person.search('Patrick').to_a).to eq([instance])
   end

spec/acceptance/remove_deleted_records_spec.rb

@@ -72,4 +72,28 @@
 
     expect(Bird.search_for_ids('duck')).to be_empty
   end
+
+  it "can use a direct interface for processing records" do
+    pancakes = Article.create! :title => 'Pancakes'
+    index
+    expect(Article.search('pancakes')).not_to be_empty
+
+    Article.connection.execute "DELETE FROM articles WHERE id = #{pancakes.id}"
+    expect(Article.search_for_ids('pancakes')).not_to be_empty
+
+    ThinkingSphinx::Processor.new(instance: pancakes).delete
+    expect(Article.search_for_ids('pancakes')).to be_empty
+  end
+
+  it "can use a direct interface for processing records without an instance" do
+    pancakes = Article.create! :title => 'Pancakes'
+    index
+    expect(Article.search('pancakes')).not_to be_empty
+
+    Article.connection.execute "DELETE FROM articles WHERE id = #{pancakes.id}"
+    expect(Article.search_for_ids('pancakes')).not_to be_empty
+
+    ThinkingSphinx::Processor.new(model: Article, id: pancakes.id).delete
+    expect(Article.search_for_ids('pancakes')).to be_empty
+  end
 end