Class: PgMorph::Polymorphic

Inherits:
Object
  • Object
show all
Includes:
Naming
Defined in:
lib/pg_morph/polymorphic.rb

Instance Attribute Summary collapse

Instance Method Summary collapse

Methods included from Naming

#after_insert_fun_name, #after_insert_trigger_name, #before_insert_fun_name, #before_insert_trigger_name, #column_name_id, #column_name_type, #proxy_table, #type

Constructor Details

#initialize(parent_table, child_table, options) ⇒ Polymorphic

Returns a new instance of Polymorphic.

Raises:



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# File 'lib/pg_morph/polymorphic.rb', line 7

def initialize(parent_table, child_table, options)
  @parent_table = parent_table
  @child_table = child_table
  @column_name = options[:column]

  raise PgMorph::Exception.new("Column not specified") unless @column_name
end

Instance Attribute Details

#child_table ⇒ Object (readonly)

Returns the value of attribute child_table.



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# File 'lib/pg_morph/polymorphic.rb', line 5

def child_table
  @child_table
end

#column_name ⇒ Object (readonly)

Returns the value of attribute column_name.



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# File 'lib/pg_morph/polymorphic.rb', line 5

def column_name
  @column_name
end

#parent_table ⇒ Object (readonly)

Returns the value of attribute parent_table.



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# File 'lib/pg_morph/polymorphic.rb', line 5

def parent_table
  @parent_table
end

Instance Method Details

#create_after_insert_trigger_fun_sql ⇒ Object 



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# File 'lib/pg_morph/polymorphic.rb', line 45

def create_after_insert_trigger_fun_sql
  fun_name = after_insert_fun_name
  create_trigger_fun(fun_name) do
    %Q{DELETE FROM ONLY #{parent_table} WHERE id = NEW.id;}
  end
end

#create_after_insert_trigger_sql ⇒ Object 



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# File 'lib/pg_morph/polymorphic.rb', line 38

def create_after_insert_trigger_sql
  fun_name = after_insert_fun_name
  trigger_name = after_insert_trigger_name

  create_trigger_sql(parent_table, trigger_name, fun_name, 'AFTER INSERT')
end

#create_before_insert_trigger_fun_sql ⇒ Object 



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# File 'lib/pg_morph/polymorphic.rb', line 25

def create_before_insert_trigger_fun_sql
  before_insert_trigger_content do
    create_trigger_body.strip
  end
end

#create_before_insert_trigger_sql ⇒ Object 



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# File 'lib/pg_morph/polymorphic.rb', line 31

def create_before_insert_trigger_sql
  fun_name = before_insert_fun_name
  trigger_name = before_insert_trigger_name

  create_trigger_sql(parent_table, trigger_name, fun_name, 'BEFORE INSERT')
end

#create_proxy_table_sql ⇒ Object 



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# File 'lib/pg_morph/polymorphic.rb', line 15

def create_proxy_table_sql
  %Q{
  CREATE TABLE #{proxy_table} (
    CHECK (#{column_name_type} = '#{type}'),
    PRIMARY KEY (id),
    FOREIGN KEY (#{column_name_id}) REFERENCES #{child_table}(id)
  ) INHERITS (#{parent_table});
  }
end

#remove_after_insert_trigger_sql ⇒ Object 



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# File 'lib/pg_morph/polymorphic.rb', line 81

def remove_after_insert_trigger_sql
  prosrc = get_function(before_insert_fun_name)
  scan =  prosrc.scan(/(( +(ELS)?IF.+\n)(\s+INSERT INTO.+;\n))/)
  cleared = scan.reject { |x| x[0].match("#{proxy_table}") }

  return '' if cleared.present?
  fun_name = after_insert_fun_name
  trigger_name = after_insert_trigger_name

  drop_trigger_and_fun_sql(trigger_name, parent_table, fun_name)
end

#remove_before_insert_trigger_sql ⇒ Object

Raises:

  • (PG::Error) 


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# File 'lib/pg_morph/polymorphic.rb', line 52

def remove_before_insert_trigger_sql
  trigger_name = before_insert_trigger_name
  fun_name = before_insert_fun_name

  prosrc = get_function(fun_name)
  raise PG::Error.new("There is no such function #{fun_name}()\n") unless prosrc

  scan =  prosrc.scan(/(( +(ELS)?IF.+\n)(\s+INSERT INTO.+;\n))/)
  cleared = scan.reject { |x| x[0].match("#{proxy_table}") }

  if cleared.present?
    cleared[0][0].sub!('ELSIF', 'IF')
    before_insert_trigger_content do
      cleared.map { |m| m[0] }.join('').strip
    end
  else
    drop_trigger_and_fun_sql(trigger_name, parent_table, fun_name)
  end
end

#remove_partition_table ⇒ Object 



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# File 'lib/pg_morph/polymorphic.rb', line 72

def remove_partition_table
  table_empty = ActiveRecord::Base.connection.select_value("SELECT COUNT(*) FROM #{parent_table}_#{child_table}").to_i.zero?
  if table_empty
    %Q{ DROP TABLE IF EXISTS #{proxy_table}; }
  else
    raise PG::Error.new("Partition table #{proxy_table} contains data.\nRemove them before if you want to drop that table.\n")
  end
end