Module: XMigra::ReversionScriptBuilding

Included in:
SchemaUpdater
Defined in:
lib/xmigra/reversion_script_building.rb

Instance Method Summary collapse

Instance Method Details

#reversion_script ⇒ Object 



21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
 
# File 'lib/xmigra/reversion_script_building.rb', line 21

def reversion_script
  return nil if reversions.empty?
  
  usage_note = [
    "Run the reversion scripts below (separated by -- ======= -- dividers) in",
    "the order given to revert changes as far as desired.  Migrations should",
    "always be reverted in the order given in this file.  If any migration is",
    "not reverted and one further down this file is, XMigra will no longer be",
    "able to update the database schema.\n",
    "The query:",
    "",
    "    SELECT * FROM xmigra.last_applied_migrations ORDER BY \"RevertOrder\";",
    "",
    "lists the migrations applied by the last upgrade script run against this",
    "database.\n",
  ].collect {|l| '-- ' + l + "\n"}.join('')
  
  "".tap do |result|
    result << usage_note + "========================================\n"
    result << reversions.join("-- ================================== --\n")
    
    Plugin.active.amend_composed_sql(result) if Plugin.active
  end
end

#reversions ⇒ Object

This module is intended to be included into XMigra::SchemaUpdater



8
9
10
11
12
13
14
15
16
17
18
19
 
# File 'lib/xmigra/reversion_script_building.rb', line 8

def reversions
  if @reversions.nil?
    @reversions = []
    migrations.reverse_each do |m|
      reversion = m.reversion
      break unless reversion
      @reversions << reversion
    end
  end
  
  return @reversions if @reversions
end