Class: Migrations

Inherits:
Object
  • Object
show all
Defined in:
lib/migrations.rb

Instance Attribute Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(db = nil) ⇒ Migrations

Returns a new instance of Migrations.



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# File 'lib/migrations.rb', line 9

def initialize(db=nil)
  config_file = "config/config.rb"

  if db
    @db = db
  elsif File.exist? config_file
    config = {}
    instance_eval(File.read(config_file)).each do |key, value|
      config[key] = value
    end

    if !config[:db]
      raise "Database connection is not defined in config.rb"
    end

    @db = Sequel.connect("#{config[:db][:adapter]}://#{config[:db][:user]}:#{config[:db][:password]}@#{config[:db][:host]}/#{config[:db][:database]}")
  else
    raise "#{config_file} was not found and no database handle was passed to us."
  end

  @path = 'migrations'
  @verbose = true
end

Instance Attribute Details

#path ⇒ Object

Returns the value of attribute path.



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# File 'lib/migrations.rb', line 6

def path
  @path
end

#verbose ⇒ Object

Returns the value of attribute verbose.



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# File 'lib/migrations.rb', line 7

def verbose
  @verbose
end

Instance Method Details

#applied(n = nil) ⇒ Object 



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# File 'lib/migrations.rb', line 87

def applied(n=nil)
  filesystem, database, all = get_migrations

  applied = []

  database.keys.sort.reverse.each do |migration|
    if (n.nil? or applied.length < n)
      applied.push migration
    end
  end

  applied
end

#apply(version, update_table = true) ⇒ Object 



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# File 'lib/migrations.rb', line 168

def apply(version, update_table=true)
  migration = @path + '/' + version + '.rb'

  load migration

  m = Object::const_get(version).new(@db)

  @verbose and print "Applying: #{version} ... "

  m.up

  @verbose and puts "ok"

  update_table and insert(version)
end

#down(n = nil) ⇒ Object 



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# File 'lib/migrations.rb', line 160

def down(n=nil)
  ensure_migration_table

  applied(n).each do |version|
    revert(version)
  end
end

#ensure_migration_table ⇒ Object 



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# File 'lib/migrations.rb', line 136

def ensure_migration_table
  begin
    table = @db[:migration].map(:version)
  rescue Sequel::DatabaseError => e
    if e.message.match /Table .*? doesn\'t exist/
      @db.create_table :migration do
        primary_key :id
        String :version, :null => false
        DateTime :applied_at
      end
    else
      raise e
    end
  end
end

#generate(name) ⇒ Object 



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# File 'lib/migrations.rb', line 101

def generate(name)
  if !File.exist? @path
    FileUtils.mkdir_p @path
  end

  t = Time.now

  while 1
    t = Time.at(t.to_i + 1)
    class_name = 'M' + t.strftime('%Y%m%d_%H%M%S') + '_' + name.gsub(/[^a-zA-Z0-9_]/i, '')
    migration = "#{@path}/#{class_name}.rb"

    if !File.exist? migration
      break
    end
  end

  File.open(migration,'w') do |f|
    f.write("
require 'migrations/migration'

class #{class_name} < Migration
def up
end

def down
end
end
")
    @verbose and puts "Create new migration: #{migration}"

    true
  end
end

#get_migrations ⇒ Object 



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# File 'lib/migrations.rb', line 33

def get_migrations
  ensure_migration_table

  filesystem = []
  database = {}
  all = []

  Dir.glob(@path + '/*.rb').map do |migration|
    class_name = migration.match(/(M[0-9]{8}_[0-9]{6}_[a-zA-Z0-9_]+)\.rb\z/)[1]

    filesystem.push class_name
    all.push class_name
  end

  @db[:migration].each do |migration|
    database[migration[:version]] = migration[:applied_at]
    if !all.include? migration[:version]
      all.push migration[:version]
    end
  end

  [filesystem,database,all]
end

#insert(version) ⇒ Object 



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# File 'lib/migrations.rb', line 184

def insert(version)
  @db[:migration].insert(:version => version, :applied_at => Time.now)
end

#list ⇒ Object 



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# File 'lib/migrations.rb', line 57

def list
  filesystem, database, all = get_migrations

  list = []

  all.sort.each do |migration|
    list.push({
      :version => migration,
      :applied => database[migration] ? true : false,
      :applied_at => database[migration] ? database[migration] : ''
    })
  end

  list
end

#pending(n = nil) ⇒ Object 



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# File 'lib/migrations.rb', line 73

def pending(n=nil)
  filesystem, database, all = get_migrations

  pending = []

  filesystem.sort.each do |migration|
    if !database.keys.include?(migration) and (n.nil? or pending.length < n)
      pending.push migration
    end
  end

  pending
end

#remove(version) ⇒ Object 



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# File 'lib/migrations.rb', line 208

def remove(version)
  @db[:migration].where('version = ?',version).delete
end

#revert(version, update_table = true) ⇒ Object 



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# File 'lib/migrations.rb', line 188

def revert(version, update_table=true)
  migration = @path + '/' + version + '.rb'

  if !File.exist? migration
    raise "Migration file #{migration} not found."
  end

  load migration

  m = Object::const_get(version).new(@db)

  @verbose and print "Rolling back: #{version} ... "

  m.down

  @verbose and puts "ok"

  update_table and remove(version)
end

#up(n = nil) ⇒ Object 



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# File 'lib/migrations.rb', line 152

def up(n=nil)
  ensure_migration_table

  pending(n).each do |version|
    apply(version)
  end
end