Class: XMigra::NewMigrationAdder

Inherits:
SchemaManipulator show all
Defined in:
lib/xmigra/new_migration_adder.rb

Direct Known Subclasses

ImpdeclMigrationAdder

Defined Under Namespace

Classes: IgnoreHandler

Constant Summary collapse

OBSOLETE_VERINC_FILE = 
'version-upgrade-obsolete.yaml'

Constants inherited from SchemaManipulator

SchemaManipulator::ACCESS_SUBDIR, SchemaManipulator::DBINFO_FILE, SchemaManipulator::INDEXES_SUBDIR, SchemaManipulator::PERMISSIONS_FILE, SchemaManipulator::PLUGIN_KEY, SchemaManipulator::STRUCTURE_SUBDIR, SchemaManipulator::VERINC_FILE

Instance Attribute Summary

Attributes inherited from SchemaManipulator

#path, #plugin

Instance Method Summary collapse

Methods inherited from SchemaManipulator

#branch_upgrade_file, #load_plugin!

Constructor Details

#initialize(path) ⇒ NewMigrationAdder

Returns a new instance of NewMigrationAdder.



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# File 'lib/xmigra/new_migration_adder.rb', line 13

def initialize(path)
  super(path)
end

Instance Method Details

#add_migration(summary, options = {}) ⇒ Object

Raises:



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# File 'lib/xmigra/new_migration_adder.rb', line 17

def add_migration(summary, options={})
  struct_dir = @path.join(STRUCTURE_SUBDIR)
  FileUtils.mkdir_p(struct_dir) unless struct_dir.exist?
  
  # Load the head YAML from the structure subdir if it exists or create
  # default empty migration chain
  head_file = struct_dir.join(MigrationChain::HEAD_FILE)
  head_info = if head_file.exist?
    YAML.parse_file(head_file).transform
  else
    {}
  end
  Hash === head_info or raise XMigra::Error, "Invalid #{MigrationChain::HEAD_FILE} format"
  
  if !head_info.empty? && respond_to?(:vcs_production_contents) && (production_head_contents = vcs_production_contents(head_file))
    production_head_info = YAML.load(production_head_contents)
    extending_production = head_info[MigrationChain::LATEST_CHANGE] == production_head_info[MigrationChain::LATEST_CHANGE]
  else
    extending_production = false
  end
  
  new_fpath = struct_dir.join(
    [Date.today.strftime("%Y-%m-%d"), summary].join(' ') + '.yaml'
  )
  raise(XMigra::Error, "Migration file\"#{new_fpath.basename}\" already exists") if new_fpath.exist?
  
  new_data = migration_data(head_info, options)
  
  # Write the head file first, in case a lock is required
  old_head_info = head_info.dup
  head_info[MigrationChain::LATEST_CHANGE] = new_fpath.basename('.yaml').to_s
  File.open(head_file, "w") do |f|
    $xmigra_yamler.dump(head_info, f)
  end
  
  begin
    File.open(new_fpath, "w") do |f|
      $xmigra_yamler.dump(new_data, f)
    end
  rescue
    # Revert the head file to it's previous state
    File.open(head_file, "w") do |f|
      $xmigra_yamler.dump(old_head_info, f)
    end
    
    raise
  end
  
  # Obsolete any existing branch upgrade file
  bufp = branch_upgrade_file
  if bufp.exist?
    warning("#{bufp.relative_path_from(@path)} is obsolete and will be renamed.") if respond_to? :warning
    
    obufp = bufp.dirname.join(OBSOLETE_VERINC_FILE)
    rm_method = respond_to?(:vcs_remove) ? method(:vcs_remove) : FileUtils.method(:rm)
    mv_method = respond_to?(:vcs_move) ? method(:vcs_move) : FileUtils.method(:mv)
    
    rm_method.call(obufp) if obufp.exist?
    mv_method.call(bufp, obufp)
  end
  
  production_chain_extended if extending_production
  
  return new_fpath
end

#each_possible_production_chain_extension_handler {|"on-prod-chain-extended-local"| ... } ⇒ Object

Yield command strings or Proc instances to attempt handling the production-chain-extension event

Strings yielded by this method will be executed using Kernel#system. If this results in ‘nil` (command does not exist), processing will continue through the remaining handlers.

Procs yielded by this method will be executed without any parameters. Unless the invocation returns IgnoreHandler, event processing will terminate after invocation.

Yields:

  • ("on-prod-chain-extended-local") 


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# File 'lib/xmigra/new_migration_adder.rb', line 123

def each_possible_production_chain_extension_handler
  yield "on-prod-chain-extended-local"
  if respond_to?(:vcs_prod_chain_extension_handler) && (vcs_handler = vcs_prod_chain_extension_handler)
    yield vcs_handler.to_s
  end
  yield "on-prod-chain-extended"
  yield Proc.new {
    next unless respond_to? :warning
    warning(<<END_MESSAGE)
This command has extended the production migration chain.

Backing up your development database now may be advantageous in case you need
to accept migrations developed in parallel from upstream before merging your
work back to the mainline.
END_MESSAGE
  }
end

#migration_data(head_info, options = {}) ⇒ Object 



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# File 'lib/xmigra/new_migration_adder.rb', line 83

def migration_data(head_info, options={})
  {}.tap do |data|
    data[Migration::FOLLOWS] = head_info.fetch(MigrationChain::LATEST_CHANGE, Migration::EMPTY_DB)
    data['sql'] = options.fetch(:sql, "<<<<< INSERT SQL HERE >>>>>\n").dup.extend(LiteralYamlStyle)
    data['description'] = options.fetch(:description, "<<<<< DESCRIPTION OF MIGRATION >>>>>").dup.extend(FoldedYamlStyle)
    data[Migration::CHANGES] = options.fetch(:changes, ["<<<<< WHAT THIS MIGRATION CHANGES >>>>>"])
  end
end

#production_chain_extended ⇒ Object

Called when the chain of migrations in the production/master branch is extended with a new migration.

This method calls each_possible_production_chain_extension_handler to generate a chain of handlers.



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# File 'lib/xmigra/new_migration_adder.rb', line 98

def production_chain_extended
  Dir.chdir(self.path) do
    each_possible_production_chain_extension_handler do |handler|
      if handler.kind_of? Proc
        handler_result = handler[]
        break true unless handler_result == IgnoreHandler
      else
        handler_result = system(handler)
        break true unless handler_result.nil?
      end
    end
  end
end