The base code generator is bare-bones. It sets up the source and destination paths and tells the logger whether to keep its trap shut.

It’s useful for copying files such as stylesheets, images, or javascripts.

For more comprehensive template-based passive code generation with arguments, you’ll want Rails::Generator::NamedBase.

Generators create a manifest of the actions they perform then hand the manifest to a command which replays the actions to do the heavy lifting (such as checking for existing files or creating directories if needed). Create, destroy, and list commands are included. Since a single manifest may be used by any command, creating new generators is as simple as writing some code templates and declaring what you’d like to do with them.

The manifest method must be implemented by subclasses, returning a Rails::Generator::Manifest. The record method is provided as a convenience for manifest creation. Example:

class StylesheetGenerator < Rails::Generator::Base
  def manifest
    record do |m|
      m.directory('public/stylesheets')
      m.file('application.css', 'public/stylesheets/application.css')
    end
  end
end

See Rails::Generator::Commands::Create for a list of methods available to the manifest.

Methods
B
D
M
N
R
S
U
Included Modules
Attributes
[R] args
[R] destination_root
[R] source_root
Class Public methods
new(runtime_args, runtime_options = {})

Source: show 

# File rails/railties/lib/rails_generator/base.rb, line 100
def initialize(runtime_args, runtime_options = {})
  @args = runtime_args
  parse!(@args, runtime_options)

  # Derive source and destination paths.
  @source_root = options[:source] || File.join(spec.path, 'templates')
  if options[:destination]
    @destination_root = options[:destination]
  elsif defined? ::RAILS_ROOT
    @destination_root = ::RAILS_ROOT
  end

  # Silence the logger if requested.
  logger.quiet = options[:quiet]

  # Raise usage error if help is requested.
  usage if options[:help]
end
Instance Public methods
destination_path(relative_destination)

Return the full path from the destination root for the given path. Example for #destination_root = ‘/dest’:

destination_path('some/path.rb') == '/dest/some/path.rb'

Source: show 

# File rails/railties/lib/rails_generator/base.rb, line 152
def destination_path(relative_destination)
  File.join(destination_root, relative_destination)
end
manifest()

Generators must provide a manifest. Use the record method to create a new manifest and record your generator’s actions.

Source: show 

# File rails/railties/lib/rails_generator/base.rb, line 121
def manifest
  raise NotImplementedError, "No manifest for '#{spec.name}' generator."
end
source_path(relative_source)

Return the full path from the source root for the given path. Example for #source_root = ‘/source’:

source_path('some/path.rb') == '/source/some/path.rb'

The given path may include a colon ‘:’ character to indicate that the file belongs to another generator. This notation allows any generator to borrow files from another. Example:

source_path('model:fixture.yml') = '/model/source/path/fixture.yml'

Source: show 

# File rails/railties/lib/rails_generator/base.rb, line 133
def source_path(relative_source)
  # Check whether we're referring to another generator's file.
  name, path = relative_source.split(':', 2)

  # If not, return the full path to our source file.
  if path.nil?
    File.join(source_root, name)

  # Otherwise, ask our referral for the file.
  else
    # FIXME: this is broken, though almost always true.  Others'
    # source_root are not necessarily the templates dir.
    File.join(self.class.lookup(name).path, 'templates', path)
  end
end
Instance Protected methods
banner()

Override with your own usage banner.

Source: show 

# File rails/railties/lib/rails_generator/base.rb, line 163
def banner
  "Usage: #{$0} #{spec.name} [options]"
end
record()

Convenience method for generator subclasses to record a manifest.

Source: show 

# File rails/railties/lib/rails_generator/base.rb, line 158
def record
  Rails::Generator::Manifest.new(self) { |m| yield m }
end
usage_message()

Read USAGE from file in generator base path.

Source: show 

# File rails/railties/lib/rails_generator/base.rb, line 168
def usage_message
  File.read(File.join(spec.path, 'USAGE')) rescue ''
end