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
Included Modules
Attributes
[R] args
[R] destination_root
[R] source_root
Public Class methods
new(runtime_args, runtime_options = {})

[ show source ]

     # File railties/lib/rails_generator/base.rb, line 101
101:       def initialize(runtime_args, runtime_options = {})
102:         @args = runtime_args
103:         parse!(@args, runtime_options)
104: 
105:         # Derive source and destination paths.
106:         @source_root = options[:source] || File.join(spec.path, 'templates')
107:         if options[:destination]
108:           @destination_root = options[:destination]
109:         elsif defined? ::RAILS_ROOT
110:           @destination_root = ::RAILS_ROOT
111:         end
112: 
113:         # Silence the logger if requested.
114:         logger.quiet = options[:quiet]
115: 
116:         # Raise usage error if help is requested.
117:         usage if options[:help]
118:       end
Public Instance methods
after_generate()

[ show source ]

     # File railties/lib/rails_generator/base.rb, line 157
157:       def after_generate
158:       end
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'

[ show source ]

     # File railties/lib/rails_generator/base.rb, line 153
153:       def destination_path(relative_destination)
154:         File.join(destination_root, relative_destination)
155:       end
manifest()

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

[ show source ]

     # File railties/lib/rails_generator/base.rb, line 122
122:       def manifest
123:         raise NotImplementedError, "No manifest for '#{spec.name}' generator."
124:       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'

[ show source ]

     # File railties/lib/rails_generator/base.rb, line 134
134:       def source_path(relative_source)
135:         # Check whether we're referring to another generator's file.
136:         name, path = relative_source.split(':', 2)
137: 
138:         # If not, return the full path to our source file.
139:         if path.nil?
140:           File.join(source_root, name)
141: 
142:         # Otherwise, ask our referral for the file.
143:         else
144:           # FIXME: this is broken, though almost always true.  Others'
145:           # source_root are not necessarily the templates dir.
146:           File.join(self.class.lookup(name).path, 'templates', path)
147:         end
148:       end
Protected Instance methods
banner()

Override with your own usage banner.

[ show source ]

     # File railties/lib/rails_generator/base.rb, line 167
167:         def banner
168:           "Usage: #{$0} #{spec.name} [options]"
169:         end
record() {|m| ...}

Convenience method for generator subclasses to record a manifest.

[ show source ]

     # File railties/lib/rails_generator/base.rb, line 162
162:         def record
163:           Rails::Generator::Manifest.new(self) { |m| yield m }
164:         end
usage_message()

Read USAGE from file in generator base path.

[ show source ]

     # File railties/lib/rails_generator/base.rb, line 172
172:         def usage_message
173:           File.read(File.join(spec.path, 'USAGE')) rescue ''
174:         end