Create is the premier generator command. It copies files, creates directories, renders templates, and more.

Methods
Constants
SYNONYM_LOOKUP_URI = "http://wordnet.princeton.edu/perl/webwn?s=%s"
Public Instance methods
class_collisions(*class_names)

Check whether the given class names are already taken by Ruby or Rails. In the future, expand to check other namespaces such as the rest of the user‘s app.

[ show source ]

     # File railties/lib/rails_generator/commands.rb, line 173
173:         def class_collisions(*class_names)
174:           path = class_names.shift
175:           class_names.flatten.each do |class_name|
176:             # Convert to string to allow symbol arguments.
177:             class_name = class_name.to_s
178: 
179:             # Skip empty strings.
180:             next if class_name.strip.empty?
181: 
182:             # Split the class from its module nesting.
183:             nesting = class_name.split('::')
184:             name = nesting.pop
185: 
186:             # Hack to limit const_defined? to non-inherited on 1.9.
187:             extra = []
188:             extra << false unless Object.method(:const_defined?).arity == 1
189: 
190:             # Extract the last Module in the nesting.
191:             last = nesting.inject(Object) { |last, nest|
192:               break unless last.const_defined?(nest, *extra)
193:               last.const_get(nest)
194:             }
195: 
196:             # If the last Module exists, check whether the given
197:             # class exists and raise a collision if so.
198:             if last and last.const_defined?(name.camelize, *extra)
199:               raise_class_collision(class_name)
200:             end
201:           end
202:         end
complex_template(relative_source, relative_destination, template_options = {})

[ show source ]

     # File railties/lib/rails_generator/commands.rb, line 310
310:         def complex_template(relative_source, relative_destination, template_options = {})
311:           options = template_options.dup
312:           options[:assigns] ||= {}
313:           options[:assigns]['template_for_inclusion'] = render_template_part(template_options)
314:           template(relative_source, relative_destination, options)
315:         end
directory(relative_path)

Create a directory including any missing parent directories. Always skips directories which exist.

[ show source ]

     # File railties/lib/rails_generator/commands.rb, line 319
319:         def directory(relative_path)
320:           path = destination_path(relative_path)
321:           if File.exist?(path)
322:             logger.exists relative_path
323:           else
324:             logger.create relative_path
325:             unless options[:pretend]
326:               FileUtils.mkdir_p(path)
327:               # git doesn't require adding the paths, adding the files later will
328:               # automatically do a path add.
329: 
330:               # Subversion doesn't do path adds, so we need to add
331:               # each directory individually.
332:               # So stack up the directory tree and add the paths to
333:               # subversion in order without recursion.
334:               if options[:svn]
335:                 stack = [relative_path]
336:                 until File.dirname(stack.last) == stack.last # dirname('.') == '.'
337:                   stack.push File.dirname(stack.last)
338:                 end
339:                 stack.reverse_each do |rel_path|
340:                   svn_path = destination_path(rel_path)
341:                   system("svn add -N #{svn_path}") unless File.directory?(File.join(svn_path, '.svn'))
342:                 end
343:               end
344:             end
345:           end
346:         end
file(relative_source, relative_destination, file_options = {}, &block)

Copy a file from source to destination with collision checking.

The file_options hash accepts :chmod and :shebang and :collision options. :chmod sets the permissions of the destination file: 

  file 'config/empty.log', 'log/test.log', :chmod => 0664

:shebang sets the #!/usr/bin/ruby line for scripts 

  file 'bin/generate.rb', 'script/generate', :chmod => 0755, :shebang => '/usr/bin/env ruby'

:collision sets the collision option only for the destination file: 

  file 'settings/server.yml', 'config/server.yml', :collision => :skip

Collisions are handled by checking whether the destination file exists and either skipping the file, forcing overwrite, or asking the user what to do.

[ show source ]

     # File railties/lib/rails_generator/commands.rb, line 217
217:         def file(relative_source, relative_destination, file_options = {}, &block)
218:           # Determine full paths for source and destination files.
219:           source              = source_path(relative_source)
220:           destination         = destination_path(relative_destination)
221:           destination_exists  = File.exist?(destination)
222: 
223:           # If source and destination are identical then we're done.
224:           if destination_exists and identical?(source, destination, &block)
225:             return logger.identical(relative_destination)
226:           end
227: 
228:           # Check for and resolve file collisions.
229:           if destination_exists
230: 
231:             # Make a choice whether to overwrite the file.  :force and
232:             # :skip already have their mind made up, but give :ask a shot.
233:             choice = case (file_options[:collision] || options[:collision]).to_sym #|| :ask
234:               when :ask   then force_file_collision?(relative_destination, source, destination, file_options, &block)
235:               when :force then :force
236:               when :skip  then :skip
237:               else raise "Invalid collision option: #{options[:collision].inspect}"
238:             end
239: 
240:             # Take action based on our choice.  Bail out if we chose to
241:             # skip the file; otherwise, log our transgression and continue.
242:             case choice
243:               when :force then logger.force(relative_destination)
244:               when :skip  then return(logger.skip(relative_destination))
245:               else raise "Invalid collision choice: #{choice}.inspect"
246:             end
247: 
248:           # File doesn't exist so log its unbesmirched creation.
249:           else
250:             logger.create relative_destination
251:           end
252: 
253:           # If we're pretending, back off now.
254:           return if options[:pretend]
255: 
256:           # Write destination file with optional shebang.  Yield for content
257:           # if block given so templaters may render the source file.  If a
258:           # shebang is requested, replace the existing shebang or insert a
259:           # new one.
260:           File.open(destination, 'wb') do |dest|
261:             dest.write render_file(source, file_options, &block)
262:           end
263: 
264:           # Optionally change permissions.
265:           if file_options[:chmod]
266:             FileUtils.chmod(file_options[:chmod], destination)
267:           end
268: 
269:           # Optionally add file to subversion or git
270:           system("svn add #{destination}") if options[:svn]
271:           system("git add -v #{relative_destination}") if options[:git]
272:         end
identical?(source, destination) {|sf| ...}

Checks if the source and the destination file are identical. If passed a block then the source file is a template that needs to first be evaluated before being compared to the destination.

[ show source ]

     # File railties/lib/rails_generator/commands.rb, line 277
277:         def identical?(source, destination, &block)
278:           return false if File.directory? destination
279:           source      = block_given? ? File.open(source) {|sf| yield(sf)} : IO.read(source)
280:           destination = IO.read(destination)
281:           source == destination
282:         end
migration_template(relative_source, relative_destination, template_options = {})

When creating a migration, it knows to find the first available file in db/migrate and use the migration.rb template.

[ show source ]

     # File railties/lib/rails_generator/commands.rb, line 357
357:         def migration_template(relative_source, relative_destination, template_options = {})
358:           migration_directory relative_destination
359:           migration_file_name = template_options[:migration_file_name] || file_name
360:           raise "Another migration is already named #{migration_file_name}: #{existing_migrations(migration_file_name).first}" if migration_exists?(migration_file_name)
361:           template(relative_source, "#{relative_destination}/#{next_migration_string}_#{migration_file_name}.rb", template_options)
362:         end
readme(*relative_sources)

Display a README.

[ show source ]

     # File railties/lib/rails_generator/commands.rb, line 349
349:         def readme(*relative_sources)
350:           relative_sources.flatten.each do |relative_source|
351:             logger.readme relative_source
352:             puts File.read(source_path(relative_source)) unless options[:pretend]
353:           end
354:         end
route_resources(*resources)

[ show source ]

     # File railties/lib/rails_generator/commands.rb, line 364
364:         def route_resources(*resources)
365:           resource_list = resources.map { |r| r.to_sym.inspect }.join(', ')
366:           sentinel = 'ActionController::Routing::Routes.draw do |map|'
367: 
368:           logger.route "map.resources #{resource_list}"
369:           unless options[:pretend]
370:             gsub_file 'config/routes.rb', /(#{Regexp.escape(sentinel)})/mi do |match|
371:               "#{match}\n  map.resources #{resource_list}\n"
372:             end
373:           end
374:         end
template(relative_source, relative_destination, template_options = {})

Generate a file for a Rails application using an ERuby template. Looks up and evaluates a template by name and writes the result.

The ERB template uses explicit trim mode to best control the proliferation of whitespace in generated code. <%- trims leading whitespace; -%> trims trailing whitespace including one newline.

A hash of template options may be passed as the last argument. The options accepted by the file are accepted as well as :assigns, a hash of variable bindings. Example: 

  template 'foo', 'bar', :assigns => { :action => 'view' }

Template is implemented in terms of file. It calls file with a block which takes a file handle and returns its rendered contents.

[ show source ]

     # File railties/lib/rails_generator/commands.rb, line 298
298:         def template(relative_source, relative_destination, template_options = {})
299:           file(relative_source, relative_destination, template_options) do |file|
300:             # Evaluate any assignments in a temporary, throwaway binding.
301:             vars = template_options[:assigns] || {}
302:             b = template_options[:binding] || binding
303:             vars.each { |k,v| eval "#{k} = vars[:#{k}] || vars['#{k}']", b }
304: 
305:             # Render the source file with the temporary binding.
306:             ERB.new(file.read, nil, '-').result(b)
307:           end
308:         end