Class Rails::Generator::Commands::Create
In: vendor/rails/railties/lib/rails_generator/commands.rb
Parent: Base

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

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.

[Source]

     # File vendor/rails/railties/lib/rails_generator/commands.rb, line 172
172:         def class_collisions(*class_names)
173:           path = class_names.shift
174:           class_names.flatten.each do |class_name|
175:             # Convert to string to allow symbol arguments.
176:             class_name = class_name.to_s
177: 
178:             # Skip empty strings.
179:             next if class_name.strip.empty?
180: 
181:             # Split the class from its module nesting.
182:             nesting = class_name.split('::')
183:             name = nesting.pop
184: 
185:             # Extract the last Module in the nesting.
186:             last = nesting.inject(Object) { |last, nest|
187:               break unless last.const_defined?(nest)
188:               last.const_get(nest)
189:             }
190: 
191:             # If the last Module exists, check whether the given
192:             # class exists and raise a collision if so.
193:             if last and last.const_defined?(name.camelize)
194:               raise_class_collision(class_name)
195:             end
196:           end
197:         end

[Source]

     # File vendor/rails/railties/lib/rails_generator/commands.rb, line 305
305:         def complex_template(relative_source, relative_destination, template_options = {})
306:           options = template_options.dup
307:           options[:assigns] ||= {}
308:           options[:assigns]['template_for_inclusion'] = render_template_part(template_options)
309:           template(relative_source, relative_destination, options)
310:         end

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

[Source]

     # File vendor/rails/railties/lib/rails_generator/commands.rb, line 314
314:         def directory(relative_path)
315:           path = destination_path(relative_path)
316:           if File.exist?(path)
317:             logger.exists relative_path
318:           else
319:             logger.create relative_path
320:             unless options[:pretend]
321:               FileUtils.mkdir_p(path)
322:               # git doesn't require adding the paths, adding the files later will
323:               # automatically do a path add.
324: 
325:               # Subversion doesn't do path adds, so we need to add
326:               # each directory individually.
327:               # So stack up the directory tree and add the paths to
328:               # subversion in order without recursion.
329:               if options[:svn]
330:                 stack = [relative_path]
331:                 until File.dirname(stack.last) == stack.last # dirname('.') == '.'
332:                   stack.push File.dirname(stack.last)
333:                 end
334:                 stack.reverse_each do |rel_path|
335:                   svn_path = destination_path(rel_path)
336:                   system("svn add -N #{svn_path}") unless File.directory?(File.join(svn_path, '.svn'))
337:                 end
338:               end
339:             end
340:           end
341:         end

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.

[Source]

     # File vendor/rails/railties/lib/rails_generator/commands.rb, line 212
212:         def file(relative_source, relative_destination, file_options = {}, &block)
213:           # Determine full paths for source and destination files.
214:           source              = source_path(relative_source)
215:           destination         = destination_path(relative_destination)
216:           destination_exists  = File.exist?(destination)
217: 
218:           # If source and destination are identical then we're done.
219:           if destination_exists and identical?(source, destination, &block)
220:             return logger.identical(relative_destination)
221:           end
222: 
223:           # Check for and resolve file collisions.
224:           if destination_exists
225: 
226:             # Make a choice whether to overwrite the file.  :force and
227:             # :skip already have their mind made up, but give :ask a shot.
228:             choice = case (file_options[:collision] || options[:collision]).to_sym #|| :ask
229:               when :ask   then force_file_collision?(relative_destination, source, destination, file_options, &block)
230:               when :force then :force
231:               when :skip  then :skip
232:               else raise "Invalid collision option: #{options[:collision].inspect}"
233:             end
234: 
235:             # Take action based on our choice.  Bail out if we chose to
236:             # skip the file; otherwise, log our transgression and continue.
237:             case choice
238:               when :force then logger.force(relative_destination)
239:               when :skip  then return(logger.skip(relative_destination))
240:               else raise "Invalid collision choice: #{choice}.inspect"
241:             end
242: 
243:           # File doesn't exist so log its unbesmirched creation.
244:           else
245:             logger.create relative_destination
246:           end
247: 
248:           # If we're pretending, back off now.
249:           return if options[:pretend]
250: 
251:           # Write destination file with optional shebang.  Yield for content
252:           # if block given so templaters may render the source file.  If a
253:           # shebang is requested, replace the existing shebang or insert a
254:           # new one.
255:           File.open(destination, 'wb') do |dest|
256:             dest.write render_file(source, file_options, &block)
257:           end
258: 
259:           # Optionally change permissions.
260:           if file_options[:chmod]
261:             FileUtils.chmod(file_options[:chmod], destination)
262:           end
263: 
264:           # Optionally add file to subversion or git
265:           system("svn add #{destination}") if options[:svn]
266:           system("git add -v #{relative_destination}") if options[:git]
267:         end

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.

[Source]

     # File vendor/rails/railties/lib/rails_generator/commands.rb, line 272
272:         def identical?(source, destination, &block)
273:           return false if File.directory? destination
274:           source      = block_given? ? File.open(source) {|sf| yield(sf)} : IO.read(source)
275:           destination = IO.read(destination)
276:           source == destination
277:         end

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

[Source]

     # File vendor/rails/railties/lib/rails_generator/commands.rb, line 352
352:         def migration_template(relative_source, relative_destination, template_options = {})
353:           migration_directory relative_destination
354:           migration_file_name = template_options[:migration_file_name] || file_name
355:           raise "Another migration is already named #{migration_file_name}: #{existing_migrations(migration_file_name).first}" if migration_exists?(migration_file_name)
356:           template(relative_source, "#{relative_destination}/#{next_migration_string}_#{migration_file_name}.rb", template_options)
357:         end

Display a README.

[Source]

     # File vendor/rails/railties/lib/rails_generator/commands.rb, line 344
344:         def readme(*relative_sources)
345:           relative_sources.flatten.each do |relative_source|
346:             logger.readme relative_source
347:             puts File.read(source_path(relative_source)) unless options[:pretend]
348:           end
349:         end

[Source]

     # File vendor/rails/railties/lib/rails_generator/commands.rb, line 359
359:         def route_resources(*resources)
360:           resource_list = resources.map { |r| r.to_sym.inspect }.join(', ')
361:           sentinel = 'ActionController::Routing::Routes.draw do |map|'
362: 
363:           logger.route "map.resources #{resource_list}"
364:           unless options[:pretend]
365:             gsub_file 'config/routes.rb', /(#{Regexp.escape(sentinel)})/mi do |match|
366:               "#{match}\n  map.resources #{resource_list}\n"
367:             end
368:           end
369:         end

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.

[Source]

     # File vendor/rails/railties/lib/rails_generator/commands.rb, line 293
293:         def template(relative_source, relative_destination, template_options = {})
294:           file(relative_source, relative_destination, template_options) do |file|
295:             # Evaluate any assignments in a temporary, throwaway binding.
296:             vars = template_options[:assigns] || {}
297:             b = binding
298:             vars.each { |k,v| eval "#{k} = vars[:#{k}] || vars['#{k}']", b }
299: 
300:             # Render the source file with the temporary binding.
301:             ERB.new(file.read, nil, '-').result(b)
302:           end
303:         end

[Validate]