Create is the premier generator command. It copies files, creates directories, renders templates, and more.
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.
# File lib/rails_generator/commands.rb, line 172 def class_collisions(*class_names) path = class_names.shift class_names.flatten.each do |class_name| # Convert to string to allow symbol arguments. class_name = class_name.to_s # Skip empty strings. next if class_name.strip.empty? # Split the class from its module nesting. nesting = class_name.split('::') name = nesting.pop # Hack to limit const_defined? to non-inherited on 1.9. extra = [] extra << false unless Object.method(:const_defined?).arity == 1 # Extract the last Module in the nesting. last = nesting.inject(Object) { |last, nest| break unless last.const_defined?(nest, *extra) last.const_get(nest) } # If the last Module exists, check whether the given # class exists and raise a collision if so. if last and last.const_defined?(name.camelize, *extra) raise_class_collision(class_name) end end end
# File lib/rails_generator/commands.rb, line 309 def complex_template(relative_source, relative_destination, template_options = {}) options = template_options.dup options[:assigns] ||= {} options[:assigns]['template_for_inclusion'] = render_template_part(template_options) template(relative_source, relative_destination, options) end
Create a directory including any missing parent directories. Always skips directories which exist.
# File lib/rails_generator/commands.rb, line 318 def directory(relative_path) path = destination_path(relative_path) if File.exist?(path) logger.exists relative_path else logger.create relative_path unless options[:pretend] FileUtils.mkdir_p(path) # git doesn't require adding the paths, adding the files later will # automatically do a path add. # Subversion doesn't do path adds, so we need to add # each directory individually. # So stack up the directory tree and add the paths to # subversion in order without recursion. if options[:svn] stack = [relative_path] until File.dirname(stack.last) == stack.last # dirname('.') == '.' stack.push File.dirname(stack.last) end stack.reverse_each do |rel_path| svn_path = destination_path(rel_path) system("svn add -N #{svn_path}") unless File.directory?(File.join(svn_path, '.svn')) end end end end 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/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.
# File lib/rails_generator/commands.rb, line 216 def file(relative_source, relative_destination, file_options = {}, &block) # Determine full paths for source and destination files. source = source_path(relative_source) destination = destination_path(relative_destination) destination_exists = File.exist?(destination) # If source and destination are identical then we're done. if destination_exists and identical?(source, destination, &block) return logger.identical(relative_destination) end # Check for and resolve file collisions. if destination_exists # Make a choice whether to overwrite the file. :force and # :skip already have their mind made up, but give :ask a shot. choice = case (file_options[:collision] || options[:collision]).to_sym #|| :ask when :ask then force_file_collision?(relative_destination, source, destination, file_options, &block) when :force then :force when :skip then :skip else raise "Invalid collision option: #{options[:collision].inspect}" end # Take action based on our choice. Bail out if we chose to # skip the file; otherwise, log our transgression and continue. case choice when :force then logger.force(relative_destination) when :skip then return(logger.skip(relative_destination)) else raise "Invalid collision choice: #{choice}.inspect" end # File doesn't exist so log its unbesmirched creation. else logger.create relative_destination end # If we're pretending, back off now. return if options[:pretend] # Write destination file with optional shebang. Yield for content # if block given so templaters may render the source file. If a # shebang is requested, replace the existing shebang or insert a # new one. File.open(destination, 'wb') do |dest| dest.write render_file(source, file_options, &block) end # Optionally change permissions. if file_options[:chmod] FileUtils.chmod(file_options[:chmod], destination) end # Optionally add file to subversion or git system("svn add #{destination}") if options[:svn] system("git add -v #{relative_destination}") if options[:git] 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.
# File lib/rails_generator/commands.rb, line 276 def identical?(source, destination, &block) return false if File.directory? destination source = block_given? ? File.open(source) {|sf| yield(sf)} : IO.read(source) destination = IO.read(destination) source == destination end
When creating a migration, it knows to find the first available file in db/migrate and use the migration.rb template.
# File lib/rails_generator/commands.rb, line 356 def migration_template(relative_source, relative_destination, template_options = {}) migration_directory relative_destination migration_file_name = template_options[:migration_file_name] || file_name raise "Another migration is already named #{migration_file_name}: #{existing_migrations(migration_file_name).first}" if migration_exists?(migration_file_name) template(relative_source, "#{relative_destination}/#{next_migration_string}_#{migration_file_name}.rb", template_options) end
Display a README.
# File lib/rails_generator/commands.rb, line 348 def readme(*relative_sources) relative_sources.flatten.each do |relative_source| logger.readme relative_source puts File.read(source_path(relative_source)) unless options[:pretend] end end
# File lib/rails_generator/commands.rb, line 363 def route_resources(*resources) resource_list = resources.map { |r| r.to_sym.inspect }.join(', ') sentinel = 'ActionController::Routing::Routes.draw do |map|' logger.route "map.resources #{resource_list}" unless options[:pretend] gsub_file 'config/routes.rb', /(#{Regexp.escape(sentinel)})/i do |match| "#{match}\n map.resources #{resource_list}\n" end end 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.
# File lib/rails_generator/commands.rb, line 297 def template(relative_source, relative_destination, template_options = {}) file(relative_source, relative_destination, template_options) do |file| # Evaluate any assignments in a temporary, throwaway binding. vars = template_options[:assigns] || {} b = template_options[:binding] || binding vars.each { |k,v| eval "#{k} = vars[:#{k}] || vars['#{k}']", b } # Render the source file with the temporary binding. ERB.new(file.read, nil, '-').result(b) end end
Generated with the Darkfish Rdoc Generator 2.