Class: Rails::Generator::Commands::Create

Inherits:
Base show all
Defined in:
lib/rails_generator/commands.rb

Overview

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

Direct Known Subclasses

Update

Instance Attribute Summary

Attributes inherited from Base

#args, #destination_root, #source_root

Instance Method Summary collapse

Methods inherited from Base

#dependency, #invoke!

Methods inherited from Base

#destination_path, #initialize, #manifest, #source_path

Constructor Details

This class inherits a constructor from Rails::Generator::Base

Instance Method Details

#class_collisions(*class_names) ⇒ Object

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.



157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
 
# File 'lib/rails_generator/commands.rb', line 157

def class_collisions(*class_names)
  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

    # Extract the last Module in the nesting.
    last = nesting.inject(Object) { |last, nest|
      break unless last.const_defined?(nest)
      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)
      raise_class_collision(class_name)
    end
  end
end

#complex_template(relative_source, relative_destination, template_options = {}) ⇒ Object 



288
289
290
291
292
293
 
# File 'lib/rails_generator/commands.rb', line 288

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

#directory(relative_path) ⇒ Object

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



297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
 
# File 'lib/rails_generator/commands.rb', line 297

def directory(relative_path)
         path = destination_path(relative_path)
         if File.exists?(path)
           logger.exists relative_path
         else
           logger.create relative_path
    unless options[:pretend]
      FileUtils.mkdir_p(path)
      
      # 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

#file(relative_source, relative_destination, file_options = {}, &block) ⇒ Object

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.



196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
 
# File 'lib/rails_generator/commands.rb', line 196

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.exists?(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
  system("svn add #{destination}") if options[:svn]
end

#identical?(source, destination, &block) ⇒ Boolean

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.

Returns:

  • (Boolean) 


255
256
257
258
259
260
 
# File 'lib/rails_generator/commands.rb', line 255

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

#migration_template(relative_source, relative_destination, template_options = {}) ⇒ Object

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



333
334
335
336
337
338
 
# File 'lib/rails_generator/commands.rb', line 333

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

#readme(*relative_sources) ⇒ Object

Display a README.



325
326
327
328
329
330
 
# File 'lib/rails_generator/commands.rb', line 325

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

#route_resources(*resources) ⇒ Object 



340
341
342
343
344
345
346
347
348
349
350
 
# File 'lib/rails_generator/commands.rb', line 340

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)})/mi do |match|
      "#{match}\n  map.resources #{resource_list}\n"
    end
  end
end

#template(relative_source, relative_destination, template_options = {}) ⇒ Object

Generate a file for a Rails application using an ERuby template. Looks up and evalutes 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.



276
277
278
279
280
281
282
283
284
285
286
 
# File 'lib/rails_generator/commands.rb', line 276

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 = 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