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.



110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
 
# File 'lib/rails_generator/commands.rb', line 110

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 



233
234
235
236
237
238
 
# File 'lib/rails_generator/commands.rb', line 233

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.



242
243
244
245
246
247
248
249
250
 
# File 'lib/rails_generator/commands.rb', line 242

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

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

Copy a file from source to destination with collision checking.

The file_options hash accepts :chmod and :shebang 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'

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



147
148
149
150
151
152
153
154
155
156
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
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
 
# File 'lib/rails_generator/commands.rb', line 147

def file(relative_source, relative_destination, file_options = {})
  # Determine full paths for source and destination files.
  source      = source_path(relative_source)
  destination = destination_path(relative_destination)

  # Check for and resolve file collisions.
  if File.exists?(destination)

    # Make a choice whether to overwrite the file.  :force and
    # :skip already have their mind made up, but give :ask a shot.
    choice = case options[:collision].to_sym #|| :ask
      when :ask   then force_file_collision?(relative_destination)
      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, 'w') do |df|
    File.open(source) do |sf|
      if block_given?
        df.write(yield(sf))
      else
        line = sf.gets
        if file_options[:shebang]
          df.puts("#!#{file_options[:shebang]}")
          df.puts(line) if line !~ /^#!/
        else
          df.puts(line)
        end
        df.write(sf.read)
      end
    end
  end

  # Optionally change permissions.
  if file_options[:chmod]
    FileUtils.chmod(file_options[:chmod], destination)
  end
end

#readme(*relative_sources) ⇒ Object

Display a README.



253
254
255
256
257
258
 
# File 'lib/rails_generator/commands.rb', line 253

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

#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.



221
222
223
224
225
226
227
228
229
230
231
 
# File 'lib/rails_generator/commands.rb', line 221

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