Class: Rails::Generators::Base

Inherits:
Thor::Group
  • Object
show all
Includes:
Actions, Thor::Actions
Defined in:
railties/lib/rails/generators/base.rb

Direct Known Subclasses

AppBase, NamedBase

Class Method Summary collapse

Methods included from Actions

#add_source, #capify!, #environment, #gem, #gem_group, #generate, #git, #initialize, #initializer, #lib, #rake, #rakefile, #readme, #route, #vendor

Class Method Details

.base_root ⇒ Object

Returns the base root for a common set of generators. This is used to dynamically guess the default source root.



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# File 'railties/lib/rails/generators/base.rb', line 217

def self.base_root
  File.dirname(__FILE__)
end

.class_option(name, options = {}) ⇒ Object

Make class option aware of Rails::Generators.options and Rails::Generators.aliases.



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# File 'railties/lib/rails/generators/base.rb', line 198

def self.class_option(name, options={}) #:nodoc:
  options[:desc]    = "Indicates when to generate #{name.to_s.humanize.downcase}" unless options.key?(:desc)
  options[:aliases] = default_aliases_for_option(name, options)
  options[:default] = default_value_for_option(name, options)
  super(name, options)
end

.default_source_root ⇒ Object

Returns the default source root for a given generator. This is used internally by rails to set its generators source root. If you want to customize your source root, you should use source_root.



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# File 'railties/lib/rails/generators/base.rb', line 208

def self.default_source_root
  return unless base_name && generator_name
  return unless default_generator_root
  path = File.join(default_generator_root, 'templates')
  path if File.exist?(path)
end

.desc(description = nil) ⇒ Object

Tries to get the description from a USAGE file one folder above the source root otherwise uses a default description.



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# File 'railties/lib/rails/generators/base.rb', line 30

def self.desc(description=nil)
  return super if description

  @desc ||= if usage_path
    ERB.new(File.read(usage_path)).result(binding)
  else
    "Description:\n    Create #{base_name.humanize.downcase} files for #{generator_name} generator."
  end
end

.hide! ⇒ Object

Convenience method to hide this generator from the available ones when running rails generator command.



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# File 'railties/lib/rails/generators/base.rb', line 50

def self.hide!
  Rails::Generators.hide_namespace self.namespace
end

.hook_for(*names, &block) ⇒ Object

Invoke a generator based on the value supplied by the user to the given option named “name”. A class option is created when this method is invoked and you can set a hash to customize it.

Examples

module Rails::Generators
  class ControllerGenerator < Base
    hook_for :test_framework, aliases: "-t"
  end
end

The example above will create a test framework option and will invoke a generator based on the user supplied value.

For example, if the user invoke the controller generator as:

rails generate controller Account --test-framework=test_unit

The controller generator will then try to invoke the following generators:

"rails:test_unit", "test_unit:controller", "test_unit"

Notice that “rails:generators:test_unit” could be loaded as well, what Rails looks for is the first and last parts of the namespace. This is what allows any test framework to hook into Rails as long as it provides any of the hooks above.

Options

The first and last part used to find the generator to be invoked are guessed based on class invokes hook_for, as noticed in the example above. This can be customized with two options: :base and :as.

Let’s suppose you are creating a generator that needs to invoke the controller generator from test unit. Your first attempt is:

class AwesomeGenerator < Rails::Generators::Base
  hook_for :test_framework
end

The lookup in this case for test_unit as input is:

"test_unit:awesome", "test_unit"

Which is not the desired lookup. You can change it by providing the :as option:

class AwesomeGenerator < Rails::Generators::Base
  hook_for :test_framework, as: :controller
end

And now it will lookup at:

"test_unit:controller", "test_unit"

Similarly, if you want it to also lookup in the rails namespace, you just need to provide the :base value:

class AwesomeGenerator < Rails::Generators::Base
  hook_for :test_framework, in: :rails, as: :controller
end

And the lookup is exactly the same as previously:

"rails:test_unit", "test_unit:controller", "test_unit"

Switches

All hooks come with switches for user interface. If you do not want to use any test framework, you can do:

rails generate controller Account --skip-test-framework

Or similarly:

rails generate controller Account --no-test-framework

Boolean hooks

In some cases, you may want to provide a boolean hook. For example, webrat developers might want to have webrat available on controller generator. This can be achieved as:

Rails::Generators::ControllerGenerator.hook_for :webrat, type: :boolean

Then, if you want webrat to be invoked, just supply:

rails generate controller Account --webrat

The hooks lookup is similar as above:

"rails:generators:webrat", "webrat:generators:controller", "webrat"

Custom invocations

You can also supply a block to hook_for to customize how the hook is going to be invoked. The block receives two arguments, an instance of the current class and the class to be invoked.

For example, in the resource generator, the controller should be invoked with a pluralized class name. But by default it is invoked with the same name as the resource generator, which is singular. To change this, we can give a block to customize how the controller can be invoked.

hook_for :resource_controller do |instance, controller|
  instance.invoke controller, [ instance.name.pluralize ]
end



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# File 'railties/lib/rails/generators/base.rb', line 163

def self.hook_for(*names, &block)
  options = names.extract_options!
  in_base = options.delete(:in) || base_name
  as_hook = options.delete(:as) || generator_name

  names.each do |name|
    unless class_options.key?(name)
      defaults = if options[:type] == :boolean
        { }
      elsif [true, false].include?(default_value_for_option(name, options))
        { banner: "" }
      else
        { desc: "#{name.to_s.humanize} to be invoked", banner: "NAME" }
      end

      class_option(name, defaults.merge!(options))
    end

    hooks[name] = [ in_base, as_hook ]
    invoke_from_option(name, options, &block)
  end
end

.inherited(base) ⇒ Object

Cache source root and add lib/generators/base/generator/templates to source paths.



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# File 'railties/lib/rails/generators/base.rb', line 223

def self.inherited(base) #:nodoc:
  super

  # Invoke source_root so the default_source_root is set.
  base.source_root

  if base.name && base.name !~ /Base$/
    Rails::Generators.subclasses << base

    Rails::Generators.templates_path.each do |path|
      if base.name.include?('::')
        base.source_paths << File.join(path, base.base_name, base.generator_name)
      else
        base.source_paths << File.join(path, base.generator_name)
      end
    end
  end
end

.namespace(name = nil) ⇒ Object

Convenience method to get the namespace from the class name. It’s the same as Thor default except that the Generator at the end of the class is removed.



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# File 'railties/lib/rails/generators/base.rb', line 43

def self.namespace(name=nil)
  return super if name
  @namespace ||= super.sub(/_generator$/, '').sub(/:generators:/, ':')
end

.remove_hook_for(*names) ⇒ Object

Remove a previously added hook.

remove_hook_for :orm



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# File 'railties/lib/rails/generators/base.rb', line 189

def self.remove_hook_for(*names)
  remove_invocation(*names)

  names.each do |name|
    hooks.delete(name)
  end
end

.source_root(path = nil) ⇒ Object

Returns the source root for this generator using default_source_root as default.



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# File 'railties/lib/rails/generators/base.rb', line 23

def self.source_root(path=nil)
  @_source_root = path if path
  @_source_root ||= default_source_root
end