aboutsummaryrefslogtreecommitdiffstats
path: root/railties/lib/rails/generators.rb
blob: a7da92168dda322dfb07b09a1b3738e987f6befa (plain) (blame)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
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
135
136
137
138
139
140
141
142
143
144
145
146
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
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
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
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
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
activesupport_path = File.expand_path('../../../../activesupport/lib', __FILE__)
$:.unshift(activesupport_path) if File.directory?(activesupport_path) && !$:.include?(activesupport_path)

require 'thor/group'

require 'active_support'
require 'active_support/core_ext/object/blank'
require 'active_support/core_ext/kernel/singleton_class'
require 'active_support/core_ext/array/extract_options'
require 'active_support/core_ext/hash/deep_merge'
require 'active_support/core_ext/module/attribute_accessors'
require 'active_support/core_ext/string/inflections'

module Rails
  module Generators
    autoload :Actions,         'rails/generators/actions'
    autoload :ActiveModel,     'rails/generators/active_model'
    autoload :Base,            'rails/generators/base'
    autoload :Migration,       'rails/generators/migration'
    autoload :NamedBase,       'rails/generators/named_base'
    autoload :ResourceHelpers, 'rails/generators/resource_helpers'
    autoload :TestCase,        'rails/generators/test_case'

    mattr_accessor :namespace

    DEFAULT_ALIASES = {
      rails: {
        actions: '-a',
        orm: '-o',
        javascripts: '-j',
        javascript_engine: '-je',
        resource_controller: '-c',
        scaffold_controller: '-c',
        stylesheets: '-y',
        stylesheet_engine: '-se',
        template_engine: '-e',
        test_framework: '-t'
      },

      test_unit: {
        fixture_replacement: '-r',
      }
    }

    DEFAULT_OPTIONS = {
      rails: {
        assets: true,
        force_plural: false,
        helper: true,
        integration_tool: nil,
        javascripts: true,
        javascript_engine: :js,
        orm: false,
        resource_controller: :controller,
        resource_route: true,
        scaffold_controller: :scaffold_controller,
        stylesheets: true,
        stylesheet_engine: :css,
        test_framework: false,
        template_engine: :erb
      }
    }

    def self.configure!(config) #:nodoc:
      no_color! unless config.colorize_logging
      aliases.deep_merge! config.aliases
      options.deep_merge! config.options
      fallbacks.merge! config.fallbacks
      templates_path.concat config.templates
      templates_path.uniq!
      hide_namespaces(*config.hidden_namespaces)
    end

    def self.templates_path #:nodoc:
      @templates_path ||= []
    end

    def self.aliases #:nodoc:
      @aliases ||= DEFAULT_ALIASES.dup
    end

    def self.options #:nodoc:
      @options ||= DEFAULT_OPTIONS.dup
    end

    # Hold configured generators fallbacks. If a plugin developer wants a
    # generator group to fallback to another group in case of missing generators,
    # they can add a fallback.
    #
    # For example, shoulda is considered a test_framework and is an extension
    # of test_unit. However, most part of shoulda generators are similar to
    # test_unit ones.
    #
    # Shoulda then can tell generators to search for test_unit generators when
    # some of them are not available by adding a fallback:
    #
    #   Rails::Generators.fallbacks[:shoulda] = :test_unit
    def self.fallbacks
      @fallbacks ||= {}
    end

    # Remove the color from output.
    def self.no_color!
      Thor::Base.shell = Thor::Shell::Basic
    end

    # Track all generators subclasses.
    def self.subclasses
      @subclasses ||= []
    end

    # Rails finds namespaces similar to thor, it only adds one rule:
    #
    # Generators names must end with "_generator.rb". This is required because Rails
    # looks in load paths and loads the generator just before it's going to be used.
    #
    #   find_by_namespace :webrat, :rails, :integration
    #
    # Will search for the following generators:
    #
    #   "rails:webrat", "webrat:integration", "webrat"
    #
    # Notice that "rails:generators:webrat" could be loaded as well, what
    # Rails looks for is the first and last parts of the namespace.
    def self.find_by_namespace(name, base=nil, context=nil) #:nodoc:
      lookups = []
      lookups << "#{base}:#{name}"    if base
      lookups << "#{name}:#{context}" if context

      unless base || context
        unless name.to_s.include?(?:)
          lookups << "#{name}:#{name}"
          lookups << "rails:#{name}"
        end
        lookups << "#{name}"
      end

      lookup(lookups)

      namespaces = Hash[subclasses.map { |klass| [klass.namespace, klass] }]

      lookups.each do |namespace|
        klass = namespaces[namespace]
        return klass if klass
      end

      invoke_fallbacks_for(name, base) || invoke_fallbacks_for(context, name)
    end

    # Receives a namespace, arguments and the behavior to invoke the generator.
    # It's used as the default entry point for generate, destroy and update
    # commands.
    def self.invoke(namespace, args=ARGV, config={})
      names = namespace.to_s.split(':')
      if klass = find_by_namespace(names.pop, names.any? && names.join(':'))
        args << "--help" if args.empty? && klass.arguments.any?(&:required?)
        klass.start(args, config)
      else
        options     = sorted_groups.flat_map(&:last)
        suggestions = options.sort_by {|suggested| levenshtein_distance(namespace.to_s, suggested) }.first(3)
        msg =  "Could not find generator '#{namespace}'. "
        msg << "Maybe you meant #{ suggestions.map {|s| "'#{s}'"}.to_sentence(last_word_connector: " or ") }\n"
        msg << "Run `rails generate --help` for more options."
        puts msg
      end
    end

    # Returns an array of generator namespaces that are hidden.
    # Generator namespaces may be hidden for a variety of reasons.
    # Some are aliased such as "rails:migration" and can be
    # invoked with the shorter "migration", others are private to other generators
    # such as "css:scaffold".
    def self.hidden_namespaces
      @hidden_namespaces ||= begin
        orm      = options[:rails][:orm]
        test     = options[:rails][:test_framework]
        template = options[:rails][:template_engine]
        css      = options[:rails][:stylesheet_engine]

        [
          "rails",
          "resource_route",
          "#{orm}:migration",
          "#{orm}:model",
          "#{test}:controller",
          "#{test}:helper",
          "#{test}:integration",
          "#{test}:mailer",
          "#{test}:model",
          "#{test}:scaffold",
          "#{test}:view",
          "#{template}:controller",
          "#{template}:scaffold",
          "#{template}:mailer",
          "#{css}:scaffold",
          "#{css}:assets",
          "css:assets",
          "css:scaffold"
        ]
      end
    end

    class << self
      def hide_namespaces(*namespaces)
        hidden_namespaces.concat(namespaces)
      end
      alias hide_namespace hide_namespaces
    end

    # Show help message with available generators.
    def self.help(command = 'generate')
      puts "Usage: rails #{command} GENERATOR [args] [options]"
      puts
      puts "General options:"
      puts "  -h, [--help]     # Print generator's options and usage"
      puts "  -p, [--pretend]  # Run but do not make any changes"
      puts "  -f, [--force]    # Overwrite files that already exist"
      puts "  -s, [--skip]     # Skip files that already exist"
      puts "  -q, [--quiet]    # Suppress status output"
      puts
      puts "Please choose a generator below."
      puts

      print_generators
    end

    def self.public_namespaces
      lookup!
      subclasses.map(&:namespace)
    end

    def self.print_generators
      sorted_groups.each { |b, n| print_list(b, n) }
    end

    def self.sorted_groups
      namespaces = public_namespaces
      namespaces.sort!
      groups = Hash.new { |h,k| h[k] = [] }
      namespaces.each do |namespace|
        base = namespace.split(':').first
        groups[base] << namespace
      end
      rails = groups.delete("rails")
      rails.map! { |n| n.sub(/^rails:/, '') }
      rails.delete("app")
      rails.delete("plugin")

      hidden_namespaces.each { |n| groups.delete(n.to_s) }

      [["rails", rails]] + groups.sort.to_a
    end

    protected

      # This code is based directly on the Text gem implementation
      # Returns a value representing the "cost" of transforming str1 into str2
      def self.levenshtein_distance str1, str2
        s = str1
        t = str2
        n = s.length
        m = t.length

        return m if (0 == n)
        return n if (0 == m)

        d = (0..m).to_a
        x = nil

        # avoid duplicating an enumerable object in the loop
        str2_codepoint_enumerable = str2.each_codepoint

        str1.each_codepoint.with_index do |char1, i|
          e = i+1

          str2_codepoint_enumerable.with_index do |char2, j|
            cost = (char1 == char2) ? 0 : 1
            x = [
                 d[j+1] + 1, # insertion
                 e + 1,      # deletion
                 d[j] + cost # substitution
                ].min
            d[j] = e
            e = x
          end

          d[m] = x
        end

        x
      end

      # Prints a list of generators.
      def self.print_list(base, namespaces) #:nodoc:
        namespaces = namespaces.reject do |n|
          hidden_namespaces.include?(n)
        end

        return if namespaces.empty?
        puts "#{base.camelize}:"

        namespaces.each do |namespace|
          puts("  #{namespace}")
        end

        puts
      end

      # Try fallbacks for the given base.
      def self.invoke_fallbacks_for(name, base) #:nodoc:
        return nil unless base && fallbacks[base.to_sym]
        invoked_fallbacks = []

        Array(fallbacks[base.to_sym]).each do |fallback|
          next if invoked_fallbacks.include?(fallback)
          invoked_fallbacks << fallback

          klass = find_by_namespace(name, fallback)
          return klass if klass
        end

        nil
      end

      # Receives namespaces in an array and tries to find matching generators
      # in the load path.
      def self.lookup(namespaces) #:nodoc:
        paths = namespaces_to_paths(namespaces)

        paths.each do |raw_path|
          ["rails/generators", "generators"].each do |base|
            path = "#{base}/#{raw_path}_generator"

            begin
              require path
              return
            rescue LoadError => e
              raise unless e.message =~ /#{Regexp.escape(path)}$/
            rescue Exception => e
              warn "[WARNING] Could not load generator #{path.inspect}. Error: #{e.message}.\n#{e.backtrace.join("\n")}"
            end
          end
        end
      end

      # This will try to load any generator in the load path to show in help.
      def self.lookup! #:nodoc:
        $LOAD_PATH.each do |base|
          Dir[File.join(base, "{rails/generators,generators}", "**", "*_generator.rb")].each do |path|
            begin
              path = path.sub("#{base}/", "")
              require path
            rescue Exception
              # No problem
            end
          end
        end
      end

      # Convert namespaces to paths by replacing ":" for "/" and adding
      # an extra lookup. For example, "rails:model" should be searched
      # in both: "rails/model/model_generator" and "rails/model_generator".
      def self.namespaces_to_paths(namespaces) #:nodoc:
        paths = []
        namespaces.each do |namespace|
          pieces = namespace.split(":")
          paths << pieces.dup.push(pieces.last).join("/")
          paths << pieces.join("/")
        end
        paths.uniq!
        paths
      end
  end
end