vendor/rails/railties/doc/guides/html/2_2_release_notes.html

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 185                 </div>
 186
 187                 <h1 id="site_title"><span>Ruby on Rails</span></h1>
 188                 <h2 id="site_title_tagline">Sustainable productivity for web-application development</h2>
 189
 190                 <ul id="navMain">
 191                         <li class="first-child"><a href="http://www.rubyonrails.org/" title="Ruby on Rails" class="ruby_on_rails">Ruby on Rails</a></li>
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 193                 </ul>
 194         </div>
 195
 196         <div id="container">
 197
 198                 <div id="sidebar">
 199                         <h2>Chapters</h2>
 200                         <ol>
 201                                         <li>
 202                                         <a href="#_infrastructure">Infrastructure</a>
 203                                                 <ul>
 204
 205                                                         <li><a href="#_internationalization">Internationalization</a></li>
 206
 207                                                         <li><a href="#_compatibility_with_ruby_1_9_and_jruby">Compatibility with Ruby 1.9 and JRuby</a></li>
 208
 209                                                 </ul>
 210                                         </li>
 211                                         <li>
 212                                         <a href="#_documentation">Documentation</a>
 213                                         </li>
 214                                         <li>
 215                                         <a href="#_better_integration_with_http_out_of_the_box_etag_support">Better integration with HTTP : Out of the box ETag support</a>
 216                                         </li>
 217                                         <li>
 218                                         <a href="#_thread_safety">Thread Safety</a>
 219                                         </li>
 220                                         <li>
 221                                         <a href="#_active_record">Active Record</a>
 222                                                 <ul>
 223
 224                                                         <li><a href="#_transactional_migrations">Transactional Migrations</a></li>
 225
 226                                                         <li><a href="#_connection_pooling">Connection Pooling</a></li>
 227
 228                                                         <li><a href="#_hashes_for_join_table_conditions">Hashes for Join Table Conditions</a></li>
 229
 230                                                         <li><a href="#_new_dynamic_finders">New Dynamic Finders</a></li>
 231
 232                                                         <li><a href="#_associations_respect_private_protected_scope">Associations Respect Private/Protected Scope</a></li>
 233
 234                                                         <li><a href="#_other_activerecord_changes">Other ActiveRecord Changes</a></li>
 235
 236                                                 </ul>
 237                                         </li>
 238                                         <li>
 239                                         <a href="#_action_controller">Action Controller</a>
 240                                                 <ul>
 241
 242                                                         <li><a href="#_shallow_route_nesting">Shallow Route Nesting</a></li>
 243
 244                                                         <li><a href="#_method_arrays_for_member_or_collection_routes">Method Arrays for Member or Collection Routes</a></li>
 245
 246                                                         <li><a href="#_resources_with_specific_actions">Resources With Specific Actions</a></li>
 247
 248                                                         <li><a href="#_other_action_controller_changes">Other Action Controller Changes</a></li>
 249
 250                                                 </ul>
 251                                         </li>
 252                                         <li>
 253                                         <a href="#_action_view">Action View</a>
 254                                         </li>
 255                                         <li>
 256                                         <a href="#_action_mailer">Action Mailer</a>
 257                                         </li>
 258                                         <li>
 259                                         <a href="#_active_support">Active Support</a>
 260                                                 <ul>
 261
 262                                                         <li><a href="#_memoization">Memoization</a></li>
 263
 264                                                         <li><a href="#_tt_each_with_object_tt"><tt>each_with_object</tt></a></li>
 265
 266                                                         <li><a href="#_delegates_with_prefixes">Delegates With Prefixes</a></li>
 267
 268                                                         <li><a href="#_other_active_support_changes">Other Active Support Changes</a></li>
 269
 270                                                 </ul>
 271                                         </li>
 272                                         <li>
 273                                         <a href="#_railties">Railties</a>
 274                                                 <ul>
 275
 276                                                         <li><a href="#_tt_config_gems_tt"><tt>config.gems</tt></a></li>
 277
 278                                                         <li><a href="#_other_railties_changes">Other Railties Changes</a></li>
 279
 280                                                 </ul>
 281                                         </li>
 282                                         <li>
 283                                         <a href="#_deprecated">Deprecated</a>
 284                                         </li>
 285                                         <li>
 286                                         <a href="#_credits">Credits</a>
 287                                         </li>
 288                         </ol>
 289                 </div>
 290
 291                 <div id="content">
 292                                 <h1>Ruby on Rails 2.2 Release Notes</h1>
 293                         <div id="preamble">
 294 <div class="sectionbody">
 295 <div class="para"><p>Rails 2.2 delivers a number of new and improved features. This list covers the major upgrades, but doesn't include every little bug fix and change. If you want to see everything, check out the <a href="http://github.com/rails/rails/commits/master">list of commits</a> in the main Rails repository on GitHub.</p></div>
 296 <div class="para"><p>Along with Rails, 2.2 marks the launch of the <a href="http://guides.rubyonrails.org/">Ruby on Rails Guides</a>, the first results of the ongoing <a href="http://hackfest.rubyonrails.org/guide">Rails Guides hackfest</a>. This site will deliver high-quality documentation of the major features of Rails.</p></div>
 297 </div>
 298 </div>
 299 <h2 id="_infrastructure">1. Infrastructure</h2>
 300 <div class="sectionbody">
 301 <div class="para"><p>Rails 2.2 is a significant release for the infrastructure that keeps Rails humming along and connected to the rest of the world.</p></div>
 302 <h3 id="_internationalization">1.1. Internationalization</h3>
 303 <div class="para"><p>Rails 2.2 supplies an easy system for internationalization (or i18n, for those of you tired of typing).</p></div>
 304 <div class="ilist"><ul>
 305 <li>
 306 <p>
 307 Lead Contributors: Rails i18 Team
 308 </p>
 309 </li>
 310 <li>
 311 <p>
 312 More information :
 313 </p>
 314 <div class="ilist"><ul>
 315 <li>
 316 <p>
 317 <a href="http://rails-i18n.org">Official Rails i18 website</a>
 318 </p>
 319 </li>
 320 <li>
 321 <p>
 322 <a href="http://www.artweb-design.de/2008/7/18/finally-ruby-on-rails-gets-internationalized">Finally. Ruby on Rails gets internationalized</a>
 323 </p>
 324 </li>
 325 <li>
 326 <p>
 327 <a href="http://i18n-demo.phusion.nl">Localizing Rails : Demo application</a>
 328 </p>
 329 </li>
 330 </ul></div>
 331 </li>
 332 </ul></div>
 333 <h3 id="_compatibility_with_ruby_1_9_and_jruby">1.2. Compatibility with Ruby 1.9 and JRuby</h3>
 334 <div class="para"><p>Along with thread safety, a lot of work has been done to make Rails work well with JRuby and the upcoming Ruby 1.9. With Ruby 1.9 being a moving target, running edge Rails on edge Ruby is still a hit-or-miss proposition, but Rails is ready to make the transition to Ruby 1.9 when the latter is released.</p></div>
 335 </div>
 336 <h2 id="_documentation">2. Documentation</h2>
 337 <div class="sectionbody">
 338 <div class="para"><p>The internal documentation of Rails, in the form of code comments, has been improved in numerous places. In addition, the <a href="http://guides.rubyonrails.org/">Ruby on Rails Guides</a> project is the definitive source for information on major Rails components. In its first official release, the Guides page includes:</p></div>
 339 <div class="ilist"><ul>
 340 <li>
 341 <p>
 342 <a href="http://guides.rubyonrails.org/getting_started_with_rails.html">Getting Started with Rails</a>
 343 </p>
 344 </li>
 345 <li>
 346 <p>
 347 <a href="http://guides.rubyonrails.org/migrations.html">Rails Database Migrations</a>
 348 </p>
 349 </li>
 350 <li>
 351 <p>
 352 <a href="http://guides.rubyonrails.org/association_basics.html">Active Record Associations</a>
 353 </p>
 354 </li>
 355 <li>
 356 <p>
 357 <a href="http://guides.rubyonrails.org/finders.html">Active Record Finders</a>
 358 </p>
 359 </li>
 360 <li>
 361 <p>
 362 <a href="http://guides.rubyonrails.org/layouts_and_rendering.html">Layouts and Rendering in Rails</a>
 363 </p>
 364 </li>
 365 <li>
 366 <p>
 367 <a href="http://guides.rubyonrails.org/form_helpers.html">Action View Form Helpers</a>
 368 </p>
 369 </li>
 370 <li>
 371 <p>
 372 <a href="http://guides.rubyonrails.org/routing_outside_in.html">Rails Routing from the Outside In</a>
 373 </p>
 374 </li>
 375 <li>
 376 <p>
 377 <a href="http://guides.rubyonrails.org/actioncontroller_basics.html">Basics of Action Controller</a>
 378 </p>
 379 </li>
 380 <li>
 381 <p>
 382 <a href="http://guides.rubyonrails.org/caching_with_rails.html">Rails Caching</a>
 383 </p>
 384 </li>
 385 <li>
 386 <p>
 387 <a href="http://guides.rubyonrails.org/testing_rails_applications.html">Testing Rails Applications</a>
 388 </p>
 389 </li>
 390 <li>
 391 <p>
 392 <a href="http://guides.rubyonrails.org/security.html">Securing Rails Applications</a>
 393 </p>
 394 </li>
 395 <li>
 396 <p>
 397 <a href="http://guides.rubyonrails.org/debugging_rails_applications.html">Debugging Rails Applications</a>
 398 </p>
 399 </li>
 400 <li>
 401 <p>
 402 <a href="http://guides.rubyonrails.org/benchmarking_and_profiling.html">Benchmarking and Profiling Rails Applications</a>
 403 </p>
 404 </li>
 405 <li>
 406 <p>
 407 <a href="http://guides.rubyonrails.org/creating_plugins.html">The Basics of Creating Rails Plugins</a>
 408 </p>
 409 </li>
 410 </ul></div>
 411 <div class="para"><p>All told, the Guides provide tens of thousands of words of guidance for beginning and intermediate Rails developers.</p></div>
 412 <div class="para"><p>If you want to generate these guides locally, inside your application:</p></div>
 413 <div class="listingblock">
 414 <div class="content"><!-- Generator: GNU source-highlight 2.9
 415 by Lorenzo Bettini
 416 http://www.lorenzobettini.it
 417 http://www.gnu.org/software/src-highlite -->
 418 <pre><tt>rake doc<span style="color: #990000">:</span>guides
 419 </tt></pre></div></div>
 420 <div class="para"><p>This will put the guides inside <tt>RAILS_ROOT/doc/guides</tt> and you may start surfing straight away by opening <tt>RAILS_ROOT/doc/guides/index.html</tt> in your favourite browser.</p></div>
 421 <div class="ilist"><ul>
 422 <li>
 423 <p>
 424 Lead Contributors: <a href="http://guides.rails.info/authors.html">Rails Documentation Team</a>
 425 </p>
 426 </li>
 427 <li>
 428 <p>
 429 Major contributions from <a href="http://advogato.org/person/fxn/diary.html">Xavier Noria</a> and <a href="http://izumi.plan99.net/blog/">Hongli Lai</a>.
 430 </p>
 431 </li>
 432 <li>
 433 <p>
 434 More information:
 435 </p>
 436 <div class="ilist"><ul>
 437 <li>
 438 <p>
 439 <a href="http://hackfest.rubyonrails.org/guide">Rails Guides hackfest</a>
 440 </p>
 441 </li>
 442 <li>
 443 <p>
 444 <a href="http://weblog.rubyonrails.org/2008/5/2/help-improve-rails-documentation-on-git-branch">Help improve Rails documentation on Git branch</a>
 445 </p>
 446 </li>
 447 </ul></div>
 448 </li>
 449 </ul></div>
 450 </div>
 451 <h2 id="_better_integration_with_http_out_of_the_box_etag_support">3. Better integration with HTTP : Out of the box ETag support</h2>
 452 <div class="sectionbody">
 453 <div class="para"><p>Supporting the etag and last modified timestamp in HTTP headers means that Rails can now send back an empty response if it gets a request for a resource that hasn't been modified lately. This allows you to check whether a response needs to be sent at all.</p></div>
 454 <div class="listingblock">
 455 <div class="content"><!-- Generator: GNU source-highlight 2.9
 456 by Lorenzo Bettini
 457 http://www.lorenzobettini.it
 458 http://www.gnu.org/software/src-highlite -->
 459 <pre><tt><span style="font-weight: bold"><span style="color: #0000FF">class</span></span> ArticlesController <span style="color: #990000">&lt;</span> ApplicationController
 460   <span style="font-weight: bold"><span style="color: #0000FF">def</span></span> show_with_respond_to_block
 461     <span style="color: #009900">@article</span> <span style="color: #990000">=</span> Article<span style="color: #990000">.</span>find<span style="color: #990000">(</span>params<span style="color: #990000">[:</span>id<span style="color: #990000">])</span>
 462
 463     <span style="font-style: italic"><span style="color: #9A1900"># If the request sends headers that differs from the options provided to stale?, then</span></span>
 464     <span style="font-style: italic"><span style="color: #9A1900"># the request is indeed stale and the respond_to block is triggered (and the options</span></span>
 465     <span style="font-style: italic"><span style="color: #9A1900"># to the stale? call is set on the response).</span></span>
 466     <span style="font-style: italic"><span style="color: #9A1900">#</span></span>
 467     <span style="font-style: italic"><span style="color: #9A1900"># If the request headers match, then the request is fresh and the respond_to block is</span></span>
 468     <span style="font-style: italic"><span style="color: #9A1900"># not triggered. Instead the default render will occur, which will check the last-modified</span></span>
 469     <span style="font-style: italic"><span style="color: #9A1900"># and etag headers and conclude that it only needs to send a "304 Not Modified" instead</span></span>
 470     <span style="font-style: italic"><span style="color: #9A1900"># of rendering the template.</span></span>
 471     <span style="font-weight: bold"><span style="color: #0000FF">if</span></span> stale?<span style="color: #990000">(:</span>last_modified <span style="color: #990000">=&gt;</span> <span style="color: #009900">@article</span><span style="color: #990000">.</span>published_at<span style="color: #990000">.</span>utc<span style="color: #990000">,</span> <span style="color: #990000">:</span>etag <span style="color: #990000">=&gt;</span> <span style="color: #009900">@article</span><span style="color: #990000">)</span>
 472       respond_to <span style="font-weight: bold"><span style="color: #0000FF">do</span></span> <span style="color: #990000">|</span>wants<span style="color: #990000">|</span>
 473         <span style="font-style: italic"><span style="color: #9A1900"># normal response processing</span></span>
 474       <span style="font-weight: bold"><span style="color: #0000FF">end</span></span>
 475     <span style="font-weight: bold"><span style="color: #0000FF">end</span></span>
 476   <span style="font-weight: bold"><span style="color: #0000FF">end</span></span>
 477
 478   <span style="font-weight: bold"><span style="color: #0000FF">def</span></span> show_with_implied_render
 479     <span style="color: #009900">@article</span> <span style="color: #990000">=</span> Article<span style="color: #990000">.</span>find<span style="color: #990000">(</span>params<span style="color: #990000">[:</span>id<span style="color: #990000">])</span>
 480
 481     <span style="font-style: italic"><span style="color: #9A1900"># Sets the response headers and checks them against the request, if the request is stale</span></span>
 482     <span style="font-style: italic"><span style="color: #9A1900"># (i.e. no match of either etag or last-modified), then the default render of the template happens.</span></span>
 483     <span style="font-style: italic"><span style="color: #9A1900"># If the request is fresh, then the default render will return a "304 Not Modified"</span></span>
 484     <span style="font-style: italic"><span style="color: #9A1900"># instead of rendering the template.</span></span>
 485     fresh_when<span style="color: #990000">(:</span>last_modified <span style="color: #990000">=&gt;</span> <span style="color: #009900">@article</span><span style="color: #990000">.</span>published_at<span style="color: #990000">.</span>utc<span style="color: #990000">,</span> <span style="color: #990000">:</span>etag <span style="color: #990000">=&gt;</span> <span style="color: #009900">@article</span><span style="color: #990000">)</span>
 486   <span style="font-weight: bold"><span style="color: #0000FF">end</span></span>
 487 <span style="font-weight: bold"><span style="color: #0000FF">end</span></span>
 488 </tt></pre></div></div>
 489 </div>
 490 <h2 id="_thread_safety">4. Thread Safety</h2>
 491 <div class="sectionbody">
 492 <div class="para"><p>The work done to make Rails thread-safe is rolling out in Rails 2.2. Depending on your web server infrastructure, this means you can handle more requests with fewer copies of Rails in memory, leading to better server performance and higher utilization of multiple cores.</p></div>
 493 <div class="para"><p>To enable multithreaded dispatching in production mode of your application, add the following line in your <tt>config/environments/production.rb</tt>:</p></div>
 494 <div class="listingblock">
 495 <div class="content"><!-- Generator: GNU source-highlight 2.9
 496 by Lorenzo Bettini
 497 http://www.lorenzobettini.it
 498 http://www.gnu.org/software/src-highlite -->
 499 <pre><tt>config<span style="color: #990000">.</span>threadsafe!
 500 </tt></pre></div></div>
 501 <div class="ilist"><ul>
 502 <li>
 503 <p>
 504 More information :
 505 </p>
 506 <div class="ilist"><ul>
 507 <li>
 508 <p>
 509 <a href="http://m.onkey.org/2008/10/23/thread-safety-for-your-rails">Thread safety for your Rails</a>
 510 </p>
 511 </li>
 512 <li>
 513 <p>
 514 <a href="http://weblog.rubyonrails.org/2008/8/16/josh-peek-officially-joins-the-rails-core">Thread safety project announcement</a>
 515 </p>
 516 </li>
 517 <li>
 518 <p>
 519 <a href="http://blog.headius.com/2008/08/qa-what-thread-safe-rails-means.html">Q/A: What Thread-safe Rails Means</a>
 520 </p>
 521 </li>
 522 </ul></div>
 523 </li>
 524 </ul></div>
 525 </div>
 526 <h2 id="_active_record">5. Active Record</h2>
 527 <div class="sectionbody">
 528 <div class="para"><p>There are two big additions to talk about here: transactional migrations and pooled database transactions. There's also a new (and cleaner) syntax for join table conditions, as well as a number of smaller improvements.</p></div>
 529 <h3 id="_transactional_migrations">5.1. Transactional Migrations</h3>
 530 <div class="para"><p>Historically, multiple-step Rails migrations have been a source of trouble. If something went wrong during a migration, everything before the error changed the database and everything after the error wasn't applied. Also, the migration version was stored as having been executed, which means that it couldn't be simply rerun by <tt>rake db:migrate:redo</tt> after you fix the problem. Transactional migrations change this by wrapping migration steps in a DDL transaction, so that if any of them fail, the entire migration is undone. In Rails 2.2, transactional migrations are supported on PostgreSQL out of the box. The code is extensible to other database types in the future - and IBM has already extended it to support the DB2 adapter.</p></div>
 531 <div class="ilist"><ul>
 532 <li>
 533 <p>
 534 Lead Contributor: <a href="http://adam.blog.heroku.com/">Adam Wiggins</a>
 535 </p>
 536 </li>
 537 <li>
 538 <p>
 539 More information:
 540 </p>
 541 <div class="ilist"><ul>
 542 <li>
 543 <p>
 544 <a href="http://adam.blog.heroku.com/past/2008/9/3/ddl_transactions/">DDL Transactions</a>
 545 </p>
 546 </li>
 547 <li>
 548 <p>
 549 <a href="http://db2onrails.com/2008/11/08/a-major-milestone-for-db2-on-rails/">A major milestone for DB2 on Rails</a>
 550 </p>
 551 </li>
 552 </ul></div>
 553 </li>
 554 </ul></div>
 555 <h3 id="_connection_pooling">5.2. Connection Pooling</h3>
 556 <div class="para"><p>Connection pooling lets Rails distribute database requests across a pool of database connections that will grow to a maximum size (by default 5, but you can add a <tt>pool</tt> key to your <tt>database.yml</tt> to adjust this). This helps remove bottlenecks in applications that support many concurrent users. There's also a <tt>wait_timeout</tt> that defaults to 5 seconds before giving up. <tt>ActiveRecord::Base.connection_pool</tt> gives you direct access to the pool if you need it.</p></div>
 557 <div class="listingblock">
 558 <div class="content"><!-- Generator: GNU source-highlight 2.9
 559 by Lorenzo Bettini
 560 http://www.lorenzobettini.it
 561 http://www.gnu.org/software/src-highlite -->
 562 <pre><tt>development<span style="color: #990000">:</span>
 563   adapter<span style="color: #990000">:</span> mysql
 564   username<span style="color: #990000">:</span> root
 565   database<span style="color: #990000">:</span> sample_development
 566   pool<span style="color: #990000">:</span> <span style="color: #993399">10</span>
 567   wait_timeout<span style="color: #990000">:</span> <span style="color: #993399">10</span>
 568 </tt></pre></div></div>
 569 <div class="ilist"><ul>
 570 <li>
 571 <p>
 572 Lead Contributor: <a href="http://blog.nicksieger.com/">Nick Sieger</a>
 573 </p>
 574 </li>
 575 <li>
 576 <p>
 577 More information:
 578 </p>
 579 <div class="ilist"><ul>
 580 <li>
 581 <p>
 582 <a href="http://ryandaigle.com/articles/2008/9/7/what-s-new-in-edge-rails-connection-pools">What's New in Edge Rails: Connection Pools</a>
 583 </p>
 584 </li>
 585 </ul></div>
 586 </li>
 587 </ul></div>
 588 <h3 id="_hashes_for_join_table_conditions">5.3. Hashes for Join Table Conditions</h3>
 589 <div class="para"><p>You can now specify conditions on join tables using a hash. This is a big help if you need to query across complex joins.</p></div>
 590 <div class="listingblock">
 591 <div class="content"><!-- Generator: GNU source-highlight 2.9
 592 by Lorenzo Bettini
 593 http://www.lorenzobettini.it
 594 http://www.gnu.org/software/src-highlite -->
 595 <pre><tt><span style="font-weight: bold"><span style="color: #0000FF">class</span></span> Photo <span style="color: #990000">&lt;</span> ActiveRecord<span style="color: #990000">::</span>Base
 596   belongs_to <span style="color: #990000">:</span>product
 597 <span style="font-weight: bold"><span style="color: #0000FF">end</span></span>
 598
 599 <span style="font-weight: bold"><span style="color: #0000FF">class</span></span> Product <span style="color: #990000">&lt;</span> ActiveRecord<span style="color: #990000">::</span>Base
 600   has_many <span style="color: #990000">:</span>photos
 601 <span style="font-weight: bold"><span style="color: #0000FF">end</span></span>
 602
 603 <span style="font-style: italic"><span style="color: #9A1900"># Get all products with copyright-free photos:</span></span>
 604 Product<span style="color: #990000">.</span>all<span style="color: #990000">(:</span>joins <span style="color: #990000">=&gt;</span> <span style="color: #990000">:</span>photos<span style="color: #990000">,</span> <span style="color: #990000">:</span>conditions <span style="color: #990000">=&gt;</span> <span style="color: #FF0000">{</span> <span style="color: #990000">:</span>photos <span style="color: #990000">=&gt;</span> <span style="color: #FF0000">{</span> <span style="color: #990000">:</span>copyright <span style="color: #990000">=&gt;</span> <span style="font-weight: bold"><span style="color: #0000FF">false</span></span> <span style="color: #FF0000">}}</span><span style="color: #990000">)</span>
 605 </tt></pre></div></div>
 606 <div class="ilist"><ul>
 607 <li>
 608 <p>
 609 More information:
 610 </p>
 611 <div class="ilist"><ul>
 612 <li>
 613 <p>
 614 <a href="http://ryandaigle.com/articles/2008/7/7/what-s-new-in-edge-rails-easy-join-table-conditions">What's New in Edge Rails: Easy Join Table Conditions</a>
 615 </p>
 616 </li>
 617 </ul></div>
 618 </li>
 619 </ul></div>
 620 <h3 id="_new_dynamic_finders">5.4. New Dynamic Finders</h3>
 621 <div class="para"><p>Two new sets of methods have been added to Active Record's dynamic finders family.</p></div>
 622 <h4 id="_tt_find_last_by_lt_attribute_gt_tt">5.4.1. <tt>find_last_by_&lt;attribute&gt;</tt></h4>
 623 <div class="para"><p>The <tt>find_last_by_&lt;attribute&gt;</tt> method is equivalent to <tt>Model.last(:conditions &#8658; {:attribute &#8658; value})</tt></p></div>
 624 <div class="listingblock">
 625 <div class="content"><!-- Generator: GNU source-highlight 2.9
 626 by Lorenzo Bettini
 627 http://www.lorenzobettini.it
 628 http://www.gnu.org/software/src-highlite -->
 629 <pre><tt><span style="font-style: italic"><span style="color: #9A1900"># Get the last user who signed up from London</span></span>
 630 User<span style="color: #990000">.</span>find_last_by_city<span style="color: #990000">(</span><span style="color: #FF0000">'London'</span><span style="color: #990000">)</span>
 631 </tt></pre></div></div>
 632 <div class="ilist"><ul>
 633 <li>
 634 <p>
 635 Lead Contributor: <a href="http://www.workingwithrails.com/person/9147-emilio-tagua">Emilio Tagua</a>
 636 </p>
 637 </li>
 638 </ul></div>
 639 <h4 id="_tt_find_by_lt_attribute_gt_tt">5.4.2. <tt>find_by_&lt;attribute&gt;!</tt></h4>
 640 <div class="para"><p>The new bang! version of <tt>find_by_&lt;attribute&gt;!</tt> is equivalent to <tt>Model.first(:conditions &#8658; {:attribute &#8658; value}) || raise ActiveRecord::RecordNotFound</tt> Instead of returning <tt>nil</tt> if it can't find a matching record, this method will raise an exception if it cannot find a match.</p></div>
 641 <div class="listingblock">
 642 <div class="content"><!-- Generator: GNU source-highlight 2.9
 643 by Lorenzo Bettini
 644 http://www.lorenzobettini.it
 645 http://www.gnu.org/software/src-highlite -->
 646 <pre><tt><span style="font-style: italic"><span style="color: #9A1900"># Raise ActiveRecord::RecordNotFound exception if 'Moby' hasn't signed up yet!</span></span>
 647 User<span style="color: #990000">.</span>find_by_name!<span style="color: #990000">(</span><span style="color: #FF0000">'Moby'</span><span style="color: #990000">)</span>
 648 </tt></pre></div></div>
 649 <div class="ilist"><ul>
 650 <li>
 651 <p>
 652 Lead Contributor: <a href="http://blog.hasmanythrough.com">Josh Susser</a>
 653 </p>
 654 </li>
 655 </ul></div>
 656 <h3 id="_associations_respect_private_protected_scope">5.5. Associations Respect Private/Protected Scope</h3>
 657 <div class="para"><p>Active Record association proxies now respect the scope of methods on the proxied object. Previously (given User has_one :account) <tt>@user.account.private_method</tt> would call the private method on the associated Account object. That fails in Rails 2.2; if you need this functionality, you should use <tt>@user.account.send(:private_method)</tt> (or make the method public instead of private or protected). Please note that if you're overriding <tt>method_missing</tt>, you should also override <tt>respond_to</tt> to match the behavior in order for associations to function normally.</p></div>
 658 <div class="ilist"><ul>
 659 <li>
 660 <p>
 661 Lead Contributor: Adam Milligan
 662 </p>
 663 </li>
 664 <li>
 665 <p>
 666 More information:
 667 </p>
 668 <div class="ilist"><ul>
 669 <li>
 670 <p>
 671 <a href="http://afreshcup.com/2008/10/24/rails-22-change-private-methods-on-association-proxies-are-private/">Rails 2.2 Change: Private Methods on Association Proxies are Private</a>
 672 </p>
 673 </li>
 674 </ul></div>
 675 </li>
 676 </ul></div>
 677 <h3 id="_other_activerecord_changes">5.6. Other ActiveRecord Changes</h3>
 678 <div class="ilist"><ul>
 679 <li>
 680 <p>
 681 <tt>rake db:migrate:redo</tt> now accepts an optional VERSION to target that specific migration to redo
 682 </p>
 683 </li>
 684 <li>
 685 <p>
 686 Set <tt>config.active_record.timestamped_migrations = false</tt> to have migrations with numeric prefix instead of UTC timestamp.
 687 </p>
 688 </li>
 689 <li>
 690 <p>
 691 Counter cache columns (for associations declared with <tt>:counter_cache &#8658; true</tt>) do not need to be initialized to zero any longer.
 692 </p>
 693 </li>
 694 <li>
 695 <p>
 696 <tt>ActiveRecord::Base.human_name</tt> for an internationalization-aware humane translation of model names
 697 </p>
 698 </li>
 699 </ul></div>
 700 </div>
 701 <h2 id="_action_controller">6. Action Controller</h2>
 702 <div class="sectionbody">
 703 <div class="para"><p>On the controller side, there are several changes that will help tidy up your routes. There are also some internal changes in the routing engine to lower memory usage on complex applications.</p></div>
 704 <h3 id="_shallow_route_nesting">6.1. Shallow Route Nesting</h3>
 705 <div class="para"><p>Shallow route nesting provides a solution to the well-known difficulty of using deeply-nested resources. With shallow nesting, you need only supply enough information to uniquely identify the resource that you want to work with.</p></div>
 706 <div class="listingblock">
 707 <div class="content"><!-- Generator: GNU source-highlight 2.9
 708 by Lorenzo Bettini
 709 http://www.lorenzobettini.it
 710 http://www.gnu.org/software/src-highlite -->
 711 <pre><tt>map<span style="color: #990000">.</span>resources <span style="color: #990000">:</span>publishers<span style="color: #990000">,</span> <span style="color: #990000">:</span>shallow <span style="color: #990000">=&gt;</span> <span style="font-weight: bold"><span style="color: #0000FF">true</span></span> <span style="font-weight: bold"><span style="color: #0000FF">do</span></span> <span style="color: #990000">|</span>publisher<span style="color: #990000">|</span>
 712   publisher<span style="color: #990000">.</span>resources <span style="color: #990000">:</span>magazines <span style="font-weight: bold"><span style="color: #0000FF">do</span></span> <span style="color: #990000">|</span>magazine<span style="color: #990000">|</span>
 713     magazine<span style="color: #990000">.</span>resources <span style="color: #990000">:</span>photos
 714   <span style="font-weight: bold"><span style="color: #0000FF">end</span></span>
 715 <span style="font-weight: bold"><span style="color: #0000FF">end</span></span>
 716 </tt></pre></div></div>
 717 <div class="para"><p>This will enable recognition of (among others) these routes:</p></div>
 718 <div class="listingblock">
 719 <div class="content">
 720 <pre><tt>/publishers/1           ==&gt; publisher_path(1)
 721 /publishers/1/magazines ==&gt; publisher_magazines_path(1)
 722 /magazines/2            ==&gt; magazine_path(2)
 723 /magazines/2/photos     ==&gt; magazines_photos_path(2)
 724 /photos/3               ==&gt; photo_path(3)</tt></pre>
 725 </div></div>
 726 <div class="ilist"><ul>
 727 <li>
 728 <p>
 729 Lead Contributor: <a href="http://www.unwwwired.net/">S. Brent Faulkner</a>
 730 </p>
 731 </li>
 732 <li>
 733 <p>
 734 More information:
 735 </p>
 736 <div class="ilist"><ul>
 737 <li>
 738 <p>
 739 <a href="http://guides.rails.info/routing/routing_outside_in.html#_nested_resources">Rails Routing from the Outside In</a>
 740 </p>
 741 </li>
 742 <li>
 743 <p>
 744 <a href="http://ryandaigle.com/articles/2008/9/7/what-s-new-in-edge-rails-shallow-routes">What's New in Edge Rails: Shallow Routes</a>
 745 </p>
 746 </li>
 747 </ul></div>
 748 </li>
 749 </ul></div>
 750 <h3 id="_method_arrays_for_member_or_collection_routes">6.2. Method Arrays for Member or Collection Routes</h3>
 751 <div class="para"><p>You can now supply an array of methods for new member or collection routes. This removes the annoyance of having to define a route as accepting any verb as soon as you need it to handle more than one. With Rails 2.2, this is a legitimate route declaration:</p></div>
 752 <div class="listingblock">
 753 <div class="content"><!-- Generator: GNU source-highlight 2.9
 754 by Lorenzo Bettini
 755 http://www.lorenzobettini.it
 756 http://www.gnu.org/software/src-highlite -->
 757 <pre><tt>map<span style="color: #990000">.</span>resources <span style="color: #990000">:</span>photos<span style="color: #990000">,</span> <span style="color: #990000">:</span>collection <span style="color: #990000">=&gt;</span> <span style="color: #FF0000">{</span> <span style="color: #990000">:</span>search <span style="color: #990000">=&gt;</span> <span style="color: #990000">[:</span>get<span style="color: #990000">,</span> <span style="color: #990000">:</span>post<span style="color: #990000">]</span> <span style="color: #FF0000">}</span>
 758 </tt></pre></div></div>
 759 <div class="ilist"><ul>
 760 <li>
 761 <p>
 762 Lead Contributor: <a href="http://brennandunn.com/">Brennan Dunn</a>
 763 </p>
 764 </li>
 765 </ul></div>
 766 <h3 id="_resources_with_specific_actions">6.3. Resources With Specific Actions</h3>
 767 <div class="para"><p>By default, when you use <tt>map.resources</tt> to create a route, Rails generates routes for seven default actions (index, show, create, new, edit, update, and destroy). But each of these routes takes up memory in your application, and causes Rails to generate additional routing logic. Now you can use the <tt>:only</tt> and <tt>:except</tt> options to fine-tune the routes that Rails will generate for resources. You can supply a single action, an array of actions, or the special <tt>:all</tt> or <tt>:none</tt> options. These options are inherited by nested resources.</p></div>
 768 <div class="listingblock">
 769 <div class="content"><!-- Generator: GNU source-highlight 2.9
 770 by Lorenzo Bettini
 771 http://www.lorenzobettini.it
 772 http://www.gnu.org/software/src-highlite -->
 773 <pre><tt>map<span style="color: #990000">.</span>resources <span style="color: #990000">:</span>photos<span style="color: #990000">,</span> <span style="color: #990000">:</span>only <span style="color: #990000">=&gt;</span> <span style="color: #990000">[:</span>index<span style="color: #990000">,</span> <span style="color: #990000">:</span>show<span style="color: #990000">]</span>
 774 map<span style="color: #990000">.</span>resources <span style="color: #990000">:</span>products<span style="color: #990000">,</span> <span style="color: #990000">:</span>except <span style="color: #990000">=&gt;</span> <span style="color: #990000">:</span>destroy
 775 </tt></pre></div></div>
 776 <div class="ilist"><ul>
 777 <li>
 778 <p>
 779 Lead Contributor: <a href="http://experthuman.com/">Tom Stuart</a>
 780 </p>
 781 </li>
 782 </ul></div>
 783 <h3 id="_other_action_controller_changes">6.4. Other Action Controller Changes</h3>
 784 <div class="ilist"><ul>
 785 <li>
 786 <p>
 787 You can now easily <a href="http://m.onkey.org/2008/7/20/rescue-from-dispatching">show a custom error page</a> for exceptions raised while routing a request.
 788 </p>
 789 </li>
 790 <li>
 791 <p>
 792 The HTTP Accept header is disabled by default now. You should prefer the use of formatted URLs (such as <tt>/customers/1.xml</tt>) to indicate the format that you want. If you need the Accept headers, you can turn them back on with <tt>config.action_controller.user_accept_header = true</tt>.
 793 </p>
 794 </li>
 795 <li>
 796 <p>
 797 Benchmarking numbers are now reported in milliseconds rather than tiny fractions of seconds
 798 </p>
 799 </li>
 800 <li>
 801 <p>
 802 Rails now supports HTTP-only cookies (and uses them for sessions), which help mitigate some cross-site scripting risks in newer browsers.
 803 </p>
 804 </li>
 805 <li>
 806 <p>
 807 <tt>redirect_to</tt> now fully supports URI schemes (so, for example, you can redirect to a svn+ssh: URI).
 808 </p>
 809 </li>
 810 <li>
 811 <p>
 812 <tt>render</tt> now supports a <tt>:js</tt> option to render plain vanilla javascript with the right mime type.
 813 </p>
 814 </li>
 815 <li>
 816 <p>
 817 Request forgery protection has been tightened up to apply to HTML-formatted content requests only.
 818 </p>
 819 </li>
 820 <li>
 821 <p>
 822 Polymorphic URLs behave more sensibly if a passed parameter is nil. For example, calling <tt>polymorphic_path([@project, @date, @area])</tt> with a nil date will give you <tt>project_area_path</tt>.
 823 </p>
 824 </li>
 825 </ul></div>
 826 </div>
 827 <h2 id="_action_view">7. Action View</h2>
 828 <div class="sectionbody">
 829 <div class="ilist"><ul>
 830 <li>
 831 <p>
 832 <tt>javascript_include_tag</tt> and <tt>stylesheet_link_tag</tt> support a new <tt>:recursive</tt> option to be used along with <tt>:all</tt>, so that you can load an entire tree of files with a single line of code.
 833 </p>
 834 </li>
 835 <li>
 836 <p>
 837 The included Prototype javascript library has been upgraded to version 1.6.0.3.
 838 </p>
 839 </li>
 840 <li>
 841 <p>
 842 <tt>RJS#page.reload</tt> to reload the browser's current location via javascript
 843 </p>
 844 </li>
 845 <li>
 846 <p>
 847 The <tt>atom_feed</tt> helper now takes an <tt>:instruct</tt> option to let you insert XML processing instructions.
 848 </p>
 849 </li>
 850 </ul></div>
 851 </div>
 852 <h2 id="_action_mailer">8. Action Mailer</h2>
 853 <div class="sectionbody">
 854 <div class="para"><p>Action Mailer now supports mailer layouts. You can make your HTML emails as pretty as your in-browser views by supplying an appropriately-named layout - for example, the <tt>CustomerMailer</tt> class expects to use <tt>layouts/customer_mailer.html.erb</tt>.</p></div>
 855 <div class="ilist"><ul>
 856 <li>
 857 <p>
 858 More information:
 859 </p>
 860 <div class="ilist"><ul>
 861 <li>
 862 <p>
 863 <a href="http://ryandaigle.com/articles/2008/9/7/what-s-new-in-edge-rails-mailer-layouts">What's New in Edge Rails: Mailer Layouts</a>
 864 </p>
 865 </li>
 866 </ul></div>
 867 </li>
 868 </ul></div>
 869 <div class="para"><p>Action Mailer now offers built-in support for GMail's SMTP servers, by turning on STARTTLS automatically. This requires Ruby 1.8.7 to be installed.</p></div>
 870 </div>
 871 <h2 id="_active_support">9. Active Support</h2>
 872 <div class="sectionbody">
 873 <div class="para"><p>Active Support now offers built-in memoization for Rails applications, the <tt>each_with_object</tt> method, prefix support on delegates, and various other new utility methods.</p></div>
 874 <h3 id="_memoization">9.1. Memoization</h3>
 875 <div class="para"><p>Memoization is a pattern of initializing a method once and then stashing its value away for repeat use. You've probably used this pattern in your own applications:</p></div>
 876 <div class="listingblock">
 877 <div class="content"><!-- Generator: GNU source-highlight 2.9
 878 by Lorenzo Bettini
 879 http://www.lorenzobettini.it
 880 http://www.gnu.org/software/src-highlite -->
 881 <pre><tt><span style="font-weight: bold"><span style="color: #0000FF">def</span></span> full_name
 882   <span style="color: #009900">@full_name</span> <span style="color: #990000">||=</span> <span style="color: #FF0000">"#{first_name} #{last_name}"</span>
 883 <span style="font-weight: bold"><span style="color: #0000FF">end</span></span>
 884 </tt></pre></div></div>
 885 <div class="para"><p>Memoization lets you handle this task in a declarative fashion:</p></div>
 886 <div class="listingblock">
 887 <div class="content"><!-- Generator: GNU source-highlight 2.9
 888 by Lorenzo Bettini
 889 http://www.lorenzobettini.it
 890 http://www.gnu.org/software/src-highlite -->
 891 <pre><tt>extend ActiveSupport<span style="color: #990000">::</span>Memoizable
 892
 893 <span style="font-weight: bold"><span style="color: #0000FF">def</span></span> full_name
 894   <span style="color: #FF0000">"#{first_name} #{last_name}"</span>
 895 <span style="font-weight: bold"><span style="color: #0000FF">end</span></span>
 896 memoize <span style="color: #990000">:</span>full_name
 897 </tt></pre></div></div>
 898 <div class="para"><p>Other features of memoization include <tt>unmemoize</tt>, <tt>unmemoize_all</tt>, and <tt>memoize_all</tt> to turn memoization on or off.</p></div>
 899 <div class="ilist"><ul>
 900 <li>
 901 <p>
 902 Lead Contributor: <a href="http://joshpeek.com/">Josh Peek</a>
 903 </p>
 904 </li>
 905 <li>
 906 <p>
 907 More information:
 908 </p>
 909 <div class="ilist"><ul>
 910 <li>
 911 <p>
 912 <a href="http://ryandaigle.com/articles/2008/7/16/what-s-new-in-edge-rails-memoization">What's New in Edge Rails: Easy Memoization</a>
 913 </p>
 914 </li>
 915 <li>
 916 <p>
 917 <a href="http://www.railway.at/articles/2008/09/20/a-guide-to-memoization">Memo-what? A Guide to Memoization</a>
 918 </p>
 919 </li>
 920 </ul></div>
 921 </li>
 922 </ul></div>
 923 <h3 id="_tt_each_with_object_tt">9.2. <tt>each_with_object</tt></h3>
 924 <div class="para"><p>The <tt>each_with_object</tt> method provides an alternative to <tt>inject</tt>, using a method backported from Ruby 1.9. It iterates over a collection, passing the current element and the memo into the block.</p></div>
 925 <div class="listingblock">
 926 <div class="content"><!-- Generator: GNU source-highlight 2.9
 927 by Lorenzo Bettini
 928 http://www.lorenzobettini.it
 929 http://www.gnu.org/software/src-highlite -->
 930 <pre><tt><span style="color: #990000">%</span>w<span style="color: #990000">(</span>foo bar<span style="color: #990000">).</span>each_with_object<span style="color: #990000">(</span><span style="color: #FF0000">{}</span><span style="color: #990000">)</span> <span style="color: #FF0000">{</span> <span style="color: #990000">|</span>str<span style="color: #990000">,</span> hsh<span style="color: #990000">|</span> hsh<span style="color: #990000">[</span>str<span style="color: #990000">]</span> <span style="color: #990000">=</span> str<span style="color: #990000">.</span>upcase <span style="color: #FF0000">}</span> <span style="font-style: italic"><span style="color: #9A1900">#=&gt; {'foo' =&gt; 'FOO', 'bar' =&gt; 'BAR'}</span></span>
 931 </tt></pre></div></div>
 932 <div class="para"><p>Lead Contributor: <a href="http://therealadam.com/">Adam Keys</a></p></div>
 933 <h3 id="_delegates_with_prefixes">9.3. Delegates With Prefixes</h3>
 934 <div class="para"><p>If you delegate behavior from one class to another, you can now specify a prefix that will be used to identify the delegated methods. For example:</p></div>
 935 <div class="listingblock">
 936 <div class="content"><!-- Generator: GNU source-highlight 2.9
 937 by Lorenzo Bettini
 938 http://www.lorenzobettini.it
 939 http://www.gnu.org/software/src-highlite -->
 940 <pre><tt><span style="font-weight: bold"><span style="color: #0000FF">class</span></span> Vendor <span style="color: #990000">&lt;</span> ActiveRecord<span style="color: #990000">::</span>Base
 941   has_one <span style="color: #990000">:</span>account
 942   delegate <span style="color: #990000">:</span>email<span style="color: #990000">,</span> <span style="color: #990000">:</span>password<span style="color: #990000">,</span> <span style="color: #990000">:</span>to <span style="color: #990000">=&gt;</span> <span style="color: #990000">:</span>account<span style="color: #990000">,</span> <span style="color: #990000">:</span>prefix <span style="color: #990000">=&gt;</span> <span style="font-weight: bold"><span style="color: #0000FF">true</span></span>
 943 <span style="font-weight: bold"><span style="color: #0000FF">end</span></span>
 944 </tt></pre></div></div>
 945 <div class="para"><p>This will produce delegated methods <tt>vendor#account_email</tt> and <tt>vendor#account_password</tt>. You can also specify a custom prefix:</p></div>
 946 <div class="listingblock">
 947 <div class="content"><!-- Generator: GNU source-highlight 2.9
 948 by Lorenzo Bettini
 949 http://www.lorenzobettini.it
 950 http://www.gnu.org/software/src-highlite -->
 951 <pre><tt><span style="font-weight: bold"><span style="color: #0000FF">class</span></span> Vendor <span style="color: #990000">&lt;</span> ActiveRecord<span style="color: #990000">::</span>Base
 952   has_one <span style="color: #990000">:</span>account
 953   delegate <span style="color: #990000">:</span>email<span style="color: #990000">,</span> <span style="color: #990000">:</span>password<span style="color: #990000">,</span> <span style="color: #990000">:</span>to <span style="color: #990000">=&gt;</span> <span style="color: #990000">:</span>account<span style="color: #990000">,</span> <span style="color: #990000">:</span>prefix <span style="color: #990000">=&gt;</span> <span style="color: #990000">:</span>owner
 954 <span style="font-weight: bold"><span style="color: #0000FF">end</span></span>
 955 </tt></pre></div></div>
 956 <div class="para"><p>This will produce delegated methods <tt>vendor#owner_email</tt> and <tt>vendor#owner_password</tt>.</p></div>
 957 <div class="para"><p>Lead Contributor: <a href="http://workingwithrails.com/person/5830-daniel-schierbeck">Daniel Schierbeck</a></p></div>
 958 <h3 id="_other_active_support_changes">9.4. Other Active Support Changes</h3>
 959 <div class="ilist"><ul>
 960 <li>
 961 <p>
 962 Extensive updates to <tt>ActiveSupport::Multibyte</tt>, including Ruby 1.9 compatibility fixes.
 963 </p>
 964 </li>
 965 <li>
 966 <p>
 967 The addition of <tt>ActiveSupport::Rescuable</tt> allows any class to mix in the <tt>rescue_from</tt> syntax.
 968 </p>
 969 </li>
 970 <li>
 971 <p>
 972 <tt>past?</tt>, <tt>today?</tt> and <tt>future?</tt> for <tt>Date</tt> and <tt>Time</tt> classes to facilitate date/time comparisons.
 973 </p>
 974 </li>
 975 <li>
 976 <p>
 977 <tt>Array#second</tt> through <tt>Array#fifth</tt> as aliases for <tt>Array#[1]</tt> through <tt>Array#[4]</tt>
 978 </p>
 979 </li>
 980 <li>
 981 <p>
 982 <tt>Enumerable#many?</tt> to encapsulate <tt>collection.size &gt; 1</tt>
 983 </p>
 984 </li>
 985 <li>
 986 <p>
 987 <tt>Inflector#parameterize</tt> produces a URL-ready version of its input, for use in <tt>to_param</tt>.
 988 </p>
 989 </li>
 990 <li>
 991 <p>
 992 <tt>Time#advance</tt> recognizes fractional days and weeks, so you can do <tt>1.7.weeks.ago</tt>, <tt>1.5.hours.since</tt>, and so on.
 993 </p>
 994 </li>
 995 <li>
 996 <p>
 997 The included TzInfo library has been upgraded to version 0.3.12.
 998 </p>
 999 </li>
1000 <li>
1001 <p>
1002 <tt>ActiveSuport::StringInquirer</tt> gives you a pretty way to test for equality in strings: <tt>ActiveSupport::StringInquirer.new("abc").abc? &#8658; true</tt>
1003 </p>
1004 </li>
1005 </ul></div>
1006 </div>
1007 <h2 id="_railties">10. Railties</h2>
1008 <div class="sectionbody">
1009 <div class="para"><p>In Railties (the core code of Rails itself) the biggest changes are in the <tt>config.gems</tt> mechanism.</p></div>
1010 <h3 id="_tt_config_gems_tt">10.1. <tt>config.gems</tt></h3>
1011 <div class="para"><p>To avoid deployment issues and make Rails applications more self-contained, it's possible to place copies of all of the gems that your Rails application requires in <tt>/vendor/gems</tt>. This capability first appeared in Rails 2.1, but it's much more flexible and robust in Rails 2.2, handling complicated dependencies between gems. Gem management in Rails includes these commands:</p></div>
1012 <div class="ilist"><ul>
1013 <li>
1014 <p>
1015 <tt>config.gem <em>gem_name</em></tt> in your <tt>config/environment.rb</tt> file
1016 </p>
1017 </li>
1018 <li>
1019 <p>
1020 <tt>rake gems</tt> to list all configured gems, as well as whether they (and their dependencies) are installed or frozen
1021 </p>
1022 </li>
1023 <li>
1024 <p>
1025 <tt>rake gems:install</tt> to install missing gems to the computer
1026 </p>
1027 </li>
1028 <li>
1029 <p>
1030 <tt>rake gems:unpack</tt> to place a copy of the required gems into <tt>/vendor/gems</tt>
1031 </p>
1032 </li>
1033 <li>
1034 <p>
1035 <tt>rake gems:unpack:dependencies</tt> to get copies of the required gems and their dependencies into <tt>/vendor/gems</tt>
1036 </p>
1037 </li>
1038 <li>
1039 <p>
1040 <tt>rake gems:build</tt> to build any missing native extensions
1041 </p>
1042 </li>
1043 <li>
1044 <p>
1045 <tt>rake gems:refresh_specs</tt> to bring vendored gems created with Rails 2.1 into alignment with the Rails 2.2 way of storing them
1046 </p>
1047 </li>
1048 </ul></div>
1049 <div class="para"><p>You can unpack or install a single gem by specifying <tt>GEM=<em>gem_name</em></tt> on the command line.</p></div>
1050 <div class="ilist"><ul>
1051 <li>
1052 <p>
1053 Lead Contributor: <a href="http://github.com/al2o3cr">Matt Jones</a>
1054 </p>
1055 </li>
1056 <li>
1057 <p>
1058 More information:
1059 </p>
1060 <div class="ilist"><ul>
1061 <li>
1062 <p>
1063 <a href="http://ryandaigle.com/articles/2008/4/1/what-s-new-in-edge-rails-gem-dependencies">What's New in Edge Rails: Gem Dependencies</a>
1064 </p>
1065 </li>
1066 <li>
1067 <p>
1068 <a href="http://afreshcup.com/2008/10/25/rails-212-and-22rc1-update-your-rubygems/">Rails 2.1.2 and 2.2RC1: Update Your RubyGems</a>
1069 </p>
1070 </li>
1071 </ul></div>
1072 </li>
1073 </ul></div>
1074 <h3 id="_other_railties_changes">10.2. Other Railties Changes</h3>
1075 <div class="ilist"><ul>
1076 <li>
1077 <p>
1078 If you're a fan of the <a href="http://code.macournoyer.com/thin/">Thin</a> web server, you'll be happy to know that <tt>script/server</tt> now supports Thin directly.
1079 </p>
1080 </li>
1081 <li>
1082 <p>
1083 <tt>script/plugin install &lt;plugin&gt; -r &lt;revision&gt;</tt> now works with git-based as well as svn-based plugins.
1084 </p>
1085 </li>
1086 <li>
1087 <p>
1088 <tt>script/console</tt> now supports a <tt>&#8212;debugger</tt> option
1089 </p>
1090 </li>
1091 <li>
1092 <p>
1093 Instructions for setting up a continuous integration server to build Rails itself are included in the Rails source
1094 </p>
1095 </li>
1096 <li>
1097 <p>
1098 <tt>rake notes:custom ANNOTATION=MYFLAG</tt> lets you list out custom annotations.
1099 </p>
1100 </li>
1101 <li>
1102 <p>
1103 Wrapped <tt>Rails.env</tt> in <tt>StringInquirer</tt> so you can do <tt>Rails.env.development?</tt>
1104 </p>
1105 </li>
1106 <li>
1107 <p>
1108 To eliminate deprecation warnings and properly handle gem dependencies, Rails now requires rubygems 1.3.1 or higher.
1109 </p>
1110 </li>
1111 </ul></div>
1112 </div>
1113 <h2 id="_deprecated">11. Deprecated</h2>
1114 <div class="sectionbody">
1115 <div class="para"><p>A few pieces of older code are deprecated in this release:</p></div>
1116 <div class="ilist"><ul>
1117 <li>
1118 <p>
1119 <tt>Rails::SecretKeyGenerator</tt> has been replaced by <tt>ActiveSupport::SecureRandom</tt>
1120 </p>
1121 </li>
1122 <li>
1123 <p>
1124 <tt>render_component</tt> is deprecated. There's a <a href="http://github.com/rails/render_component/tree/master">render_components plugin</a> available if you need this functionality.
1125 </p>
1126 </li>
1127 <li>
1128 <p>
1129 Implicit local assignments when rendering partials has been deprecated.
1130 </p>
1131 </li>
1132 </ul></div>
1133 <div class="listingblock">
1134 <div class="content"><!-- Generator: GNU source-highlight 2.9
1135 by Lorenzo Bettini
1136 http://www.lorenzobettini.it
1137 http://www.gnu.org/software/src-highlite -->
1138 <pre><tt><span style="font-weight: bold"><span style="color: #0000FF">def</span></span> partial_with_implicit_local_assignment
1139   <span style="color: #009900">@customer</span> <span style="color: #990000">=</span> Customer<span style="color: #990000">.</span>new<span style="color: #990000">(</span><span style="color: #FF0000">"Marcel"</span><span style="color: #990000">)</span>
1140   render <span style="color: #990000">:</span>partial <span style="color: #990000">=&gt;</span> <span style="color: #FF0000">"customer"</span>
1141 <span style="font-weight: bold"><span style="color: #0000FF">end</span></span>
1142 </tt></pre></div></div>
1143 <div class="para"><p>Previously the above code made available a local variable called <tt>customer</tt> inside the partial <em>customer</em>. You should explicitly pass all the variables via :locals hash now.</p></div>
1144 <div class="ilist"><ul>
1145 <li>
1146 <p>
1147 <tt>country_select</tt> has been removed. See the <a href="http://www.rubyonrails.org/deprecation/list-of-countries">deprecation page</a> for more information and a plugin replacement.
1148 </p>
1149 </li>
1150 <li>
1151 <p>
1152 <tt>ActiveRecord::Base.allow_concurrency</tt> no longer has any effect.
1153 </p>
1154 </li>
1155 <li>
1156 <p>
1157 <tt>ActiveRecord::Errors.default_error_messages</tt> has been deprecated in favor of <tt>I18n.translate(<em>activerecord.errors.messages</em>)</tt>
1158 </p>
1159 </li>
1160 <li>
1161 <p>
1162 The <tt>%s</tt> and <tt>%d</tt> interpolation syntax for internationalization is deprecated.
1163 </p>
1164 </li>
1165 <li>
1166 <p>
1167 <tt>String#chars</tt> has been deprecated in favor of <tt>String#mb_chars</tt>.
1168 </p>
1169 </li>
1170 <li>
1171 <p>
1172 Durations of fractional months or fractional years are deprecated. Use Ruby's core <tt>Date</tt> and <tt>Time</tt> class arithmetic instead.
1173 </p>
1174 </li>
1175 </ul></div>
1176 </div>
1177 <h2 id="_credits">12. Credits</h2>
1178 <div class="sectionbody">
1179 <div class="para"><p>Release notes compiled by <a href="http://afreshcup.com">Mike Gunderloy</a></p></div>
1180 </div>
1181
1182                 </div>
1183         </div>
1184 </body>
1185 </html>