book

Ajax on Rails

by Scott Raymond

January 2007

Intermediate to advanced

350 pages

English

O'Reilly Media, Inc.

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Assumptions This Book MakesContents of This BookConventions Used in This BookUsing Code ExamplesWe’d Like to Hear from YouSafari® EnabledAcknowledgments
Who This Book Is ForWhat Ajax IsThe Traditional ModelThe Ajax ModelIt’s Actually Pretty EasyThe Eras of Web DevelopmentHistory of AjaxAjax: Neither Asynchronous nor XML. Discuss.What Rails IsRails Mantras‘You Got Your Ajax in My Rails!’Getting Up to SpeedStarting RubyGetting on the RailsOther Things You’ll WantHello, RailsRails Writ LargeSummary
The Old-Fashioned WayStarting a ProjectJavaScript Libraries and PrototypeBringing Rails into the PictureERb BasicsLayoutsPartialsHelpersBack to AjaxSummary
Setting the StageAjax LinksCallbacksOther OptionsLinking to an arbitrary functionFormsForm Tag HelpersForm HelpersUsing form_forAjax FormsButtonsButtons for Arbitrary FunctionsCustom HelpersForm ObserversObserving an Entire FormSummary
Visual EffectsTogglingOptionsQueuesCallbacksTransitionsVisual Effect HelperDrag and DropDraggablesDraggable optionsDroppablesDroppable optionsDroppables with AjaxSortablesAjax-enabled sortablesSummary
Instructions Instead of DataPutting the R in RJSDiving InRendering JavaScript Without RJSRJS: Generating JavaScript with RubyUsing .rjs filesTesting and debugging RJSElement ProxiesCustom methods with element proxiesUpdating content with element proxiesreplace_html and replacereloadCollection Proxieseachinvokepluckcollect/mapdetect/findselect/find_allrejectpartitionmin and maxall and anyinjectzipsort_byJavaScriptGenerator MethodsManipulating DOM elementsInserting contentRedirectingDelaying executionCreating drag-and-drop elementsGenerating arbitrary JavaScriptClass proxiesRJS HelpersRJS Without AjaxA Real-World ExampleThe Old WayThe RJS WaySummary
Principles of UsabilityPersonal Assistant: Defending AttentionTour Guide: Manage ExpectationsUser models and program modelsExample: Windows versus Mac program modelsSet accurate expectationsMentor: Design Not Just for Usability, but LearnabilityTeach with affordancesTrainer: Provide Immediate FeedbackDirect manipulationWork with the mindUse color appropriatelyThe Context of the WebHTTPThe PageUsability on the WebKnow When to Use Ajax—and When Not ToDon’t break the back buttonDon’t use Ajax for navigationKeep Page Elements ConsistentKey CommandsIncreasing Responsiveness with Ajax (‘It’s Too Slow!’)Consequences of Increased Responsiveness (‘It’s Too Fast!’)Blank Slates, Coach Content, and Help NuggetsBlank slatesCoach contentHelp nuggetsCross-Platform DevelopmentRealities of PlatformsWhat makes a platformIt isn’t all badDealing with platform differencesThe Rails WayKnow your audienceGraceful Degradation and Progressive EnhancementSummary
DebuggingUnderstanding Rails ExceptionsUsing the Development LogInteractive ConsolesUsing IrbUsing the Rails console with ActiveRecordUsing the Rails console with ActionPackRails breakpointsInspectorsUsing the debug helperRJS debugging modeRouting NavigatorFireBugTestingFunctional TestsTesting RJSTesting HTML ValidityIntegration TestsJavaScript Unit TestingSummary
Healthy Skepticism: Don’t Trust User InputUsing Scoped QueriesRecord IDs in URLsMass AssignmentForm ValidationSQL InjectionSession FixationCross-Site ScriptingHashing PasswordsSilencing LogsThe Same-Origin PolicyCreating an Ajax ProxyBypassing XMLHttpRequest for Cross-Domain RequestsThe Use and Abuse of HTTP MethodsEncryption and Secure CertificatesAjax over SSLThe Rails Security Mailing ListSummary
Development and Production EnvironmentsSession StoresActiveRecordStoreSQLSessionStorememcachedTurning Sessions OffOutput CachingPage CachingAction CachingFragment CachingExpiring Output CachesAsset PackagingDealing with Long-Running TasksSummary
Ajax SupportBase ObjectsAjax RequestsAjax.Request optionsExamplesAjax UpdatersAjax.Updater optionsExamplesPeriodical Ajax UpdatersAjax.PeriodicalUpdater optionsExampleGlobal RespondersExampleDOM Manipulation$()$F()SelectorsExamplesdocument.getElementsByClassName(className [, parentElement])Element Methodsclass Element.ClassNamesInserting Contentclass Insertion.Beforeclass Insertion.Topclass Insertion.Bottomclass Insertion.AfterExamplesElement PositioningForm ObserversCore ExtensionsArray ExtensionsHashesRangesExampleEnumerableString ExtensionsString TemplatesNumber ExtensionsEventsFunction ExtensionsExampleObject ExtensionsClassesPeriodicalExecuterExampleTry.these()Prototype
Visual EffectsCore EffectsCombination EffectsEffect OptionsEffect Instance Methods and PropertiesEffect TransitionsEffect CallbacksEffect QueuesStatic Effect MethodsDrag and Dropclass DraggableExamplesInstance methods and propertiesDraggablesDroppable ElementsSortable ElementsControlsAuto-CompletionStandard optionsLocal auto-completingExampleAjax auto-completionExampleIn-Place EditorsOptions ExamplesInstance methodsSlidersExamplesInstance methodsElement ExtensionsDOM BuilderJavaScript Unit TestingAssertionsUtility Methods

Overview

Learn to build dynamic, interactive web applications using the two most important approaches to web development today: Ajax and the phenomenally efficient Ruby on Rails platform. This book teaches intermediate to advanced web developers how to use both Ajax and Rails to quickly build high-performance, scalable applications without being overwhelmed with thousands of lines of JavaScript code. More than just recipes, you also get a thorough, low-level understanding of what's happening under the hood.

Ajax on Rails includes three fully worked out Rails/Ajax applications, and quick reference sections for Prototype and script.aculo.us.
Testing lessons show you how to eliminate cross-browser JavaScript errors and DOM debugging nightmares using a combination of Firebug, and Venkman.
Advanced material explains the most current design practices for Ajax usability. You'll learn to avoid user experience mistakes with proven design patterns.

Beyond the how-to, Ajax on Rails helps you consider when Ajax is (and isn't) appropriate, and the trade-offs associated with it. For those new to Rails, this book provides a quick introduction, the big picture, a walk through the installation process, and some tips on getting started. If you've already started working with Rails and seek to deepen your skill set, you'll find dozens of examples drawn from real-world projects, exhaustive reference for every relevant feature, and expert advice on how to "Ajaxify" your applications.