Objective-C vs. RubyMotion!

Presented at ChicagoRuby, Jan 8 2013.

Transcript

2. VS OBJECTIVE-C RUBYMOTION
3. David Demaree Typekit UX & Ruby engineer at Adobe @ddemaree log.demaree.me ddemaree@gmail.com   ✉
4. Objective-C Invented in 1983, adopted by NeXT, currently maintained by Apple Pretty much used only for Apple platforms Statically typed object- oriented language Strict superset of C Preprocessed
5. RubyMotion Implementation of Ruby 1.9 (sort of) on LLVM and the Objective-C runtime Closed-source compiler, available commercially for $199 (+ annual support fee) Open-source build tools, based on Rubygems and Rake
6. WHY IS RUBYMOTION BETTER THAN ___?
9. iOS Developer Agreement 3.3.1 Applications may only use Documented APIs in the manner prescribed by Apple and must not use or call any private APIs. Applications must be originally written in Objective-C, C, C++, or JavaScript as executed by the iPhone OS WebKit engine, and only code written in C, C++, and Objective-C may compile and directly link against the Documented APIs (e.g., Applications that link to Documented APIs through an intermediary translation or compatibility layer or tool are prohibited).
10. iOS Developer Agreement 3.3.1 Applications may only use Documented APIs in the manner prescribed by Apple and must not use or call any private APIs. Applications must be originally written in Objective-C, C, C++, or JavaScript as executed by the iPhone OS WebKit engine, and only code written in C, C++, and Objective-C may compile and directly link against the Documented APIs (e.g., Applications that link to Documented APIs through an intermediary translation or compatibility layer or tool are prohibited).
11. Ruby source code ObjC libraries Cocoa frameworks Native iOS app RubyMotion calls Cocoa frameworks directly
12. PhoneGap app (HTML/CSS/JS) Objective-C runtime Cocoa app (Objective-C) Cocoa app (RubyMotion) Compiles to Obj-C bytecode Compiles to Obj-C bytecode PhoneGap cross-platform runtime
13. Apple
14. 5by5.tv/hypercritical/66
15. CODE
16. VS Objective-C Ruby syntax
17. CAUTION Now entering nerd zone
18. In the beginning, there was OBJECTIVE-C RUBY PYTHON JAVA SCALA GROOVY SMALLTALK
19. Learning Objective-C Programming with Objective-‐C bit.ly/objcprimer apeth.com/iOSBook cocoabook.com
20. Learning Ruby & RubyMotion All titles available at pragprog.com
21. Statically compiled No require No eval No Proc#binding No define_method Named parameters RubyMotion !≈ Ruby
22. Objective-C
23. Classic Obj-C Modern Obj-C Brackets everywhere Properties & dot syntax Verbose code for working with basic object types Object literals Manual memory management ARC No blocks Blocks!
24. Objective-C
25. Ruby can do almost anything Obj-C can do, BUT SIMPLER
26. @interface DDVenue : NSObject @property (strong) NSString *name; @property (strong) NSString *address; @property (strong) CLLocation *location; - (CLLocationDistance)distanceFromLocation:(CLLocation *)otherLocation; @end @implementation DDVenue @synthesize name, address, location; - (CLLocationDistance)distanceFromLocation:(CLLocation *)otherLocation { return [self.location distanceFromLocation:otherLocation]; } @end
27. class Venue attr_accessor :name, :address, :location def distanceFromLocation(location) self.location.distanceFromLocation(location) end end
28. class Venue attr_accessor :name, :address, :location def distanceFromLocation(location) self.location.distanceFromLocation(location) end end Everything inherits from (NS)Object
29. class Venue attr_accessor :name, :address, :location def distanceFromLocation(location) self.location.distanceFromLocation(location) end end Everything inherits from (NS)Object Dynamic/“duck” typing
30. class Venue attr_accessor :name, :address, :location def distanceFromLocation(location) self.location.distanceFromLocation(location) end end Everything inherits from (NS)Object Dynamic/“duck” typing Implicit return
31. class Venue attr_accessor :name, :address, :location def distanceFromLocation(location) self.location.distanceFromLocation(location) end end Everything inherits from (NS)Object Dynamic/“duck” typing Implicit return All dot syntax, all the time
32. class Venue attr_accessor :name, :address, :location def distanceFromLocation(location) self.location.distanceFromLocation(location) end end Everything inherits from (NS)Object Dynamic/“duck” typing Implicit return All dot syntax, all the time No interface file required
33. @interface DDFood : NSObject { BOOL isPizza; } - (void)setIsPizza:(BOOL)value; @end @implementation DDFood - (void)setIsPizza:(BOOL)value { isPizza = value; } @end class Food def isPizza=(pizzaness) @isPizza = pizzaness end def isPizza! @isPizza = true end def isPizza? @isPizza ||= false end end Instance vars must be declared Anything with an @-sigil is an ivar
34. // YellingString.rb class String def yell self + "!" end end "Kind of awesome".yell.yell.yell #=> "Kind of awesome!!!" // NSString+Yelling.h @interface NSString (Yelling) - (NSString*) yell; @end // NSString+Yelling.m @implementation NSString (Yelling) - (NSString*) yell { return [self stringByAppendingString:@"!"]; } @end [@"Kind of awesome" yell]; //=> @"Kind of awesome!" Classes extended via categories Classes can be reopened at any time
35. Ruby has real namespaces NSString, GBFont, DDCoreDataManager MyApp::Venue, MyApp::Item, CoreData::Manager Objective-C class names are prefixed Ruby classes/modules can be nested inside each other
36. Multiple inheritance via mixins module StaticTableViewController CellInfo = Struct.new(:text, :accessory_type, :action) def tableView(tableView, cellForRowAtIndexPath:indexPath) cell = self.infoForCells[indexPath.row] # Create and return a UITableViewCell end end module SettingsViewController < UITableViewController include StaticTableViewController end
37. class Thing < Struct.new(:name) def has_hat? false end end module Hat def has_hat? true end end
38. myThing = Thing.new("Cat") myThing.has_hat? #=> false myThing.extend(Hat) myThing.has_hat? #=> true
39. Blocks! class PlaceFinder def self.placeFinderWithBlock(&block) newFinder = self.alloc.init yield newFinder if block_given? return newFinder end end @finder = PlaceFinder.placeFinderWithBlock do |finder| finder.location = CLLocation.alloc.initWithLatitude(lat, longitude:lng) finder.numberOfResults = 10 end
40. HTTP.get("http://github.com/ddemaree") do |response| p response.body.to_str # prints the response's body end @singleton = nil Dispatch.once do @singleton ||= self.alloc.initWithOptions({}) end Providing a completion callback for a HTTP request Initializing a singleton in a thread-safe way
41. WHAT’S SO GREAT ABOUT SIMPLER?
42. Less boilerplate
43. Code is easier to read and more self-documenting
44. It… feels good?
45. What do we give up by using RubyMotion?
46. No compile-time warnings
47. No direct access to the C layer
48. Enums and C structs typedef NS_ENUM(NSUInteger, GBListSettingsSection){ GBListSettingsBudgetToggleSection, GBListSettingsSectionLock, GBListSettingsSectionEmail, GBListSettingsSectionAll }; - (NSInteger)tableView:(UITableView *)tableView numberOfRowsInSection:(NSInteger)section { if (section == GBListSettingsBudgetInclusionSection) { return 2; } } - (NSInteger)numberOfSectionsInTableView:(UITableView *)tableView { return GBListSettingsSectionAll; }
49. class PlacesViewController < UITableViewController SECTIONS = [:budget, :lock, :email] def tableView(tableView, numberOfRowsInSection:section) sectionName = SECTIONS[section] if sectionName == :budget return 2 end end def numberOfSectionsInTableView(tableView) SECTIONS.length end end
50. The Uncanny Valley
51. > motion ri UIView RubyMotion `ri` documentation
52. RubyMotion’s “C” layer
53. RubyMotion’s C-like APIs Dispatch.once { @singleton ||= self.new } errorPtr = Pointer.new(:object) ABAddressBookCreateWithOptions(nil, errorPtr) Pointers are objects Functions are wrapped as methods on the Object class Grand Central Dispatch is wrapped as the Dispatch module
54. “Sexy” DSLs
55. Covering all of Cocoa with newer, simpler DSL abstractions is a stated goal of RubyMotion’s creators
57. alert = UIAlertView.alloc.initWithTitle "Hey, buddy", message: "Buzz off!", delegate: nil, cancelButtonTitle: nil, otherButtonTitles: nil alert.show() App.alert("Hey, buddy", message: "Buzz off!") do |alert| # You can perform any additional configuration on the # UIAlertView object here, using the `alert` variable end BubbleWrap Standard Cocoa API (in RubyMotion)
58. github.com/alloy/MotionData
59. PhoneGap app (HTML/CSS/JS) Objective-C runtime Cocoa app (Objective-C) Cocoa app (RubyMotion) Compiles to Obj-C bytecode PhoneGap cross-platform runtime RubyMotion DSLs?
60. TOOLS
61. VS Bring your own Xcode
62. VS Familiar (if you’re coming from Ruby/open-source development) Lighter-weight, which can be faster / more nimble Have it your way Supported by Apple Designed specifically for Cocoa/Cocoa Touch app development Excellent integrated documentation & code completion
63. Xcode knows more about Cocoa & Objective-C than most of us will ever forget
64. Context-sensitive code completion
65. Integrated documentation
66. Real-time error checking (via static analysis)
67. “Using XCode is like driving a very used, modern car - it routinely breaks down, freezes and screws up the rest of my system and there is no way to understand what it wrong because all the parts are hidden from you. For example, it will stop compiling and simply freeze, acting like it's doing something. It will kill other processes and cause them to freeze (terminal processes simply stop getting cycles). It will stop responding to step over, step in, etc actions. “If there is any way for you to avoid XCode, do so. So far, I have had to force quit 4 times since 9:00 AM.”
68. better? Is
69. > motion create my_project
70. Motion::Project::App.setup do |app| # Use `rake config' to see complete project settings. app.name = 'GiftBox' app.version = "2.0" app.interface_orientations = [:portrait] app.identifier = "me.demaree.GiftBox2" app.short_version = "190" app.frameworks += ["CoreData"] end RubyMotion configuration DSL
74. github.com/mattt/shenzhen
75. TESTING
76. TESTING ON IOS
77. Client-side applications are big, messy balls of SHARED STATE
78. iOS client-side testing ≈ Full-stack JavaScript testing?
79. QUESTIONS
80. Should I learn Cocoa on Objective-C first, or RubyMotion?
81. Learn Objective-C Because it’s awesome (really)
82. Learning Objective-C Programming with Objective-‐C bit.ly/objcprimer apeth.com/iOSBook cocoabook.com
84. If you use RubyMotion, try to at least learn the Cocoa APIs
85. Should I use RubyMotion?
86. How I use RubyMotion today Personal projects Rapid prototyping Internal apps?
87. Your questions
88. David Demaree Typekit UX & Ruby engineer at Adobe @ddemaree log.demaree.me ddemaree@gmail.com   ✉