Presented on 8/14/2012 at BostonRb. This talk provides a nice intro and overview of what RubyMotion is and whether or not it's worth incorporating into your development toolkit.

1. RubyMotion
iOS Development with Ruby
@markbates

4. I HATE iOS
DEVELOPMENT!

5. Why I Hate iOS Development

6. Why I Hate iOS Development
✦ XCode

7. Why I Hate iOS Development
✦ XCode
✦ Objective-C

8. Why I Hate iOS Development
✦ XCode
✦ Objective-C
✦ Cocoa/iOS APIs

18. XCode

23. Objective-C

24. # Create a new array (mutable):
myArray = %w{hello world etc}
myArray << "new value"
# Create a new hash (mutable):
myHash = {"key-a" => "value-a", "key-b" => "value-b"}
myHash["key-c"] = "value-c"

25. // Create a new array:
NSArray *myArray = [NSArray arrayWithObjects:@"hello",@"world",@"etc",nil];
// Create a mutable array:
NSMutableArray *myArray = [[NSMutableArray alloc] init];
[myArray addObject:@"hello world"];
// Create a dictionary (hash):
NSDictionary *myDictionary = [NSDictionary dictionaryWithObjectsAndKeys:
@"value-a", @"key-a", @"value-b", @"key-b", nil];
// Create a mutable dictionary:
NSMutableDictionary *myDictionary = [NSMutableDictionary dictionary];
[myDictionary setObject: @"value-c" forKey: @"key-c"];

26. now = -> {
puts "The date and time is: #{Time.now}"
}
now.call

27. void (^now)(void) = ^ {
NSDate *date = [NSDate date];
NSLog(@"The date and time is %@", date);
};
now();

28. Cocoa/iOS APIs

29. require 'net/http'
require 'json'
url = "http://www.example.com/api.json"
response = Net::HTTP.get_response(URI.parse(url))
if response.code.to_i == 200
json = JSON.parse(response.body)
puts json.inspect
else
puts "An Error Occurred (#{response.code}): #{response.body}"
end

30. - (void)viewDidLoad {
[super viewDidLoad];
responseData = [[NSMutableData data] retain];
NSURLRequest *request = [NSURLRequest requestWithURL:[NSURL URLWithString:@"http://www.example.com/api.json"]];
[[NSURLConnection alloc] initWithRequest:request delegate:self];
}
- (void)connection:(NSURLConnection *)connection didReceiveResponse:(NSURLResponse *)response {
[responseData setLength:0];
}
- (void)connection:(NSURLConnection *)connection didReceiveData:(NSData *)data {
[responseData appendData:data];
}
- (void)connection:(NSURLConnection *)connection didFailWithError:(NSError *)error {
label.text = [NSString stringWithFormat:@"Connection failed: %@", [error description]];
}
- (void)connectionDidFinishLoading:(NSURLConnection *)connection {
[connection release];
NSString *responseString = [[NSString alloc] initWithData:responseData encoding:NSUTF8StringEncoding];
[responseData release];
NSError *error;
SBJSON *json = [[SBJSON new] autorelease];
NSArray *myArray = [json objectWithString:responseString error:&error];
[responseString release];
if (myArray == nil)
label.text = [NSString stringWithFormat:@"JSON parsing failed: %@", [error localizedDescription]];
else {
NSMutableString *text = [NSMutableString stringWithString:@"Array Data:n"];
for (int i = 0; i < [myArray count]; i++)
[text appendFormat:@"%@n", [myArray objectAtIndex:i]];
label.text = text;
}
}

33. Laurent Sansonetti
✦ Worked for Apple for 7 years on iLife and
OS X
✦ Developed MacRuby
✦ Developed RubyCocoa
✦ Belgian

34. So What Does it Do?

35. So What Does it Do?
✦ Ruby!!! (NO OBJECTIVE-C!)

36. So What Does it Do?
✦ Ruby!!! (NO OBJECTIVE-C!)
✦ Keep Your Editor (NO XCODE!)

37. So What Does it Do?
✦ Ruby!!! (NO OBJECTIVE-C!)
✦ Keep Your Editor (NO XCODE!)
✦ IRB

38. So What Does it Do?
✦ Ruby!!! (NO OBJECTIVE-C!)
✦ Keep Your Editor (NO XCODE!)
✦ IRB
✦ Terminal Based Workflow (Rake)

39. So What Does it Do?
✦ Ruby!!! (NO OBJECTIVE-C!)
✦ Keep Your Editor (NO XCODE!)
✦ IRB
✦ Terminal Based Workflow (Rake)
✦ Testing Framework (MacBacon)

40. So What Does it Do?
✦ Ruby!!! (NO OBJECTIVE-C!) ✦ Native Applications
✦ Keep Your Editor (NO XCODE!)
✦ IRB
✦ Terminal Based Workflow (Rake)
✦ Testing Framework (MacBacon)

41. So What Does it Do?
✦ Ruby!!! (NO OBJECTIVE-C!) ✦ Native Applications
✦ Keep Your Editor (NO XCODE!) ✦ App Store Approved
✦ IRB
✦ Terminal Based Workflow (Rake)
✦ Testing Framework (MacBacon)

42. Suck it Objective-C!

43. NSString *urlAsString = @"http://www.apple.com";
NSURL *url = [NSURL URLWithString:urlAsString];
NSURLRequest *urlRequest = [NSURLRequest requestWithURL:url];
NSOperationQueue *queue = [[NSOperationQueue alloc] init];
[NSURLConnection
sendAsynchronousRequest:urlRequest
queue:queue
completionHandler:^(NSURLResponse *response,
NSData *data,
NSError *error) {
if ([data length] >0 &&
error == nil){
/* Get the documents directory */
NSString *documentsDir =
[NSSearchPathForDirectoriesInDomains(NSDocumentDirectory,
NSUserDomainMask,
YES) objectAtIndex:0];
/* Append the file name to the documents directory */
NSString *filePath = [documentsDir
stringByAppendingPathComponent:@"apple.html"];
/* Write the data to the file */
[data writeToFile:filePath
atomically:YES];
NSLog(@"Successfully saved the file to %@", filePath);
}
else if ([data length] == 0 &&
error == nil){
NSLog(@"Nothing was downloaded.");
}
else if (error != nil){
NSLog(@"Error happened = %@", error);
}
}];

44. url = NSURL.URLWithString("http://www.apple.com")
request = NSURLRequest.requestWithURL(url)
queue = NSOperationQueue.alloc.init
NSURLConnection.sendAsynchronousRequest(request,
queue: queue,
completionHandler: lambda do |response, data, error|
if(data.length > 0 && error.nil?)
doc_dir = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory,
NSUserDomainMask,
true).first
#p doc_dir
file_path = doc_dir.stringByAppendingPathComponent("apple.html")
data.writeToFile(file_path, atomically: true)
p "Saved file to #{file_path}"
elsif( data.length == 0 && error.nil? )
p "Nothing was downloaded"
elsif(!error.nil?)
p "Error: #{error}"
end
end)

45. But What About Those Weird
Named Argument Methods?

46. - (void)tableView:(UITableView *)tableView didSelectRowAtIndexPath:(NSIndexPath *)indexPath {
// do something
}
- (NSInteger)tableView:(UITableView *)tableView numberOfRowsInSection:(NSInteger)section {
// do something
}
- (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath {
// do something
}

47. def tableView(tableView, didSelectRowAtIndexPath: indexPath)
# do something
end
def tableView(tableView, numberOfRowsInSection: section)
# do something
end
def tableView(tableView, cellForRowAtIndexPath: indexPath)
# do something
end

48. Demo Time

49. Bubble Wrap
https://github.com/rubymotion/BubbleWrap

50. HTTP
data = {first_name: 'Matt', last_name: 'Aimonetti'}
BubbleWrap::HTTP.post("http://foo.bar.com/", {payload: data}) do |response|
if response.ok?
json = BubbleWrap::JSON.parse(response.body.to_str)
p json['id']
elsif response.status_code.to_s =~ /40d/
App.alert("Login failed")
else
App.alert(response.error_message)
end
end

51. App
> App.documents_path
# "~/iPhone Simulator/5.0/Applications/EEC6454E-1816-451E-BB9A-EE18222E1A8F/Documents"
> App.resources_path
# "~/iPhone Simulator/5.0/Applications/EEC64-1816-451E-BB9A-EE18221A8F/testSuite_spec.app"
> App.name
# "testSuite"
> App.identifier
# "io.bubblewrap.testSuite"
> App.alert("BubbleWrap is awesome!")
# creates and shows an alert message.
> App.run_after(0.5) { p "It's #{Time.now}" }
# Runs the block after 0.5 seconds.
> App.open_url("http://matt.aimonetti.net")
# Opens the url using the device's browser. (accepts a string url or an instance of NSURL.
> App::Persistence['channels'] # application specific persistence storage
# ['NBC', 'ABC', 'Fox', 'CBS', 'PBS']
> App::Persistence['channels'] = ['TF1', 'France 2', 'France 3']
# ['TF1', 'France 2', 'France 3']

52. Device
> Device.iphone?
# true
> Device.ipad?
# false
> Device.front_camera?
# true
> Device.rear_camera?
# true
> Device.orientation
# :portrait
> Device.simulator?
# true
> Device.retina?
# false
> Device.screen.width
# 320
> Device.screen.height
# 480
> Device.screen.width_for_orientation(:landscape_left)
# 480
> Device.screen.height_for_orientation(:landscape_left)
# 320

53. Camera
# Uses the front camera
BW::Device.camera.front.picture(media_types: [:movie, :image]) do |result|
image_view = UIImageView.alloc.initWithImage(result[:original_image])
end
# Uses the rear camera
BW::Device.camera.rear.picture(media_types: [:movie, :image]) do |result|
image_view = UIImageView.alloc.initWithImage(result[:original_image])
end
# Uses the photo library
BW::Device.camera.any.picture(media_types: [:movie, :image]) do |result|
image_view = UIImageView.alloc.initWithImage(result[:original_image])
end

54. JSON
BW::JSON.generate({'foo => 1, 'bar' => [1,2,3], 'baz => 'awesome'})
=> "{"foo":1,"bar":[1,2,3],"baz":"awesome"}"
BW::JSON.parse "{"foo":1,"bar":[1,2,3],"baz":"awesome"}"
=> {"foo"=>1, "bar"=>[1, 2, 3], "baz"=>"awesome"}

55. Media
# Plays in your custom frame
local_file = NSURL.fileURLWithPath(File.join(NSBundle.mainBundle.resourcePath, 'test.mp3'))
BW::Media.play(local_file) do |media_player|
media_player.view.frame = [[10, 100], [100, 100]]
self.view.addSubview media_player.view
end
# Plays in an independent modal controller
BW::Media.play_modal("http://www.hrupin.com/wp-content/uploads/mp3/testsong_20_sec.mp3")

56. Deferrables
> d = EM::DefaultDeferrable.new
=> #<BubbleWrap::Reactor::DefaultDeferrable:0x6d859a0>
> d.callback { |what| puts "Great #{what}!" }
=> [#<Proc:0x6d8a1e0>]
> d.succeed "justice"
Great justice!
=> nil

57. Events
> o = Class.new { include EM::Eventable }.new
=> #<#<Class:0x6dc1310>:0x6dc2ec0>
> o.on(:november_5_1955) { puts "Ow!" }
=> [#<Proc:0x6dc6300>]
> o.on(:november_5_1955) { puts "Flux capacitor!" }
=> [#<Proc:0x6dc6300>, #<Proc:0x6dc1ba0>]
> o.trigger(:november_5_1955)
Ow!
Flux capacitor!
=> [nil, nil]

58. More...
✦ Localization ✦ Location
✦ Color ✦ Gestures
✦ UUID Generator ✦ RSS Parser
✦ NSNotificationCenter ✦ Reactor
✦ Persistence ✦ Timers
✦ Observers
✦ String (underscore, camelize, etc...)

59. Pros & Cons

60. The Pros

61. The Pros
✦ Ruby!!

62. The Pros
✦ Ruby!!
✦ IDE Agnostic

63. The Pros
✦ Ruby!!
✦ IDE Agnostic
✦ “Wrapper” Gems

64. The Pros
✦ Ruby!!
✦ IDE Agnostic
✦ “Wrapper” Gems
✦ Fast

65. The Pros
✦ Ruby!!
✦ IDE Agnostic
✦ “Wrapper” Gems
✦ Fast
✦ IRB

66. The Pros
✦ Ruby!! ✦ Easy to test
✦ IDE Agnostic
✦ “Wrapper” Gems
✦ Fast
✦ IRB

67. The Pros
✦ Ruby!! ✦ Easy to test
✦ IDE Agnostic ✦ Growing community
✦ “Wrapper” Gems
✦ Fast
✦ IRB

68. The Pros
✦ Ruby!! ✦ Easy to test
✦ IDE Agnostic ✦ Growing community
✦ “Wrapper” Gems ✦ Frequent updates
✦ Fast
✦ IRB

69. The Cons

70. The Cons
✦ Cost - $199

71. The Cons
✦ Cost - $199
✦ Existing tutorials in Objective-C

72. The Cons
✦ Cost - $199
✦ Existing tutorials in Objective-C
✦ Maintainability?

73. The Cons
✦ Cost - $199
✦ Existing tutorials in Objective-C
✦ Maintainability?
✦ No Debugger (Yet)

74. The Cons
✦ Cost - $199
✦ Existing tutorials in Objective-C
✦ Maintainability?
✦ No Debugger (Yet)
✦ Difficult to work with Interface Builder

75. The Verdict

76. Resources
✦ http://www.rubymotion.com ✦ http://rubymotionapps.com/projects
✦ http://rubymotion-tutorial.com ✦ http://pragmaticstudio.com/screencasts/
rubymotion
✦ https://github.com/IconoclastLabs/
rubymotion_cookbook
✦ https://github.com/railsfactory/
rubymotion-cookbook
✦ https://twitter.com/RubyMotion
✦ http://rubymotionweekly.com