aaronh/bubblewrap

Cocoa wrappers and helpers for RubyMotion (Ruby for iOS) - Making Cocoa APIs more Ruby like, one API at a time. Fork away and send your pull requests.

BubbleWrap for RubyMotion

A collection of (tested) helpers and wrappers used to wrap CocoaTouch code and provide more Ruby like APIs.

BubbleWrap website BubbleWrap mailing list

Installation

gem install bubble-wrap

Setup

1. Edit the Rakefile of your RubyMotion project and add the following require line:

require 'bubble-wrap'

BubbleWrap is split into multiple modules so that you can easily choose which parts are included at compile-time.

The above example requires the core and http modules. If you wish to only include the core modules use the following line of code instead:

require 'bubble-wrap/core'

If you wish to only include the HTTP wrapper:

require 'bubble-wrap/http'

If you wish to only include the RSS Parser wrapper:

require 'bubble-wrap/rss_parser'

If you wish to only include the Reactor wrapper:

require 'bubble-wrap/reactor'

If you want to include everything (ie kitchen sink mode) you can save time and do:

require 'bubble-wrap/all'

Note: DON'T use app.files = in your Rakefile to set up your files once you've required BubbleWrap. Make sure to append onto the array or use +=.

2. Now, you can use BubbleWrap extension in your app:

class AppDelegate
  def application(application, didFinishLaunchingWithOptions:launchOptions)
    puts "#{App.name} (#{App.documents_path})"
    true
  end
end

Note: You can also vendor this repository but the recommended way is to use the versioned gem.

Core

App

A module with useful methods related to the running application

> App.documents_path
# "/Users/mattetti/Library/Application Support/iPhone Simulator/5.0/Applications/EEC6454E-1816-451E-BB9A-EE18222E1A8F/Documents"
> App.resources_path
# "/Users/mattetti/Library/Application Support/iPhone Simulator/5.0/Applications/EEC6454E-1816-451E-BB9A-EE18222E1A8F/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']

Other available methods:

• App.notification_center
• App.user_cache
• App.states
• App.frame
• App.delegate
• App.current_locale

Device

A collection of useful methods about the current device:

Examples:

> 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

Gestures

Extra methods on UIView for working with gesture recognizers. A gesture recognizer can be added using a normal Ruby block, like so:

    view.whenTapped do
      UIView.animateWithDuration(1,
        animations:lambda {
          # animate
          # @view.transform = ...
        })
    end

There are similar methods for pinched, rotated, swiped, panned, and pressed (for long presses). All of the methods return the actual recognizer object, so it is possible to set the delegate if more fine-grained control is needed.

JSON

BubbleWrap::JSON wraps NSJSONSerialization available in iOS5 and offers the same API as Ruby's JSON std lib.

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"}

NSIndexPath

Helper methods added to give NSIndexPath a bit more of a Ruby interface.

NSNotificationCenter

Helper methods to give NSNotificationCenter a Ruby-like interface:

def viewWillAppear(animated)
  @foreground_observer = notification_center.observe UIApplicationWillEnterForegroundNotification do |notification|
    loadAndRefresh
  end
  
  @reload_observer = notification_center.observe ReloadNotification do |notification|
    loadAndRefresh
  end
end

def viewWillDisappear(animated)
  notification_center.unobserve @foreground_observer
  notification_center.unobserve @reload_observer
end

def reload
  notification_center.post ReloadNotification
end

NSUserDefaults

Helper methods added to the class repsonsible for user preferences used by the App::Persistence module shown below.

Persistence

Offers a way to persist application specific information using a very simple interface:

> 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']

Observers

Since: > version 0.4

You can observe for object's changes and trigger blocks:

class ExampleViewController < UIViewController
  include BW::KVO

  def viewDidLoad
	@label = UILabel.alloc.initWithFrame [[20,20],[280,44]]
	@label.text = ""
	view.addSubview @label
	
    observe(@label, "text") do |old_value, new_value|
      puts "Hello from viewDidLoad!"
    end
  end

  def viewDidAppear(animated)
    observe(@label, "text") do |old_value, new_value|
      puts "Hello from viewDidAppear!"
    end
  end

end

String

The Ruby String class was extended to add #camelize and #underscore methods.

> "matt_aimonetti".camelize
=> "MattAimonetti"
> "MattAimonetti".underscore
=> "matt_aimonetti"

Time

The Time Ruby class was added a class level method to convert a iso8601 formatted string into a Time instance.

> Time.iso8601("2012-05-31T19:41:33Z")
=> 2012-05-31 21:41:33 +0200

UIControl / UIButton

Helper methods to give UIButton a Ruby-like interface. Ex:

button.when(UIControlEventTouchUpInside) do
  self.view.backgroundColor = UIColor.redColor
end

UIViewController

A custom method was added to UIViewController to return the content frame of a view controller.

HTTP

BubbleWrap::HTTP wraps NSURLRequest, NSURLConnection and friends to provide Ruby developers with a more familiar and easier to use API. The API uses async calls and blocks to stay as simple as possible.

To enable it add the following require line to your Rakefile:

require 'bubble-wrap/http'

Usage example:

BubbleWrap::HTTP.get("https://api.github.com/users/mattetti") do |response|
  p response.body.to_str
end

BubbleWrap::HTTP.get("https://api.github.com/users/mattetti", {credentials: {username: 'matt', password: 'aimonetti'}}) do |response|
  p response.body.to_str # prints the response's body
end

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 =~ /40\d/
    App.alert("Login failed")
  else
    App.alert(response.error_message)
  end
end

RSS Parser

Since: > version 1.0.0

The RSS Parser provides an easy interface to consume RSS feeds in an asynchronous (non blocking) way.

feed_parser = BW::RSSParser.new("http://feeds2.feedburner.com/sdrbpodcast")
feed_parser.parse do |item|
  # called asynchronously as items get parsed
  p item.title
end

The yielded RSS item is of type RSSParser::RSSItem and has the following attributes:

• title
• description
• link
• guid
• pubDate
• enclosure

The item can be converted into a hash by calling to_hash on it.

Delegate

Since: > version 1.0.0

You can also designate a delegate to the parser and implement change state callbacks:

feed_parser = BW::RSSParser.new("http://feeds.feedburner.com/sdrbpodcast")
feed_parser.delegate = self
feed.parse do |item|
  p item.title
end

# Delegate method
def when_parser_initializes
  p "The parser is ready!"
end

def when_parser_parses
  p "The parser started parsing the document"
end

def when_parser_is_done
  p "The feed is entirely parsed, congratulations!"
end

These delegate methods are optional, however, you might find the when_parser_is_done callback useful if you collected all the items and want to process all at once for instance.

Parsing a remote content or actual data

You have the choice to initialize a parser instance with a string representing an URL, an instance of NSURL or my specifying that the passed param is some data to parse directly.

# string representing an url:
feed_parser = BW::RSSParser.new("http://feeds2.feedburner.com/sdrbpodcast")
# a NSURL instance:
url =  NSURL.alloc.initWithString("http://matt.aimonetti.net/atom.xml")
feed_parser = BW::RSSParser.new(url)
# Some data
feed = File.read('atom.xml')
feed_parser = BW::RSSParser.new(feed, true)

Reactor

Since: > version 1.0.0

BubbleWrap::Reactor is a simplified, mostly complete implementation of the Event Machine API. In fact BubbleWrap::Reactor is aliased to EM in the runtime environment.

Deferables

BubbleWrap provides both a Deferrable mixin and a DefaultDeferrable class, which simply mixes in deferrable behaviour if you don't want to implement your own.

A deferrable is an object with four states: unknown, successful, failure and timeout. When you initially create a deferrable it is in an unknown state, however you can assign callbacks to be run when the object changes to either successful or failure state.

Success

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

Failure

> d = EM::DefaultDeferrable.new
=> #<BubbleWrap::Reactor::DefaultDeferrable:0x8bf3ee0>
> d.errback { |what| puts "Great #{what}!" }
=> [#<Proc:0x8bf3ef0>]
> d.fail "sadness"
Great sadness!
=> nil

Timeout

> d = EM::DefaultDeferrable.new
=> #<BubbleWrap::Reactor::DefaultDeferrable:0x8bf5910>
> d.errback { puts "Great scott!" }
=> [#<Proc:0x8bf6350>]
> d.timeout 2
=> #<BubbleWrap::Reactor::Timer:0x6d920a0 @timer=#<__NSCFTimer:0x6d91990>>
# wait...
> Great scott!

Timers

All timers can be cancelled using EM.cancel_timer.

One-shot timers

> EM.add_timer 1.0 do
>   puts "Great scott!"
> end
=> 146335904
> Great scott!

Periodic timers

> count = 0
=> 0
> timer = EM.add_periodic_timer 1.0 do
>   count = count + 1
>   puts "Great scott!"
>   (count < 10) || EM.cancel_timer(timer)
> end
=> 146046832
> Great scott!
Great scott!
Great scott!
Great scott!
Great scott!
Great scott!
Great scott!
Great scott!
Great scott!
Great scott!

Scheduling operations

You can use EM.schedule to schedule blocks to be executed asynchronously. BubbleWrap deviates from the EventMachine API here in that it also provides EM.schedule_on_main which makes sure that the task is run asynchronously, but on the application's main thread - this is necessary if you are updating the user interface.

> EM.schedule { puts Thread.current.object_id }
146027920
=> nil
> EM.schedule_on_main { puts Thread.current.object_id }
112222480
=> nil

Deferrable operations

You can also use EM.defer in much the same way as EM.schedule with one important difference, you can pass in a second proc which will be called when the first has completed, and be passed it's result as an argument:

> operation = proc { 99 }
=> #<Proc:0x6d763c0>
> callback = proc { |speed| puts speed >= 99 ? "Time travel!" : "Conventional travel!" }
=> #<Proc:0x8bd3910>
> EM.defer(operation, callback)
=> nil
Time travel!

Events

Although not part of the EventMachine API, BubbleWrap provides an Eventable mixin for use instrumenting objects with simple event triggering behaviour. BubbleWrap::Reactor uses this behind the scenes in several places, and as it's a very handy idiom it is available as a public API.

> 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]

Suggestions?

Do you have a suggestion for a specific wrapper? Feel free to open an issue/ticket and tell us about what you are after. If you have a wrapper/helper you are using and are thinking that others might enjoy, please send a pull request (with tests if possible).