This document provides an overview of EzSMS, a simple SMS gateway application for Android built using Ruby. It discusses why SMS is a useful communication method, introduces some key aspects of building Android applications like activities and intents, and provides a high-level look at how Ruboto allows Ruby scripts to be packaged and run as Android applications by mapping the underlying Android APIs. It also shares some limitations of using JRuby and Ruboto on Android.

1. EzSMS
A simple SMS gateway for Android
in Ruby
Chandan Jog
Habibullah Pagarkar
Anand Agrawal

2. Chandan Jog
@jog_chandan
cjog@thoughtworks.com

3. Habibullah Pagarkar
@mhabibp
hulk@thoughtworks.com

4. Intended Take-Aways
Why SMS?
Your options for building an SMS based app
Quick introduction to Android
A taste of Ruby on Android

5. SMS is omnipresent
Logical choice and not a “hot new”
technology
Caters to the technically un-savvy

6. SMS is powerful
MOTECH and mHealth
Suite of services
Basic mobile phones
Antenatal and neonatal care

7. SMS is useful

8. In the cloud

9. Or, deal with them

10. DIY

11. http://socialwebdaily.com/wp-content/uploads/2011/12/grandma_meme_large1.jpg
Can your grandma get it up?

12. We <3

13. We <3

14. http://walyou.com/android-exploded-shirt/
Anatomy of an Android app

15. Linux, but not quite
Linux kernel + Dalvik VM
No X. No GNU libraries. No JVM.

16. Activities
Visual components

17. Activities
An application consists of multiple
loosely coupled Activities

18. Activities
An Activity is notified of change in state
through application
life-cycle callbacks

19. Views and Layouts
Views and Widgets
Layout

20. publ i c class Exam eAc t i vi t y extends Act i vi t y {
s pl s
@Override e
publ i c void onCreate(Bundl e savedInstanceState) {
d )
s uper .onCreate(savedInstanceState); ;
}
@Override e
pr ot ect ed void onStart() {
d d )
s uper .onStart();
;
}
@Override e
pr ot ect ed void onResume() {
d d )
s uper .onResume();
;
}
@Override e
pr ot ect ed void onPause() {
d d )
s uper .onPause();
;
}
@Override e
pr ot ect ed void onStop() {
d d )
s uper .onStop();
;
}
@Override e
pr ot ect ed void onDestroy() {
d d
s uper .onDestroy();
;
) Activity
}
}

21. Intent
Roughly analogous to a message

22. Intent
Use Intents to communicate
within components of an application
or between applications

23. Intent
I nt ent intent = new Intent(I nt ent .ACTION_SEND);
t t w ;
intent.putExtra(I nt ent .EXTRA_EMAIL, recipientArray);
, ;
startActivity(intent);
;

24. Intent Filters
Explicit Intents
Designate a target component by its name
Implicit Intents
Do not name a target

25. Manifest
AndroidManifest.xml
Declaratively specify application
components, services, permissions,
minimum Android API version etc.

26. <manifest xmlns:android="http://schemas.android.com/apk/res/android"
package="com.example.android.notepad">
<application android:icon="@drawable/app_notes"
android:label="@string/app_name" >
<provider android:name="NotePadProvider"
android:authorities="com.google.provider.NotePad" />
<activity android:name="NotesList"
android:label="@string/title_notes_list">
<intent-filter>
<action android:name="android.intent.action.MAIN" />
<category android:name="android.intent.category.LAUNCHER" />
</intent-filter>
<intent-filter>
<action android:name="android.intent.action.VIEW" />
<action android:name="android.intent.action.EDIT" />
<action android:name="android.intent.action.PICK" />
<category android:name="android.intent.category.DEFAULT" />
<data android:mimeType="vnd.android.cursor.dir/vnd.google.note" />
</intent-filter>
<intent-filter>
<action android:name="android.intent.action.GET_CONTENT" />
<category android:name="android.intent.category.DEFAULT" />
<data android:mimeType="vnd.android.cursor.item/vnd.google.note" />
</intent-filter>
</activity>
</application>
</manifest>

27. Service
BroadcastReceiver
ContentProvider
…

28. Open
DBAdapter.java

29. http://awesomebmovies.com/2011/04/bill-and-teds-back-in-action/
It’s like, too much code, dude!
Whoa!

30. options_from_collection_for_select

31. Konnichiwa, Ruboto-san
Aims to make JRuby a first class Android
citizen
Lends to easy scripting
Maps underlying Android layer

32. Flavour 1
ruboto-irb
Interactive environment on the phone

34. Flavour 2
ruboto-core
Packages Ruby scripts as an APK

35. Pre-reqs
JRuby
Android SDK
Ruboto

36. Application Generator
$ ruboto gen app
--package com.yourdomain.whatever
--path path/to/app
--name AppName
--target android-version
--min-sdk another-android-version
--activity MainActivityName

37. Class Generator
$ ruboto gen class
BroadcastReceiver --name
AwesomenessReceiver

38. Packaging Tasks
$ rake install
$ rake update_scripts
$ rake install:clean
And many more with rake -T

39. Poll Box
A simple feedback gathering application
http://Poll-Box.com

40. http://www.caribdirect.com/2012/01/31/hows-my-driving-too-fast-too-bad/
How are we doing?

41. SMS 08800493714
code Y/N comment
ezsms Y The talk is awesome!

42. poll-box.com/response/102/ezsms

43. http://en.wikipedia.org/wiki/Linus_Torvalds
Talk is cheap
the code
We’ll show you

44. Fork it
github.com/chandanjog/ez_sms

45. Good news everyone!
http://hollywoodhatesme.files.wordpress.com/2011/09/prof-farnsworth.jpg
Use your existing Ruby knowledge
Type less ;)
Best of both worlds
Android APIs
RubyGems

46. Bad News
JRuby isn’t designed for constrained devices
Stack space limitations on the Dalvik VM
Ruboto doesn’t completely abstract away
Android’s complexities
Slow JRuby start-up time