Refactoring:Improving the Design of Existing Code

Watch for warning signs in your own code –- that is "code smells" !!!

The Lunch 'N Learn session really did not start with that line, but that is the most important guideline in refactoring.


Every Lunch 'N Learn Sessions is something to look forward to hmmmm free lunch? Well you may think it is but there is something more to it, lots of ideas were shared during these small talks from the Exist Gurus and this time it's one of Exist best, Ms. Deng.


What is Refactoring? Ms. Deng, gives quite an opening through asking a question.
Everybody seems dumbstruck, well maybe because it's the first time that the participants are being asked early in the discussion even before they can do so or they are just quiet familiar with the word or they're full of ideas? I bet they have been refactoring all there programming life, everybody does right?


What really is Refactoring?
Refactoring is a disciplined technique for restructuring an existing body of code, altering its internal structure without changing its external behavior.

Its heart is a series of small behavior preserving transformations. Each transformation (called a 'refactoring') does little, but a sequence of transformations can produce a significant restructuring.

Why should you refactor?
– Refactoring improves the design of software
– Refactoring makes software easier to understand
– Refactoring helps you find bugs
– Refactoring helps you program faster

But when should you refactor?
– Refactor when you add a function
– Refactor when you need to fix a bug
– Refactor when you do a code review

In short refactor when your system changes otherwise its pointless, refactoring a changing software so it can be easily changed in the future gives you a payback.
Take note when you refactor you should also test, testing is very important underpinning to refactoring, as Fowler says:
“Think of it as walking a tightrope without a net. If you are good at walking a tightrope, and it's not that high up, then you might try it. But if you've never walked a tightrope before, and it's over Niagara Falls, you probably want a good net.”

Code smells or code that smells bad.

• Duplicated Code
• Long Method
• Large Class
• Long Parameter List
• Divergent Change
• Shotgun Surgery
• Feature Envy
• Data Clumps
• Primitive Obsession
• Switch Statements
• Parallel Inheritance Hierarchies
• Lazy Class
• Speculative Generality
• Temporary Field
• Message Chains
• Middle Man
• Inappropriate Intimacy
• Alternative Classes with Different Interfaces
• Incomplete Library Class
• Data Class
• Refused Bequest
• Comments

Listed above are just the 22 code smells, but there are 73 code smell refactorings in 7 categories.

Lazy Class

A class that isn't doing enough to pay for itself should be eliminated. A class isn't doing very much.

Move all its features into another class and delete it. Useless components are subjected to Inline Class.

Extract Hierarchy

You have a class that is doing too much work, at least in part through many conditional statements.

Create a hierarchy of classes in which each subclass represents a special case.

For more on refactoring read:
Refactoring:Improving the Design of Existing Code by Martin Fowler


“Any fool can write code that a computer can understand. Good programmers write code that humans can understand.”

MySpace Soft Launch!!!

Few weeks ago (February 5) they had launched MDP (Myspace Developer Platform) to developers for them to play with the OpenSocial API and MySpace's Platform. So its dev facing MySpace/OpenSocial. And promise to go live to MySpace end-users after a month, this time MySpace end-users facing MySpace 3rd party Apps.

Tomorrow, March 13, 2008 (Thursday), MySpace will be

having a DevJam, a soft launch for its 3rd party social

applications which uses OpenSocial API. A week before the

said soft launch an uproar occurs, the current platform

supports OpenSocial API 0.6 but most of the developers

wants MySpace to support OpenSocial API 0.7 which Google

releases on the same date MDP goes live to

developers. And they go as far as creating a poll to

let developers have a say whether to support v0.7 later

and continue with v0.6 or support it now.

OpenSocial v0.6 and 0.7 has viral changes.

In 0.6 there is only one package, the "opensocial.*" package.

In 0.7, the packages includes: opensocial, gadgets(core), and gadgets(feature-specific).

Days before the soft launch OpenSocial 0.7 goes Live!
Every developers are burning their candles for tomorrows event!

Keywords: myspace, opensocial, social networking

MySpace Developer Platform?

MySpace Developer Platform?

The MySpace Developer Platform is a combination of services that provides third party application developers with hooks into MySpace's data and functionality. These services include:

• A suite of online tools for creating and publishing applications (and debugging them).set of RESTful APIs (provided in json, xml, and other formats as needed) that provide endpoints for browser-to-site and site-to-site interaction. These are implemented over the http protocol using a simple, intuitive uri scheme.
• A mechanism for your application to exchange data with your own site.
• A system for end users to find and install applications on their profiles.
• Security mechanisms for protecting end users' identity, as well as communications verification between MySpace servers and your site.

OpenSocial + MySpace Developer Platform do they fit together?

OpenSocial and the MySpace Developer Platform are a series of JavaScript and server-side components that work together to provide you with a standard interface to write your apps against.

Your app is hosted in an IFrame and your code has a reference first to "opensocialreference.js", then to "MyOpenSpace.js"

MyOpenSpace.js is dependent on opensocialreference.js.

OpenSocial defines several basic social networking objects, as well as implementations for how to get and update those objects.

MyOpenSpace maps those objects to MySpace server-side API calls and it also extends the objects.

The following code is the official OpenSocial request for the friends of the "Owner" (the person who has installed the application):

function init()
{
   var dataRequest = opensocial.newDataRequest();
  
   //Create a request for the owner's friends
    var friendRequest = dataRequest.newFetchPeopleRequest(opensocial.DataRequest.Group.OWNER_FRIENDS);
   //Add the request for processing.
    dataRequest.add(friendRequest);
   //Send the request, passing in a callback.            
    dataRequest.send(response);
  
}

RAD on OpenSocial

We started with OpenSocial around mid of February. After 2weeks of learning about the API, its basic how to's and running simple samples along the way with errors and headaches. Having MySpace developers forum and irc channel really helps. Getting answers from the MySpace Dev team and 3rd party devs.

First thing first is having a sandbox access to social sites or the container which supports OpenSocial, like MySpace dev sandbox, Orkut, Ning, Hi5.

MySpace took me 3 days to have an access to their dev sandbox, while in Orkut only one day. I later found out that my application for sandbox access wasn't approved for they want more info on me, making sure that the access is given to a real developer and not just spam boots, well enough of that.

For it is a sandbox access your application can only be added to at most three users (now they changed the limit to 20 users) who are friends of your application (for security purposes) so, you can not just add millions of users or anyone on MySpace. Every application you create has a separate MySpace Accounts. So every application has a different set of friends.

MDP has its own application builder and Caja test tools (which they currently removed).
Applications can either be a pure html or js, a flash app, or an external IFrame. Since they currently don't support REST APIs you need to host your apps data. Since not all fields are in the OpenSocial API, MySpace extends those APIs.
As of now OpenSocial's Activities and Data API's are not yet supported.

Shindig Basics

What is Shindig?

As for the famous wikipedia:

Shindig refers to any sort of clever party, covered dish gathering, box social, a brawl, or it can refer to a dance party with lots of music.

Well, we are not talking of dance parties or music here and not about brawl either. Now I wonder why they named the project Shindig?

Shindig is an open source project in the Apache Software Foundation incubator which began in December, 2007, to provide an open source implementation of the OpenSocial specification and gadgets specification.

The software contains both server-side and client-side code. Once the project is mature, an installation of this product will be capable of rendering OpenSocial gadgets in a web browser.

Shindig's goal is to allow new sites to start hosting social applications under an hour's worth of work.

An hour's work? Now that is quite handy and useful guys!

Lets get going...

The architectural components of Shindig:

• Gadget Container JavaScript -- core JavaScript foundation for general gadget functionality. This JavaScript manages security, communication, UI layout, and feature extensions, such as the OpenSocial API.

• Gadget Server -- an open source version of gmodules.com, which is used to render the gadget xml into JavaScript and HTML for the container to expose via the container JavaScript.

• OpenSocial Container JavaScript -- JavaScript environment that sits on top of the Gadget Container JS and provides OpenSocial specific functionality (profiles, friends, activities).

• OpenSocial Gateway Server -- an open source implementation of the server interface to container-specific information, including the OpenSocial REST APIs, with clear extension points so others can connect it to their own backends.

The Gadget Container JavaScript provides code to generate IFRAMES pointing to gmodules.com, offers some basic gadgets functionality (e.g. dynamic height), a layout manager, the edit dialog box, a cookie-based user preferences store, and an option to point IFRAMES at your Gadget Server instance instead of gmodules.com.

The initial Gadget Server written in Java provides extensible scaffolding for processing gadgets: retrieving XML, parsing it, and processing it into a form that allows rendering of the gadget to a user or retrieval of its metadata.

The initial contribution of the Gadget Server was written in Java, Shindig is language neutral. Ning is planning to contribute an initial version of a PHP Gadget Server, and rumors of C#, Perl, and Ruby.

Downloads

Currently they do not have an automated builds infrastructure set up to offer periodic builds yet, but it will be available soon.

Building and running Shindig

The following steps provide useful information on how to build and run Shindig.

• Prequisites

• Get the code

• Build and run the code (with Maven)

• Setting up an Eclipse project

• Running with Caja

Prequisites before building Shindig

In order to build Shindig, you must have the following:

• Java (JDK/JRE) 1.5 or later installed on your system and the JAVA_HOME environment variable set.

  • See: http://java.sun.com/ for installation instructions.

• A Subversion client installed in order to checkout the code.

  • Instructions for downloading and installing Subversion can be found here: http://subversion.tigris.org/

• Apache Maven installed to perform the build.

  • Instructions for downloading and installing Maven can be found here: http://maven.apache.org/download.html

Getting the code

Create a subdirectory and checkout the Shindig code from its Subversion repository

1. mkdir ~/src/shindig (or wherever you'd like to put it)

2. cd ~/src/shindig

3. svn co http://svn.apache.org/repos/asf/incubator/shindig/trunk/ .

Building and running the code (with Maven)

To build a Web Archive (WAR) file for the Gadget server and run tests, perform the following:

1. Make sure you have the prerequisites installed first.

2. cd ~/src/shindig/java/gadgets

3. mvn package

4. Once the build successfully completes, you can install the built WAR file (gadgets.war) located in the /target subdirectory onto your JEE server.

To build the code (with no tests) and start a Jetty server that will run on at localhost:8080:

• mvn jetty:run-war

To run the Jetty server on a different port, use:

• mvn -Djetty.port= jetty:run

Once you've either installed the WAR file on your JEE server, or are running locally using the Jetty server, you can test the Gadget server using:

• http://localhost:/gadgets/ifr?url=http://www.labpixies.com/campaigns/todo/todo.xml

Setting up an Eclipse project to build Shindig

These steps, after completing the previous section, will allow you to build from within Eclipse using the Maven2 plugin. You should first install the Maven plugin, then create the new Java project.

• Create ~/.m2/settings.xml consisting solely of

• Install the Maven2 plugin

  1. Help -> Software Updates -> Find and Install

  2. Search for new features to install

  3. Create a new remote update site for the Maven 2 plugin

     • Name: Maven2 - Codehaus

     • URL: http://m2eclipse.codehaus.org/update/

  4. Select the site and click "Finish"

  5. Select only the Maven Integration plug-in (mylyn and subclipse integration have other dependencies.)

  6. Complete the installation

• Setup new workspace and project
  Creating a new workspace eliminates the performance cost from existing projects and makes it easier to manage the code.

  1. File -> Switch Workspace -> Other...

  2. Select directory to store workspace

     • Do not select a parent directory of the shindig source (e.g. ~/src/shindig) as Eclipse won't allow you to create the Java project.

     • Something like ~/eclipse/workspaces/shindig would work fine

  3. File -> New -> Java Project

     • Select 'Create project from existing source' and navigate to:
       ~/src/shindig/java/gadgets

     • Click Finish

     • If you see a dialog for "Open Associated Perspective", click Ok. Don't worry about the errors after loading as they will be fixed in the next step.

  4. Right-click the project, select Maven : Enable Dependency Management

  5. Right-click the project, select Maven : Update Source Folders

Running with Caja

Caja is an important part of OpenSocial that greatly enhances JavaScript security. Caja is managed in a separate open source project hosted by Google code projects. For more information on Caja, see: http://code.google.com/p/google-caja/wiki/CajaEasyIntro

1. Load this page: http://localhost:8080/gadgets/samplecontainer/samplecontainer.html

2. Point it to this gadget: http://hosting.gmodules.com/ig/gadgets/file/117247905274371511495/SocialHelloWorld.xml

To see the cajoled code (Firefox only), right-click inside the iframe and do "This Frame -> View Frame Source"

References

http://en.wikipedia.org

Keywords: ASF, opensocial, shindig

Want some challenge?

Want some challenge?

Google Android has something right for you...

Google has launched the Android Developer Challenge, of $10 million in awards for great and cool mobile applications built on the Android platform.

How It Works

The award money will be distributed equally between two Android Developer Challenges:

• Android Developer Challenge I: Submissions from January 2 through April 14, 2008

• Android Developer Challenge II: This part will launch after the first handsets built on the platform become available in the second half of 2008

Build Your Favorite Mobile Application

All types of applications are accepted as long as it is innovative and useful applications that make use of Android's capabilities to deliver a better mobile experience.

Suggested areas of focus:

• Social networking

• Media consumption, management, editing, or sharing, e.g., photos

• Productivity and collaboration such as email, IM, calendar, etc.

• Gaming

• News and information

• Rethinking of traditional user interfaces

• Use of mash-up functionality

• Use of location-based services

• Humanitarian benefits

• Applications in service of global economic development

• Whatever you're excited about!

Reference/s:

Google Android

On Social Networking

Different social networking sites proliferates these days, and well am one of those millions of users.

These are the social sites on my list:

Delicious a social bookmarking site.

You can access you bookmarks anywhere without your pc! You're no longer dependent in your own machine for the pages that you bookmarked with.

Twitter a micro-blogging site.

Twitter lets you update what you've been doing and letting your followers/friends know it and you will be updated of your friends too. Quite helpful if your following interesting people, you'll learn cool and interesting things in just a matter of seconds.

Another thing is tracking keywords in Twitter. Let's say your tracking google: “track google”. Just a simple entry but you IM goes ballistics! Whew! Imagine when you track google and each twitter user

around the globe who updates with the word google will be sent to you even if you're not friends. Quiet handy. You can update using IM, Phone, Web, etc. You can use Twittr, Twitteriffic, Twitbin, TwitterFox, Twhirl, and lots of tools out there!

Facebook for network of friends/social graph, joining a cause, and usually I visit it for gaming.

Lots of 3^rd party applications to play around with. Some are helpful some are nuances that requires you to invite your friends before seeing the actual application itself. Beware you're data in FaceBook will remain even if you will delete your account. Yeah, they will delete your account but your data is Archived which means its still available (for them to use maybe) but just deactivated.

YouTube

Well for videos YouTube is quite popular, though I use MySpaceTV sometimes.

Friendster

It needs further development but it's nice that they are adding 3^rd party applications now. They are now supporting Google's OpenSocial.

Old friends are friendster users, well friendster is quite popular in the Philippines.

Lets you post pictures, bulletins, and giving testimonials or comments to friends. Spread some love!

Hi5/Imeem

I usually use this sites for my music needs.

PageOnce

PageOnce is very useful if you have multiple email accounts and lots of social networking sites.

It will let you add all your accounts, so you can manage all your accounts in just one site. Great!

There are more social sites out there, connecting with your friends and learning sure brings the fun!

What Social Networking Sites are you using? Why?