Cloud Computing can be seen as the logical evolution in outsourcing IT services. The promise is that, with Cloud Computing, every company (big or small) can get IT services in a very simple way. Cloud Computing is an epitome of the change in use of IT Infrastructure and Services as the consumers will not have to spend capital of owning or renting the Hardware/Software rather they can use the resources and expense is cut down to usage only.

So, cloud computing would give extra business value over a long period of time along ensuring that the quick changing business needs can be supported better than using traditional IT services. It seems like creating a prospective horizon for changing the Information Technology world into different form than what we perceive it today.

With this change there would be certain pros and cons associated. As of now the visibility on the implications is not very distant and requires a wait and watch strategy to gradually build/change the business models for different domains.

Impact on various domains:

Having the basic idea about Cloud Computing ,in this blog we will discuss the pros and cons of cloud computing in general and would try to understand possible impact of these on the different domains.

We would see large range of highly scalable new generation agile products and services to choose from. These would provide abstraction from current process and thereby reduction in the overall cost.We also expect some standardization to come into picture.

Some of Pros are enlisted here:

Reduced Cost: Costing model is incremental i.e. pay only for what you use thus saving the money.

Increased Storage: Since resources provided by the Cloud Service Provider are virtualized and can be scaled up as required gives the consumer flexibility of unlimited storage space.

Highly Automated: Most of the things are responsibility of CSP like Software/Server update, physical maintenance of infrastructure, licensing of software/tools etc

Mobility & flexibility: Information/service is accessible from anywhere seamlessly if cloud is accessible

Currently this seems like dominance of few gig players (Amazon/Google/Oracle) and thus rise of new industry leaders and IT vendors will leave fewer options for small software companies to cope up with the evolving business model.

The other cons that we can list are:

Security: A proper security model for cloud computing is still awaited. Physical location of hardware and software being unknown would make site inspections and audits difficult. There is also risk of data loss due to improper backups or system failures in the virtualized environment.

Dependency (Loss of Control): Most of the critical things are under control of CSP (Cloud Service Provider) like – Quality of Service (QoS), Contingency Procedures, Measurement of resource utilization

Cost: Cost structure would be difficult to analyze during initial setup/migration as there could be associated hidden costs for backup, restore, disaster recovery, issue solving and compliancy regulations. Moreover future changes in the cost should also be taken into consideration.

Decreased Flexibility: Migration to different CSP would not be simple and would require proper planning starting right while developing the applications (making them generic and portable)

Taking specific businesses into account:

Telecom: Telecom sector is one of the biggest consumers of IT infrastructure, may it be software or hardware so we can expect it to be affected at all levels viz Software as a Service (SaaS), Platform as a Service (PaaS), and Infrastructure as a Service (IaaS). Cloud Computing is based on virtualization of the resources much like running multiple VMs on same hardware, we know that there would be some trade-off for this in terms of lag due to network/virtualization. The lag of fraction of second could be fine for data traffic on the network but may not be up to mark for real time voice/video based services. So it looks like some services would still require dedicated resources/hardware to meet up the SLAs.

Healthcare: Quite obviously medical businesses generate huge amount of data like patient records, biomedical research, insurance claims. It is one of the major concerns for hospitals, insurers and researchers to manage this large amount of data. Cloud computing would offer each of these players a potentially more cost-effective alternative to traditional data storage and management solutions. But still there is fear that sharing a platform in a public cloud would compromise privacy regulations, So need of a strong regulatory standard is necessary.

E-Commerce: Cloud computing would be boon to the businesses in e-commerce as they are the ones working in a pretty similar fashion since a long time viz usually these businesses run virtually on the internet only,  for this  they have to setup virtual infrastructure and services from different vendors. Interaction with various vendors will now be eliminated and limited to a single service provider who can take care of all the requirements. So we expect a substantial growth of e-commerce to be obvious in near future.

Outsourcing: Most of the current business models associated with IT infrastructure and services do include outsourcing of various activities may it be maintenance or labor. With business migrating to cloud the need for these would be decreasing in long run as most of the things would be taken care by CSP. This means that there would be a downfall expected in requirement of traditional outsourcing but on the other hand the increase in specific outsourced services for migration to cloud can be seen. Overall there should be major change/shift in the outsourced services but this would be gradual.

Currently IT costs seem to be quite competitive but still remains inflated as compared to other products and services that we use today. We do see cloud computing as a potential candidate who can play the role of game changer and help to regulate the IT economics.  But the side effects and implications are yet to be well totally foreseen and understood. Kindly share your thoughts and understanding on the above topic to have a fruitful interaction.

Jitendra Singh– Senior Software Engineer

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The last few years have seen the emergence of APIs (Application Programming Interfaces). In fact various organizations are now solely known by their APIs and have become popular among developers. Every popular site, be it Facebook, Twitter or even start-ups like Twilio are focused on exposing their core services and data via an API so that developers can take advantage of it. There are a couple of important things that is highlighted by these APIs. The first one is that they are exposed via standard mechanisms like REST and provide data typically in JSON/XML formats. The second one is that these services are primarily hosted on Cloud infrastructure. The Cloud infrastructure here is typically from the IaaS vendors (Infrastructure as a Service). Some of the key players in IaaS are Amazon and Rackspace, which provide computing resources, storage and bandwidth via a pay per use billing cycle.

Entire ecosystems of applications have developed around these services that have been exposed in the Cloud. And a large number of those applications are mobile applications. The interesting part is that the mobile application development landscape is pretty much fragmented. Each of the big OS vendors have their own language, toolsets and operating systems that make interoperable applications difficult to write. But the one place where they is a sort of a common understanding and which has resulted in a large number of client applications is that the Server layer i.e. the Cloud API exposed is pretty much the same. The REST API mechanism that is exposed over standard HTTP protocol helps create a client platform agnostic mechanism in which a developer can pick a language of his/her choice on the client side and simply code up the front –end i.e. the client application.

So a combination of an API, exposed as a Cloud Service via standard HTTP bindings is a great way to write a common server layer and power all your mobile applications via that. Doing so also addresses one of the defining principles in software engineering of reusing as much as you can instead of writing a layer for each client programming environment.

At high level you have the following architecture that can drive multiple mobile applications via a single REST layer that you expose in the cloud:

You may refer to “Extending cloud infrastructure to the mobile world” for more exposure.

To summarize:

• Build a common REST layer (API) that will expose functionality over XML/HTTP
• This common REST layer will be used by all Thick Client applications and Thin Clients. This means that even if you go the route of HTML web applications, they can use the same API.
• Further sophistication can be provided on the Server side to restrict access to certain kinds of devices. This helps in ensuring that you deliver optimum experience to the devices or even restrict access as needed.

Romin Irani– Principal Architect

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In this blog we shall first discuss about generic implementation of Single Sign-On aka SSO.Then we would take the concept forward by extending the use of SSO in a cloud environment.

Let’s start with what is SSO?

Basically SSO is a centralized access control mechanism used for multiple applications which could be independent and may or may not be interrelated. User authentication is done only once and further user requests to multiple applications are handled seamlessly.Know more about SSO here.

An appropriate analogy to help you visualize this would be iGoogle login where user once logged in can access multiple applications like Gmail/Google docs/Orkut accounts without having to login to each individual applications. Hasn’t this made our lives simpler?

Generic Implementation of SSO

There are various security mechanisms e.g. Kerberos TGT, Smart Card, One Time Password Token OTP, Integrated Windows Authentication a re few of them. We would not go in to the implementation details of these security mechanisms but in general the basic set of implementation considerations would include the following:

• SSO should know what all applications it would be catering to and accordingly it would be using the encryption/decryption keys for handling the authentication requests.
• Using different keys across applications is recommended as these keys are shared between SSO and Client applications. Securing these keys is equally important to make sure the credibility of encryption mechanism is not compromised.
• SSO would manage a central user Database which contains user roles along with the authentication parameters. These roles could be queried by the serving application to decide the user privilege/grants.

SSO Implementation in Cloud

Currently, , there are two approaches available for using SSO in Cloud:

1. Self implementation of SSO adapters based on the exposed APIs from the Cloud Service Providers, which would include writing the code to integrate with cloud applications.
2. Another approach, a simpler one would be to use Out-of-Box SSO Products available in the market or use the SSO as a service (SaaS) from Cloud itself

You can also refer this link for further related information that you may want.

Once in place, it would simplify things from the user perspective as user would have to login only once either on the machine or a web portal depending on design and then user can access various applications and resources seamlessly. By leveraging Single Sign-On capabilities an organization can merge their IT infrastructures and Cloud in a seamless manner and enable a user to access both the user’s desktops and any Cloud Services via a single password.

Some of the Benefits to mention:

• Users get convenience of single user-id/password which is easier to manage/remember.
• Saves on user time by avoiding re-entering password while switching between applications.
• Stronger security and Easier for System Admin as the management of user accounts is centralized.
• Helpful for the provisioning and de-provisioning of passwords. If a new employee joins or leaves the organization there is only one single account to activate or deactivate rather than having multiple accounts to deal with.
• In addition to preventing security issues, there are significant costs savings to this approach.
For example, Single Sign-On users are less likely to lose passwords reducing the assistance required by IT helpdesks.
• Allows anywhere, anytime seamless access.

Benefits usually come with some tradeoffs like:

• Security threat due to password leak/misuse could affect multiple applications/resources.
• SSO System should be Highly Available (HA) as failure is critical for multiple applications.

We know that SSO is not a new concept, but it is now finding new horizon for connecting organizations to Cloud service providers like Google, Amazon, Oracle. It is an evolving concept providing potential for enabling users to experience seamless access to their corporate applications along with email/social-network accounts, documents/files/photos and shared resources. Big Organizations have been using SSO systems to manage internal applications/resources since a long time but extending the SSO to cloud would be a major step ahead. Do write in your views so that we can share this important information in an interactive manner.

Jitendra Singh– Senior Software Engineer

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Desktop systems gained prominence in late 80s and they derive their name from the concept in which the entire computing unit can be placed on top of a desk. There are various uses of desktop computers dictated by the desktop users and their requirements.

• A student or business user might use the desktop for their daily activities like creating Word documents, spreadsheets, presentations or a calendar application to schedule events for the day /month / year.
• A home desktop may be used for storing multimedia files like images, mp3, videos or browsing World Wide Web.
• A person might be having some specific requirement depending on the job at hand and may use a software suite to do that. A good example would be photographer or designer using Photoshop for image editing Or a music artist using an Audio mixing setup for music recordings.

Desktop Systems:

Desktop systems are nothing but desktop computers but available on the cloud.Today internet connectivity and computers  have become quite inexpensive and are widely available while Mobile phones have moved beyond as a texting and calling to a ‘must have’ device, featuring giga bytes of Ram, giga htz of processing power and 4 ~ 7 inch displays.

With the multiple platforms available in the market, currently the convergence between different platforms is done by developing apps for each of the platforms. Let us take an example of a simple application – Dropbox.

Dropbox allows you to save your file on a remote system; it is your dedicated space on internet.  Dropbox offers a free space of 2 GB and it will automatically sync all the files that are in your Dropbox folders across all the devices that have Dropbox client installed. This is a typical example of SAAS where you dump your files on a system which gets replicated across all the devices (if they are connected and switched ON). There are many other cloud based services where not only software but platform and infrastructure also as a service.

A few more services available in the market are:

• For documents, spreadsheets etc – Docs by Google, Office 360 by Microsoft.
• Music – iCloud by Apple and Google music by Google.
• Books – Amazon Kindle, Google books and iBook by Apple.

These applications can be installed on your current desktop system, mobiles and tablets. Space of your “device at use” will be used only for caching purpose to sync timely with cloud in case the application offers offline storage model. This makes your system pretty much a client in the SAAS model.

A cloud OS or desktop in Cloud is a concept that tries to provide an integrated space for all the services from within your browser either on desktop systems or on mobile devices. These systems will offer one stop solution for your daily computing needs whether it may be word processing, games, music or running development tools. Though still immature they try to mimic the current desktop offerings via a web browser.  Let us take a look at two such products –

EyeOS – Your desktop in the cloud

EyeOS is an open source initiative; Give it a try. It requires Apache and PHP 5 and doesn’t require a database. It is nowhere near a  professional OS, but it will give you a look and feel of native desktop running in browser and it does comes preloaded with few applications like word processing tools, calendar, IM to name a few. As the name goes – right now it is just eye candy.

CloudMe

Initially called iCloud, CloudMe is another company that is developing their operating system for the cloud since 2000. And yes they have made a pretty cool interface, it is best among the competitors. It is a clean, carefree, zero-configuration XML-based OS, running within browser.  They offer a suite of 40+ applications that you can install on your desktop in the cloud. It offers tools for SAAS application development that will run on their internet-OS.  Currently the registration is free and it also offers 3 GB of free space. You can try it here.

There are three other major players which have recently done great cloud services and it would be worth taking a look at these.

Google cloud solutions – Applications from Google require an active data connection and are pretty fast. Google is targeting the future where internet will be available in every corner of the earth and they all run from within any browser. The data is stored in Google servers. Although the model is great and holds a lot of promise, in current scenario for people who are already connected with internet 24×7, its full potential however will be realized only in near future with unlimited and uninterrupted connectivity being a reality.

Apple iCloud – Apple has recently launched iCloud, it offers seamless data syncing between all the Apple devices. Data sync capabilities are built into the applications. Apple solution is good for current scenario where people do get disconnected with internet and have to rely on offline storage model for completing the task at hand, be it making a spreadsheet or listening to music.

Microsoft LiveMesh – This is a product from Microsoft using which you can create a mesh of all the systems owned by you and having a browser running on any system to perform task on any system. It is like a refined version of Remote desktop. To add to this Microsoft also offers 5 GB of free storage – Windows Live Skydrive in the Mesh, that can be synced with all or a selective set of devices.

To Conclude

Desktop as a cloud is still immature, but yes it holds a lot of promise. To gain user acceptance, it has to provide the rich experience of desktop system and a facility to install majority of application or application clones that are currently used by a desktop consumer.

Pradeep Sharma– Technical Lead – Mobile CoE

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Cloud Computing now finds a way through most technical discussions. Irrespective of the medium (Web Search, Twitter, Online Journals), you will find Cloud Computing being discussed. But ask anyone the definition of Cloud Computing and you will be hard pressed to get two exact definitions from different people.

Some define it as servers available for rent to storage or applications that we access from the browser, etc. All of them are right in ways. But is there a definition that describes the essence of Cloud Computing. While there might be various definitions of that, we shall look at one of the definitions of Cloud Computing in this blog post. It is known as the 5-3-4 Formula.

The 5-3-4 Formula is further broken down into the following:

5 key characteristics

The key characteristics are:

• On Demand Self Service: As the application owner, you should be able to provision additional computational resources for your application, look up reports and perform Administration tasks without requiring human intervention. Cloud vendors are now providing monitoring and provisioning tools where the user is in full control of provisioning things.
• Ubiquitous Network Access: We are living in a world where a desktop and laptop computer is not the only way that people access the Internet. Mobile device access is increasingly becoming a major source of traffic to your application. And it is not just mobile devices but devices fitted in vehicles and even our Televisions that are accessing the Internet. These explosion of device types and various networks around the world brings to the important concept of “ubiquity”. It means that no matter from what device or network , one should be able to reach your application via the public cloud networks. And this access is the cornerstone of cloud computing. Always available and from anywhere.
• Location Independent Resource Pooling: This feature is key to providing your additional resources. As a consumer one should not be worried about how the cloud allocates additional servers, takes care of multi-tenancy and allocation of physical and virtual servers in different geographical locations to meet your demand. Location Independent Resource Pooling is the ability of the Cloud to do exactly that.
• Elasticity: If you have released any online web application you can now look back and see those days where the number of hits to your sites peaked due to a new release or a press announcement. There will be spikes in user activity and you cannot scramble around for additional hardware when that happens. Cloud Computing addresses this through Elasticity. What it means is that the Cloud Vendors will automatically allocate you more resources as your application needs it. Extra Servers, more memory, more storage, etc will be available to your application if the need arises.
• Pay per Use: This is one of the key characteristics and one of the reasons for cloud computing gaining acceptance. Just like you can seldom predict your peak usage, it is important that you pay only for the amount of resources that you use. Cloud Computing vendors have various schemes starting with freemiums and then tiered pricing that clearly specify the quotas that are available based on what they charge you. At any point in time, you can switch between plans and allow for extra charging depending on additional resources that your application might use.

3 delivery models

Cloud Computing is typically delivered in 3 models and each one builds on the other

• IaaS : Infrastructure as a Service. This layer is about providing processing power (CPU cycles), storage, bandwidth, networks and other infrastructural resources. Some of the key players over here are Amazon Web Services (AWS) , Rackspace and others.
• PaaS: Platform as a Service. This layer builds on top of the IaaS layer and provides a developer with a complete stack on which to build applications. The stack comprises APIs that abstract out the low level details and allow the developer to quickly use them to build out the application. The key players in this space are Google (Google App Engine), Microsoft (Azure), Sales Force (force.com) and recent entrants like CloudFoundry from VmWare.
• SaaS: Software as a Service. In simple terms, these are ready made applications that you can use either for free or a fee. You simply need to sign up, optionally pay and login to use the software. Examples of this include SalesForce (CRM), Gmail, Google Apps, etc.

4 deployment models

The 4 deployment models available are given below:

• Public
• Private
• Hybrid
• Community

Typically, the public cloud is what is best known to most of us. While classification does exist for other types like private, hybrid (mix of public/private) and community – they are not that prevalent and no clear classification exists. So for all practical purposes, when we refer to the cloud, it is public and with appropriate authentication and access control mechanisms built in.

So the next time, someone asks you to define “Cloud Computing”, you can simply say “5-3-4”.

Romin Irani– Principal Architect

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In this blog post, I am going to talk about the very basic steps that are mandatory to get application published in to Android Market. Android Market https://market.android.com is a store developed by Google for Android devices, it allows users to download published apps of different developers.

Follow the below procedure to generate a suitable .apk file for Android market.

1. Specify Version

To define the version information for application, set following attributes in the application’s manifest file:

android:versionCode - An integer value that represents the version of the application code

android:versionName – A string value that represents the release version of the application code

Versioning is required for following reasons:

1. To check compatibility and dependency issues between applications.
2. While Publishing and Upgrading the application to Android market
3. It is also used in the Android Market to automatically offer application upgrades to users.

Here’s an example manifest file that shows the android:versionCode and android:versionName attributes in the <manifest> element.

<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
package="com.example.package.name"
android:versionCode="2"
android:versionName="1.1">
<application android:icon="@drawable/icon" android:label="@string/app_name">
...
</application>
</manifest>

2. Signing of Application

Google expects a Signed copy of the application in order to verify the developer account. The Android system will not install or run an application that is not signed. In preparation of signing the application, you must first ensure that you have a suitable private key, if you don’t have any private key then generate it with following 2 methods.

A. Using Command line tools

B. Using Eclipse ADT

A. Using Command line tools

Following are the 4 processes to generate published .apk file.

a. Obtain a suitable private key

Use following command to generate a private key:

$ keytool -genkey -v -keystore my-release-key.keystore -alias alias_name -keyalg RSA -keysize 2048 -validity 10000

Command line attributes:

• -v = Verbose mode
• my-release-key.keystore = generated key file
• alias_name = alias name for application
• validity = expiry time here is 10000

The above command generates the keystore as a file called my-release-key.keystore. The keystore and key are protected by the passwords you entered. The keystore is valid for 10000 days.

b. Compile the application in release mode

To export an unsigned .apk from Eclipse follows th steps:

1. Right-click the project in the Package Explorer
2. Select Android Tools > Export Unsigned Application Package.
3. Then specify the file location for the unsigned .apk.

c. Sign your application with your private key

When application package is ready to be signed, then you can sign it by using the Jarsigner tool.

$ jarsigner -verbose -keystore my-release-key.keystore my_application.apk alias_name

Command line attributes:

• -verbose = Verbose mode
• my-release-key.keystore = generated key file.
• alias_name = alias name for application
• my_application.apk = unsigned application

While running the above command, Jarsigner prompts you to provide passwords for the keystore and key. It then signed the .apk file. Use following command to verify that your .apk is signed:

$ jarsigner -verify my_signed.apk

If the .apk is signed properly, Jarsigner prints “jar verified”.

d. Align the final APK package

Once you have signed the .apk with your private key, run zipalign on the file.The zipalign tool is available inside the Android SDK, tools/ directory folder. Follow the command to align your .apk file:

$ zipalign -v 4 your_project_name-unaligned.apk your_project_name.apk

The input .apk must be signed with your private key before you optimize the package with zipalign

B. Using Eclipse ADT

Follow the steps to create a signed and aligned .apk by Eclipse ADT:

1. Select the project in the Package and select File > Export.
2. Open the Android folder, select Export Android Application, and click Next.
3. The wizard now guide you the process of signing your application, including steps for selecting the private key or creating a new keystore and private key.
4. Complete the Export Wizard and your application will be compiled, signed, aligned, and ready for distribution.

3. Preparing to Publish: A Checklist

Following checklist is useful while publishing android application to market.

1. Complete your application testing extensively on an actual device
2. Consider adding licensing support
3. Specify an icon and label in the application’s manifest, you define the attributes android:icon and android:label in the <application> element of the manifest.
4. Turn off logging and debugging and clean up data/files
5. Remove the android:debuggable=”true” attribute from the <application> element of the manifest.
6. Specifying an appropriate value for both the android:versionCode and android:versionName attributes of the <manifest> element in the application’s manifest file.
7. Generate a private key by keytool utility and compile it with application by using release mode.
8. In <manifest> file check that the proper permissions are used, so that user can grant permissions when application is installed in device.

For example:

<pre>&lt;uses-permission android:name="android.permission.CAMERA"&gt;&lt;/uses-permission&gt;
&lt;uses-permission android:name="android.permission.READ_PHONE_STATE"&gt;&lt;/uses-permission&gt;
&lt;uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE"&gt;&lt;/uses-permission&gt;
&lt;uses-permission android:name="android.permission.INTERNET"&gt;&lt;/uses-permission&gt;</pre>

9. For supporting maximum screen sizes of devices used by customers, following attribute must be added in the Manifest file.

With these steps and procedures you are quite set to upload and disclose your Android application to the world .Some attractive screenshots along with a perfect description should get you going. So keep developing your applications with interesting UI and continue adding more innovative apps to the market and your portfolio. And if you encounter issues do write us back here and we shall surely reply.

Suresh Rapakala– Sr. Member at Xoriant QA Center of Excellence

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What are Widgets?

Well, basically they are simple miniature applications/app views that can be embedded in other applications for e.g. Home screen.. I am quite sure you must be hooked up to Facebook, so say you could have a miniature view on the home screen, that allows you to post on to your wall and then constantly update you with recent likes or comments and status updates in a small scrollable view. Well this is not just a possible concept, it exists. This is exactly what a widget is. Likewise widgets exist for a variety of applications like stock market, audio manager, battery manager etc. Everything is on the home screen and you don’t even have to launch the application. The best part about a widget is, it can update itself constantly if required without you having to refresh your screen. That’s precisely as easy as it gets!!!

Now have a look at the demo snaps and then let’s get on with creating these widgets. It’s really very simple. What we are going to do is create a simple digital clock. So let’s begin!!!

Now follow these steps and you will be on your way to creating your very own widgets for the Android Application.

Step 1: Modify Android Manifest File For the Application:

What we are essentially doing here is specifying the broadcast receiver that will process the app widget updates. The meta-data tag is used to inform android about the widget provider. In this case it is located in res/xml/widget.xml. The activity tag is used to declare the activity and the event that launches it.

Have a look at the code snippet below:

<application android:icon="@drawable/icon"
                 android:label="@string/app_name"
                 android:theme="@android:style/Theme.Translucent">

		<receiver android:name=".Widget" android:label="Custom Digital Clock">
            <intent-filter>
                <action android:name="android.appwidget.action.APPWIDGET_UPDATE" />
            </intent-filter>
            <meta-data android:name="android.appwidget.provider" android:resource="@xml/widget" />
        </receiver>

        <activity android:name=".info">
        	<intent-filter>
                <action android:name="android.intent.action.MAIN" />
                <category android:name="android.intent.category.INFO" />
            </intent-filter>
        </activity>

    </application>

Step 2: Create Widget Provider xml file as specified in the manifest:

Following  is the definition of the widget. It has only one element i.e. appwidget-provider which takes attributes specifying minimum width, height, the update frequency and the initial layout or design for the widget. Now that was simple wasn’t it!!!

<appwidget-provider xmlns:android="http://schemas.android.com/apk/res/android"
android:minWidth="294dip"
android:minHeight="72dip"
android:updatePeriodMillis="0"
android:initialLayout="@layout/widget"/>

Step 3: Create Layout for the Widget(widget.xml)

Now this step is pretty self explanatory. You simply have to create layout to represent the widget. Yet the Code sample is available as always for your reference.

<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout android:id="@+id/Widget"
 	android:layout_width="wrap_content"
	 android:layout_height="wrap_content"
 	xmlns:android="http://schemas.android.com/apk/res/android">

 <TextView android:textColor="@android:color/primary_text_dark"
	android:padding="10dip"
	android:textSize="35dip"
	android:layout_width="wrap_content"
	android:text="12.30.35 PM"
	android:layout_gravity="center_horizontal"
	android:typeface="monospace"
	android:textStyle="bold"
	android:layout_marginRight="3dip"
	android:background="@null"
	android:layout_marginBottom="3dip"
	android:layout_marginLeft="3dip"
	android:id="@+id/widget_textview"
	android:layout_height="wrap_content"
	android:layout_marginTop="3dip"/>

</RelativeLayout>

Step 4: Create Widget Provider Class

Don’t get alarmed by the name here, it’s very simple. All you need to do is create a class that extends the AppWidgetProvider class. This is the same provider specified in the manifest file as the receiver.

The onUpdate() method needs to be overridden to include the necessary code to update time, which can be easily done using the TimerTask class in the java.util package and then it can be represented in a text view as per layout.

The onUpdate() method is called whenever an update is to be performed. Additionally pending Intents may be used to configure action to be performed on click of the widget. In this case the widget will display a simple information activity on click. Pending Intents can be given to other applications which serve as permission for the app to perform specified operation.

public class Widget extends AppWidgetProvider
{
    private Handler mHandler  = new Handler();
    RemoteViews views;
	AppWidgetManager appWidgetManager;
	ComponentName currentWidget;
	Context context;
	DateFormat format = SimpleDateFormat.getTimeInstance(SimpleDateFormat.SHORT,Locale.getDefault());

	public void onUpdate(Context context, AppWidgetManager appWidgetManager, int[] appWidgetIds)
	{

		//Update Widget Using a a runnable and a handler to manage it.
		.
		// some code here.
		.
		mHandler.removeCallbacks(mUpdateTask);
       		mHandler.postDelayed(mUpdateTask, 100);

	} 

	final Runnable mUpdateTask = new Runnable()
	{
	   public void run()
	   {
		   Intent informationIntent = new Intent(context,info.class);
	       PendingIntent infoPendingIntent = PendingIntent.getActivity(context, 0, informationIntent, 0);
	       views.setOnClickPendingIntent(R.id.Widget, infoPendingIntent);
		   views.setTextViewText(R.id.widget_textview,format.format(new Date()));
		   appWidgetManager.updateAppWidget(currentWidget, views);
		   mHandler.postDelayed(mUpdateTask, 1000);

	   }
	};

Step 5: Create Information activity and xml file

This is a simple activity with a text view that is used to display some information on click of the widget. Creating a layout may be a piece of cake for you by now but the sample is there for your reference as always.

<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
			    android:layout_width="fill_parent"
			    android:layout_height="fill_parent"
			    android:background ="@android:color/white"
			    android:scrollbars="vertical">

	<TextView android:layout_width="fill_parent"
			  android:layout_margin="3dip"
			  android:textColor="@android:color/black"
			  android:layout_height="wrap_content"
			  android:text="@string/information" />

</RelativeLayout>

So here we go, with the help of a few simple steps, we have created our very own widget. Wasn’t that straightforward? I am sure you would be amused at the simplicity of the thing and yet its elegant beauty which is there for all to see.

As with everything, along with a dozen of advantages there are a few downsides to it , else how would we improvise? So a few things that you must keep in mind while you are involved in creating widgets are:

• They can consume a lot of resources, battery life so you need to regularly kill open unused apps.
• They take some real estate on screen, so you need alternate screens and launchers for some extra space.

So keep these in mind while making and embedding widgets on your home screen and you should have absolutely no problem. If you still get stuck while making your widget you can always use the entire source which is available for download or leave a comment and I would be pleased to answer it.

Vinay Ramkrishnan– Team Member – Mobile CoE

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Many of us have come across some sort of a disarray in retrieving the nth maximum record in a given database. Most of the PL-SQL developers and DBAs are in continuous efforts to execute enormous queries in order to get the desired output. I have myself encountered several critical issues during PL-SQL programming on the projects which I work. But out of those, I am keen on sharing one such case in point which shows ever pertinent issue of finding out the nth maximum record in a database.

Nth maximum record:— It means retrieving the second or third or tenth maximum record for a given database.In my case, I had to retrieve nth maximum salary from a particular persons table i.e. employees of a company.
There may be several ways to retrieve the above output. But a few developers include ‘rownum’.   in their queries which  is probably not going to give the correct result.

Lets us see for instance,

A query normally written by most-
select * from (select persons.*, rownum as r1 from persons order by salary desc) where r1=2
The result of the above query is totally based on the way of records inserted into the table.
e.g. — The structure of the table persons is
CREATE TABLE PERSONS
(
P_ID INTEGER NOT NULL,
LASTNAME VARCHAR2 (255 BYTE) NOT NULL,
FIRSTNAME VARCHAR2 (255 BYTE) NOT NULL,
ADDRESS VARCHAR2 (255 BYTE),
CITY VARCHAR2 (255 BYTE),
SALARY NUMBER
)

Following are the insertion statements for the persons table:

- INSERT INTO PERSONS ( P_ID, LASTNAME, FIRSTNAME, ADDRESS, CITY, SALARY ) VALUES ( 3, ‘first’, ‘ankush5′, ‘city1′,   NULL, 500);

-INSERT INTO PERSONS ( P_ID, LASTNAME, FIRSTNAME, ADDRESS, CITY, SALARY ) VALUES ( 1, ‘second’, ‘ankush8′, ‘city2′, NULL, 80);

-INSERT INTO PERSONS ( P_ID, LASTNAME, FIRSTNAME, ADDRESS, CITY, SALARY ) VALUES ( 4, ‘third’, ‘ankush’, ‘city3′, NULL, 90);

-INSERT INTO PERSONS ( P_ID, LASTNAME, FIRSTNAME, ADDRESS, CITY, SALARY ) VALUES ( 2, ‘fourth’, ‘eankus’, ‘city4′, NULL, 600);
COMMIT;

If you keenly observe the above statements, there is no order of inserting the value of salary in persons table. In short the inserting values of salary are in random manner i.e not sorted. The person with salary of 500 comes first and 80 second and 600 in last as per the input in the database.

And, if a developer is to execute the query which includes rownum to retrieve the maximum second salary,
select * from (select persons.*, rownum as r1 from persons order by salary desc) where r1=2 order by salary desc.
Then, the output would be 80 because rownum for that row is 2. And the reason for the rownum =2 for this record just because it was inserted in 2nd place. So the logic of using rownum for retrieving the maximum 2nd salary is quite unjustifiable.

After many permutations and combinations, I finally arrived at what according to me is an accurate way of writing the query.That would be using dense_rank.

A query written using dense _rank:

SELECT * FROM (SELECT persons.*, DENSE_RANK() OVER (ORDER BY salary desc) s_dense_rank FROM persons ) WHERE s_dense_rank = 2

If I execute this query to retrieve the maximum second salary, I am most certain to get my desired output i.e. 500 even though it was inserted first in the table.

In Oracle/PL-SQL, the dense_rank function returns the rank of a row in a group of rows. The dense_rank function can be used two ways – as an Aggregate function or as an Analytic function. In my problem, I have used dense_rank as an Analytic function.

This is one of the ways I could arrive at. Please leave your comments and if you have any such similar situation and related solutions, please share them across to have a fruitful interaction.

Sachin Padha– Software Developer ( PL-SQL Developer )

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In this post we shall discuss about the Quick Action design pattern in more detail with which you will be  have a clear understanding of the significant parts of a typical user friendly interface.

Introduction:

As previously mentioned, Quick Actions are basically actions/functions in a popup bar that are triggered by specific visual elements/buttons/items on the screen. Quick Actions are used to display contextual actions typically used in list views but not limited to it. You can imagine a phone-book or contact list on the phone. Now, there are certain set of actions that will be common to all contacts in the views like; make a call, send message, edit contact or may be even transfer files by  Email, Bluetooth etc. Basically these functions that are common to items in a context can be put in the Quick Action bar. This way the screen is uncluttered and simple and more importantly we needn’t sacrifice on the actions needed.

After having learnt about  detailed source code for an Action bar, next let us begin with the creation of the Quick Actions bar. We will make this short and simple, so just follow on…

To begin with, the demo snaps look like this:

Step 1. Create Actionable Items

The below code snippet is used to create an actionable item i.e. the actions you would want to place in the quick action bar. Creating an actionable item involves specifying the title, setting an icon that represents the item which will help you relate to the action, and finally set a Listener for the action. The term itself is self-explanatory. Yes, it is used to determine the action to be performed when clicked or pressed. As far as the icon /image goes, it can be easily set by referring to it from the resources as is the case with any external resource set in android which you would aware of, I am most certain.

final QuickActionIcons edit = new QuickActionIcons();;

 edit.setTitle("Edit");
 edit.setIcon(getResources().getDrawable(R.drawable.edit));
 edit.setOnClickListener(new OnClickListener()
 {
 public void onClick(View v)
 {
 Toast.makeText(QuickActionSampleAppActivity.this,"Edit Contact",Toast.LENGTH_SHORT).show();
 }

 });]

The above actions can be repeated depending upon the number of actions to be put in.

With this, you have successfully created your actions. Next we shall create the quick action dialog that should be displayed on clicking some button or tab.

Step 2: Create Quick Action Dialog

This part is even simpler. Like in this example, when an item in the list view is clicked / pressed, a new quick action bar/dialog is created. Then all the actionable items that you have created in the previous step are appended one by one to the quick action bar. After this you simply have to specify the animation style i.e. how do you want the dialog to be displayed on screen.

resultPane.setOnItemClickListener(new OnItemClickListener()
    {
		public void onItemClick(AdapterView<?> parent, View view, int position, long id)
		{
			QuickActionBar qab = new QuickActionBar(view);

			qab.addItem(edit);
			qab.addItem(call);
			qab.addItem(send_data);
			qab.setAnimationStyle(QuickActionBar.GROW_FROM_LEFT);

			qab.show();
		}
    });

And then finally you display the created quick action bar.

Step 3: Create Animation Files

All animations that you specify will have to be supported by corresponding XML files that allow the animation to play out. These XML files will form a part of your resources. It‘s really not that difficult to create these animation files. Have a look at a sample below.

<strong></strong>

<set xmlns:android="http://schemas.android.com/apk/res/android">
 <scale
 android:fromXScale="0.3" android:toXScale="1.0"
 android:fromYScale="0.3" android:toYScale="1.0"
 android:pivotX="50%" android:pivotY="100%"
 android:duration="@android:integer/config_shortAnimTime"
 />
 <alpha
 android:interpolator="@android:anim/decelerate_interpolator"
 android:fromAlpha="0.0" android:toAlpha="1.0"
 android:duration="@android:integer/config_shortAnimTime"
 />
</set>

Step 4: Create Layouts for actionable Items and Quick Action Bar

Some additional things that you would have to do are create layouts for the quick action dialog and the actionable items. It’s as simple as the layouts that you are so used to creating in android day in and day out. Go on and have a look at the snippet for the quick action items any way.

<LinearLayout
 xmlns:android="http://schemas.android.com/apk/res/android"
 android:orientation="vertical"
 android:layout_width="fill_parent"
 android:layout_height="wrap_content"
 android:gravity="center_vertical|center_horizontal"
 android:paddingTop="0dip"
 android:paddingBottom="0dip"
 android:paddingLeft="20dip"
 android:paddingRight="20dip"
 android:clickable="true"
 android:background="@drawable/button_state">

 <ImageView
 android:id="@+id/image"
 android:layout_width="fill_parent"
 android:layout_height="wrap_content"/>

 <TextView
 android:id="@+id/caption"
 android:layout_width="fill_parent"
 android:layout_height="fill_parent"
 android:gravity="center_vertical"
 android:textSize="12sp"
 android:textColor="#ff000000"/>

</LinearLayout>

You may try out the quick action dialog layout by yourself. If you’re stuck you can refer to the complete source code on Quick Action that is available anyway.

By following these 4 simple steps , you are all set and ready to have quick action dialogs zooming around in your app. So go on and try them out.

With a few design guidelines on User Friendly Interface for Android followed by:

• Android UI Design Pattern-Dashboard
• Android UI Design Pattern-Action Bar
• Android UI Design Pattern-Quick Action Bar;

I am most certain that you can now design and develop an efficient interface. Should you have any questions on any topic, I would be pleased to answer them.

Pradeep Sharma– Technical Lead – Mobile CoE

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Mobile device markets that includes Smartphones, Tablets, PDAs etc. is growing dynamically making the mobile application developers strive to deliver most robust, scalable applications with quality assurance Every device platform creates a unique testing environment challenging the mobile application developers to follow different testing strategies. Here we shall see how different types of testing approaches can be taken up for a variety of mobile platforms.

Numerous different mobile platforms available for mobile applications to name a few:

• Apple’s iOS
• Google’s Android
• Nokia’s Symbian, Maemo and MeeGo
• Palm/HP’s WebOS
• Samsung’s Bada
• RIM’s BlackBerry OS., and many more.

As mentioned, every platform needs a different testing approach. A combination of manual and automation testing can be done for an effective outcome.

Following are different types of manual testing for mobile environment:

• Functionality Testing:

Functional testing mainly includes finding device specific bugs and navigational issues of application. This type of testing should be done at the initial stage when the application is under development. In functional testing we can check database or network queries with response times, crashes and memory issues. Functionality testing of a mobile application is a black-box type of testing to assure that the application is functioning as per the business specifications.

• Usability Testing:

Usability testing encompasses mobile interface testing, application navigation testing, and intuitiveness of the application, consistency, and soberness of color scheme. An ISO standard defines usability as “the extent to which a product can be used by specified users to achieve specified goals with effectiveness, efficiency and satisfaction in a specified context of use”.

In Usability testing ease and efficiency of the user and content verification will be tested as defined in common Usability guidelines.

• Network Connection Testing:

Every mobile application which utilizes internet needs to be tested under different networks. These are a few networks for testing applications:

2G (GPRS, CDMA, EDGE), 3G and WiFi.

This is a necessity because most of the times the server responses are different for different type of networks. This testing helps us check application behavior under different networks.

• Installation Testing:
  

While installing, the application should install required softwares automatically on the device. And while uninstalling the application, it should remove all the available content and databases from the device which are used by application.

• Performance Testing:

Performance testing is required for finding memory related issues in application when data is excessive, due to devices having less memory as compared to simulator, this testing is required to be done on device only. By this testing approach, we can find the stability and performance of application under excessive data.

• Stress Testing:

This testing is required for getting the application response time while clicking on different buttons regressively and adding more data on device. We can get different crashes and hangings of application while running the application for long time.

In absence of mobile devices, simulators have always played a vital role for testing mobile device applications, although device testing is always the ideal way as it represents more likely end user scenarios, the significance of simulators in testing cannot be ignored. To have an effective testing with the help of a simulator, it’s necessary to explore all the capabilities of simulator.

Simulator versus device testing:

Simulators are mainly used for functional testing of basic flows. Simulators are not used for performance and usability testing, but the final testing is conducted on actual devices so crashes and hangings can be identified. One cannot get quality application while relying only on simulator. Device testing is necessary for all the applications, as with device testing we can understand the application behavior on different networks.

Simulator:

Is a software application that can accurately imitate a mobile phone. Simulator is mainly used by developers to check the functionalities implemented under development phase.

Let’s discuss the pros and cons of using simulators:

• Pros:

- Helps in isolating issues which are not volatile network connection dependent
- Provides a wide variety of testing over different types of device simulators for the same build
- Allows to test the same build in multiple device screens.

• Cons:

- Simulators of older generation handsets don’t resemble the device as closely
- Some issues which are hit by the speed at which input was given cannot be reproduced easily
- Hardware/Firmware environment variations detectable in device testing only
- Device testing is always preferred as it represents more likely end user scenarios.

Device: Is the actual handset where application installed and runs.

There are some pros and cons while using real devices for testing as well.

• Pros:

- Finds actual issues of application.
- Finds crashes, memory leak issues which can not found on simulators.
- Checks application over 2G and 3G and different networks
- Checks application behavior while incoming call, SMS, MMS and alarm.

• Cons:

- Expensive for compatibility testing of application over wide range of devices
- Consumes more time for adding excessive test data for testing purpose.

Checklist to follow while testing a mobile application:

Following is a basic checklist which is required while testing mobile application for any platform:

1. Installation & Uninstallation: To verify whether the application can be installed & uninstalled successfully.

2. Network Connectivity:

• The application can use simultaneous connections properly
• The application follows the GSM Offline profile correctly when making connections.
• When GSM Offline profile is selected, application cannot take network connection or send an SMS/MMS
• The application can utilize WLAN, 2G and 3G networks correctly.
• Performance of application during network connectivity problem.

3. Call/SMS/alarm handling: Verify that Application pauses and resumes for the same state when there is an incoming phone call/SMS/MMS/Alarm notification.

4. Check the look & feel of the application

5. Content: Check if enough information is displayed

6. The application must function as defined in the Help, user’s guide, or functional specification

7. Performance : Application and inner pages load time.

Automation Testing:

Automation testing is usually extended to perform tasks impossible with manual testing in large applications. An automated software testing tool is capable of playing pre-recorded and predefined actions. The results are mapped to the expected behavior and report the success or failure of these manual tests. Once automated tests are created they can easily be repeated. Having experienced the efficiency of automated software testing, it has become an important part of an application testing.

Automation tools available for testing:

Mainly mobile testing is done manually on actual devices. Some of the following tools are available in to test the functionality as well as usability of application.

1. Robotium for Android
2. Testquest, try, and digia for Symbian
3. FoneMonkey for IPhones
4. Memory sweep for IPhone
5. Other tools: eggplant, VNC Robot, Hopper and TestQuest.

Advantages and Limitations of Automation Tools:

Advantages:
- Multiple tests can run in less time with fewer resources
- Automated Tools run tests faster than human users
- Can reuse tests on different versions of an application.

Limitations:
- Unable to test all the functionalities and Usability of application through automation tools
- Proficiency is required to write the automation test scripts for application different functionalities
- Debugging the test script if any error is present in the automation test script
- Storing and maintenance of test data is difficult.

I believe that this comprehensive information will be quite helpful to you if you are looking at some methods for an effective approach to test a mobile device application. You can leave your comments and/or questions; I would be looking forward to having an interactive conversation.

Suresh Rapakala– Sr. Member at Xoriant QA Center of Excellence

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