WIDGETS

DASHBOARD:              
Dashboard is an application for Apple's Mac OS X operating systems, used for hosting mini-applications known as widgets. First introduced in Tiger, it is a semi-transparent layer that is invisible to the user unless activated by clicking its icon in the Dock. Alternatively, the user can invoke Dashboard by moving the cursor into a preassigned hot corner, by pressing a hot key, or mouse button, any of which can be set to the user's preference.
When Dashboard is activated, the user's desktop is dimmed and widgets appear in the foreground. Like application windows, they can be moved around, rearranged, deleted, and recreated (so that more than one of the same Widget is open at the same time, possibly with different settings). New widgets can be opened, via an icon bar on the bottom of the layer, by dragging a widget icon out into the layer. After loading, the widget is ready for use.
Despite being a standard and non-removable part of all subsequent OS versions, actual usage of Dashboard is widely thought to be low and development of new widgets has slowed substantially since the application was first introduced.

Contents 1 Creation of widgets 2 Widget functions and capabilities 3 Graphics 4 Comparison with Konfabulator 5 Included widgets 6 Widgets on the desktop 7 Widgets on the iPhone OS 8 See also 9 References 10 External links

 Creation of widgets

Dashboard widgets are created using Hypertext Markup Language (HTML), Cascading Style Sheets (CSS) and JavaScript. Because the same languages are used for creating websites, many web developers can already build them. Widgets themselves are, at the core, simply HTML files that are displayed within the Dashboard layer; they use the WebKit application framework that is also used in Apple's Safari web browser, meaning even users running earlier versions of Mac OS X — where Dashboard is unavailable — can build them.
When a Dashboard widget is built, it usually consists of six files:

• The widget's HTML file, which is the actual file that will be displayed in the Dashboard layer
• The widget's CSS file, which is used for styling the widget (but is called on from the HTML file)
• The widget's JavaScript file, although it may be implemented directly within the HTML file if the developer desires
• The widget's Property List (called “Info.plist”), which is what Dashboard uses to load the widget’s properties (i.e.: name, version, HTML file, etc.)
• The background image of the widget, in PNG format
• The icon that is displayed in the menu bar

Once all of these files are in the root of a directory, it is given a name and the extension ".wdgt", and then it can be opened up in Dashboard as a widget. More complex widgets may also include a Cocoa widget plugin (for platform-specific functionality), one or more JavaScript files (for text scrolling, preferences, etc.) or multiple images (for personalized select menus or buttons).
Mac OS X v10.5 "Leopard" includes an application called Dashcode, which is a more user-friendly way of creating widgets. Another new feature of Mac OS X Leopard is called "Web Clips" which lets users easily create widgets from parts of a webpage. During the WWDC 2007 keynote, Steve Jobs made widgets out of the following: the featured news headlines on Yahoo.com, the top ten most searched terms on Google, the Photo of the Day on National Geographic, the Dilbert comic strip, and the box office information from Rotten Tomatoes. The user can also customize the border to further personalize the widgets.

 Widget functions and capabilities

Dashboard widgets, like web pages, are capable of many different things, often to perform tasks that would be tedious or complicated for the user to access manually. One example is the Google Search widget, which simply opens up the user's browser and performs a Google search. Other widgets, like Wikipedia, grab the contents of web pages and display them within Dashboard. Some widgets can also serve as games, using Adobe Flash (or another multimedia authoring program) to create games just as if they were in a browser. It is also possible for Mac users to create their own widgets using built-in software.

 Graphics

Dashboard uses a variety of graphical effects for displaying, opening, and using widgets. For instance, a 3-D flip effect is used to simulate the widget flipping around, by clicking on a small i icon in the right bottom corner, the user can change the preferences on the reverse side; other effects include crossfading and scaling from icon to body (when opening widgets),a "spin cycle effect" when a widget is focused and the user presses Command-R or a suck-in effect when they are closed. On sufficiently powered Macs, widgets will produce a ripple effect when they are opened, like a leaf falling onto water. These effects can be taxing and superfluous, consuming CPU resources^{[clarification needed]}, but with the help of OS X’s Quartz Extreme and Core Image graphics architectures, sufficient computing power to render them in real time is available. As with Exposé, Front Row and the minimise effect, holding shift down while calling the Dashboard or opening the Dashboard menu bar will display the effect in slow motion.

 Comparison with Konfabulator

Many people have made comparisons between Konfabulator and Apple's Dashboard, especially after Apple announced the feature while Mac OS X v10.4 was in development. It was a subject of debate in the online community following the few months before Mac OS X Tiger's official release.
One school of thought came to the conclusion that Dashboard was a "rip-off" of Konfabulator. It points out the visual and functional similarities between Dashboard has been widely compared to Konfabulator (now Yahoo! Widget Engine) and sometimes called a copy of it, due to the similarities between their graphical aspects and the fact that they both use the term “widgets” to describe the objects in their environments.^[1] Konfabulator may in turn have been based on Apple’s Desk Accessories, first released in 1984 with the original Macintosh. Desk Accessories, similar to widgets, were small mini-applications that operated on a user’s desktop. After the introduction of System 7 and cooperative multitasking the necessity of creating Desk Accessories was removed and developers were encouraged to create applications instead. The OS continued to support them, for backward compatibility, until the switch to Mac OS X (In fact, the Calculator desk accessory remained in the Mac OS through version 9, 17 years without a significant update).^[2][3]
The code bases for Konfabulator and Dashboard are also different: Konfabulator uses XML and JavaScript to generate Widgets, whereas Dashboard uses HTML, CSS, JavaScript, and Objective C.^[4]

 Included widgets

In the first version of DashBoard released with Mac OS X v10.4 - v10.4.3, Apple included 14 widgets with it. They consisted of:

• Address Book (application)
• Business
• Calculator
• Calendar
• Dictionary
• Flight Tracker
• iTunes Controller
• Phone Book
• Stickies
• Stocks
• Tile Game
• Translation
• Unit Converter
• Weather
• World Clock

After the Macworld 2006 keynote, Steve Jobs also announced four new widgets (Ski Report, People Finder, Google Search, and ESPN), as well as significant updates to the Phone Book and Calendar widgets. All of these are available through the Mac OS X v10.4.4 update.
In addition, Mac OS X v10.5 "Leopard" released in late 2007, includes new widgets. One of these is Web Clips, which allows any user to turn a rectangular section of any webpage into a widget (This, however, only works with Safari). The widget updates as the website does, and all links and other interactive material in the widget's selection of the webpage works as if the website is being accessed from Safari. Another new widget is Movies, which allows users to find currently playing movies at local theaters, view trailers, and purchase tickets directly from Dashboard.

 Widgets on the desktop

To keep one or more widgets on the desktop, the Dashboard "devmode" must be activated. Enter the following into the Terminal:

defaults write com.apple.dashboard devmode YES

and then restart the Dock (and Dashboard):

killall Dock

After the devmode has been set, widgets dragged from the Dashboard will remain floating on the desktop, even after log out or shutdown. To move a desktop widget back to the Dashboard, simply reverse the process used to move it onto the desktop.
Another option is to use Amnesty Singles or Amnesty Widget Browser, shareware utilities that also allow the user to select which level (desktop, standard or floating) a widget occupies while it resides on the desktop. WidgetRunner is an open-source, freeware utility that also allows you to run widgets on the desktop and control the level at which they appear.

 Widgets on the iPhone OS

Apple has not, as of 2010, announced support for the installation of Dashboard widgets on the iPhone OS. Even though, in June 2008, an unannounced update of Dashcode that was packaged with the iPhone SDK allowed for the creation of iPhone-oriented web widgets, it is unknown if this most recent version of Dashcode would support the creation of AJAX-driven mobile widgets that could be installed natively on the iPhone OS.
It has been demonstrated by Erica Sadun that installing Dashboard widgets on a jailbroken iPhone OS is possible in theory, but most desktop-oriented widgets 1) are not oriented to usage or interaction on the iPhone OS's multi-touchscreen-oriented interface; and 2) rely on DashboardClient's widget JavaScript object, which is not part of the iPhone OS.

SEMANTIC WEB

Semantic Web

INTRODUCTION

              In the beginning, there was no Web. The Web began as a concept of Tim Berners- Lee, who worked for CERN, the European organization for physics research. CERN's technical staff urgently needed to share documents located on their many computers. Berners-Lee had previously built several systems to do that, and with this background he conceived the World Wide Web.

The design had a relatively simple technical basis, which helped the technology take hold and gain critical mass. Berners-Lee wanted anyone to be able to put information on a computer and make that information accessible to anyone else, anywhere. He hoped that eventually, machines would also be able to use information on the Web. Ultimately, he thought, this would allow powerful and effective human-computer- human collaboration.

What is the Semantic Web?

The word semantic implies meaning. For the Semantic Web, semantic indicates that the meaning of data on the Web can be discovered not just by people, but also by computers. The phrase the Semantic Web stands for a vision in which computers software's as well as people can find, read, understand, and use data over the World Wide Web to accomplish useful goals for users.

Of course, we already use software to accomplish things on the Web, but the distinction lies in the words we use. People surf the Web, buy things on web sites, work their way through search pages, read the labels on hyperlinks, and decide which links to follow. It would be much more efficient and less time-consuming if a person could launch a process that would then proceed on its own, perhaps checking with the person from time to time as the work progressed. The business of the Semantic Web is to bring such capabilities into widespread use

2. MAJOR VISIONS OF SEMANTIC WEB

" Indexing and retrieving information
" Meta data
" Annotation
" The Web as a large, interoperable database
" Machine retrieval of data
" Web-based services
" Discovery of services
" Intelligent software agents

THE SEMANTIC WEB FOUNDATION

The Semantic Web was thought up by Tim Berners-Lee, inventor of the WWW, URIs, HTTP, and HTML. There is a dedicated team of people at the World Wide Web consortium (W3C) working to improve, extend and standardize the system, and many languages, publications, tools and so on have already been developed.

The World Wide Web has certain design features that make it different from earlier hyperlink experiments. These features will play an important role in the design of the Semantic Web. The Web is not the whole Internet, and it would be possible to develop many capabilities of the Semantic Web using other means besides the World Wide Web. But because the Web is so widespread, and because it's basic operations are relatively simple, most of the technologies being contemplated for the Semantic Web are based on the current Web, sometimes with extensions.

The Web is designed around resources, standardized addressing of those resources (Uniform Resource Locators and Uniform Resource Indicators), and a small, widely understood set of commands. It is also designed to operate over very large and complex networks in a decentralized way. Let us look at each of these design features.

ysics research. CERN's technical staff urgently needed to share documents located on their many computers. Berners-Lee had previously built several systems to do that, and with this background he conceived the World Wide Web.

The design had a relatively simple technical basis, which helped the technology take hold and gain critical mass. Berners-Lee wanted anyone to be able to put information on a computer and make that information accessible to anyone else, anywhere. He hoped that eventually, machines would also be able to use information on the Web. Ultimately, he thought, this would allow powerful and effective human-computer- human collaboration.

Security in Mobile Database Systems

Security in Mobile Database Systems:
                The importance of databases in modern businesses and governmental institutions is huge and still growing. Many mission-critical applications and business processes rely on databases. These databases contain data of different degree of importance and confidentiality, and are accessed by a wide variety of users. Integrity violations for a database can have serious impact on business processes; disclosure of confidential data in some cases has the same effect. Traditional database security provides techniques and strategies to handle such problems with respect to database servers in a non-mobile context.


                For many businesses applications are going mobile that means using enterprise data in a mobile context, thus using a mobile DBMS. With these new developments the business data of an enterprise can be made available to an even larger number of users and a wider range of applications than before.

               To work on business data anytime and anywhere is the major goal pursued by developing mobility support in database context. The confidentiality of mission- critical data must be ensured, even though most mobile devices do not provide a secure environment for storage of such data.
Security requirements that apply to a central company database should apply similarly and in an appropriate manner to the parts of the database replicated on mobile devices in the field. A mobile database security infrastructure is needed to accomplish this goal. When developing such an infrastructure we can benefit from the results of traditional database security work. But we also need to adapt the existing techniques and strategies to the mobile context, and we need to develop new ones that attack certain issues specific to use of database systems in a mobile environment.

Book: Mobile Database Systems by Vijay Kumar

Web resources: Mobile database