Microsoft Silverlight 3 is a cross-browser, cross-platform, and cross-device plug-in for delivering the next generation of .NET based media experiences and rich interactive applications for the Web. It extends the web development experience far beyond the limitations of plain HTML and JavaScript. Silverlight with its short hist ory of three versions now also includes many new features and functionality.

Silverlight has definitely raised the bar for browser plug-ins and development environments. Unlike Flash, Silverlight offers us a real IDE, true separation between design and development (the best designer isn’t necessarily the best programmer, and vice versa), real programming languages, and an efficient, high-performance, almost infinitely versatile browser plug-in.

Interesting features of Silverlight 3

· Fully supported by Visual Studio and Expression Blend

This massively changes the way a programmer looks at the code. There is negligible learning required with regard to programming language. A C# programmer can certainly write a code behind and easily create a XAML. Visual Studio 2008 incorporates designing a Silverlight application up to a certain limit, but designers looking for profound ‘looks’ can definitely seize help of an advanced IDE like ‘Expression Blend 3’ to create a attractive looking Plug-in.

· Out of Browser support allowing web applications to work on desktop

The Out of Browser support in Silverlight 3 enables developers to create Silverlight applications which can run both inside and outside of the browser.  By making some minor level changes to APPMANIFEST.XML, an application can be successfully run out of browser.

· Significant graphics improvements including 3D graphic support

Perspective 3D support in Silverlight will now allow developers to use 2D elements to create a 3D experience.  Perspective 3D is also a great way to better utilize screen real estate making the application user interface immensely attractive.

· Smooth video Streaming

Silverlight Streaming are services that allows users and developers to host their Silverlight content and apps with Microsoft, taking advantage of their extensive global network of datacenters and their content delivery network. Best of all, this service is free, and while currently it is only in alpha it allows users to upload up to 4GB of content, and to stream up to 1 million minutes of online video delivery at 700kbps of around DVD quality.

· Improvement in RIA development productivity

Silverlight 3 has over 60 high-quality, fully skinnable and customizable out-of-the-box controls such as charting and media, new layout containers such as dock and viewbox, and controls such as autocomplete, treeview and datagrid. Attention-grabbing element being that these controls come with nine professional designed themes and the source code can be modified/recompiled or utilized as-is. This means less development time and better looking app.

Silverlight has certainly made RIA simpler & as Microsoft puts it, it can surely “Light up the Web”

— Pranav Deo

xoriant

This is a Google tool used to build apps on the same scalable systems that power Google applications and run your web applications on Google’s infrastructure.

Google App Engine (GAP) enables users to build scalable web applications very easily and deploy them on Google’s application infrastructure in the same way that Google is deploying their own apps.

Traditional approach to Web application development:

• Setup Linux / Windows Machine
• Install and configure Webserver
• Install and configure Database
• Write your web application in any programming language
• Deploy app on server and make it available to the entire world

There is an extra overhead to maintain the server and manage databases. Also, if the application becomes popular then it has to handle huge traffic. Again, we need to analyze traffic to focus on popular areas of web application. So the cost of maintaining the application increases. Also, there are chances of hard-disk failure, server crashes, and so on.

All these things will not be required if we use GAP, because on completion, GAP deploys a web application on Google’s scalable infrastructure, so there is no possibility of hard-disk failure, server crash, and so on. Developers can mainly focus on the problem.

Lets see how to create a simple Web app, Soutout, which stores messages that are sent by a user in a database and displays it on a webpage in a sorted order.

Create directory Shoutout

mkdir shoutout

Create app.yaml

This is the main app configuration file.

application: shoutout
version: 1
api_version: 1
runtime: pythonhandlers:
- url: .*
script: main.py

Create file main.py

#!/usr/bin/env pythonimport wsgiref.handlers
from google.appengine.ext import db
from google.appengine.ext import webapp
from google.appengine.ext.webapp import template

class Shout(db.Model):
message = db.StringProperty(required=True)
when = db.DateTimeProperty(auto_now_add=True)
who = db.StringProperty()

class MyHandler(webapp.RequestHandler):
def get(self):
shouts = db.GqlQuery("SELECT * FROM Shout ORDER BY when DESC")
values = {'shouts' : shouts}
self.response.out.write(template.render("main.html", values))

def post(self):
shout = Shout(message=self.request.get("message")
, who=self.request.get("who"))
shout.put()
self.redirect("/")

def main():
app = webapp.WSGIApplication([
(r'.*', MyHandler)
])
wsgiref.handlers.CGIHandler().run(app)

if __name__ == "__main__":
main()

Create file main.html

This is the main page of app.

Run the app using Google App Launcher

<pre>    <h1>Shout out</h1>

    {% for shout in shouts%}

    <div class="container">

    <div class="{% ifequal shout.who ""%} row {% else %} row altrow {% endifequal%}">

    <div class="text message"> {{ shout.message }} </div>

    <div class="text normaltext"> from </div>

    {% ifequal shout.who "" %}

    <div class="text username"> Anonymous </div>

    {% else %}

    <div class="text username"> {{shout.who}} </div>

    {% endifequal %}

    </div>

    </div>

    {% endfor%}

    <form action="" method="post">

    <p>Message: <input type="text" name="message"/></p>

    <p>From: <input type="text" name="who"/></p>

    <p><input type="submit" value="shout"></p>

    </form>

You will see the full application running on localhost.

Deploy App on Google’s appspot

Click on Deploy in the Google app launcher to deploy it on Google. Then you can access it @ url: http://shoutout.appspot.com

- Vijayendra Bapte

admin

Believe me, developing in Ruby language is as fantastic and intuitive as the title sounds. [:)] Jokes apart, if you are in to web development and RoR has not crossed your radar yet, I would like to take the liberty to aver that you are significantly out-of-date. Fortunately though, if you keep reading this blog, you will certainly get a glimpse of the revolution in web development that open source communities have brought.

What can Ruby and Rails do for an organization?

What can any language-framework pair do for an organization? If there are answers popping up in your mind, be kind enough to consider the same for Ruby on Rails. RoR can do all that in a much easier, faster and cost effective way. On the other hand if you don’t know the answers yet, here is a glimpse of what RoR can do:

·         Build customer centric small/medium websites

·         Deploy a web product with advanced (web 2.0 -ish) features in a very limited time.

·         Create automated testing frameworks

·         Legacy Application extension, integration and migration

Why only Ruby-on-rails?

This is what the open source community has to say:

·Productivity gains: exponential savings because of smaller teams, more productivity, improved time to market.

· Easy development, easy maintenance : Lesser lines of code (10 times less than Java) , makes development faster and maintenance easier

· Agility: Rails is Agile, no matter how confused you are on your business concept, rails will help you visualize. It adapts to your changing requirements quickly and easily.

· Free: Its free and open source, can’t talk more on cost effectiveness.

· Powerful: Its can be simply put as what you SEEK is what you get.

Not Convinced? Check out RoR comparison with PHP, Java technologies, Perl.

For the more technically demanding soul, here is how ruby on rails score over others:

· Support for Representational State Transfer (REST) architecture

· SOA-like integration with enterprise systems

· Convention over configuration framework simplifies data management

· Don’t Repeat Yourself or DRY model based on Ruby’s inherent ability to provide Domain specific languages

· MVC (model view controller) design pattern

· Built-in testing at every level

· Capistrano / ActiveRecord migration

· AJAX support in any framework; runs on any Unix open source platform

What has RoR done ?

Testimonials: Some live projects singing the success story for ruby on rails.

Ø Amazon.com: Yes! The same Amazon.com

Ø Basecamp: project management tool by 37 signals

Ø Bixee: An upcoming Indian job portal

Ø BharathRentals: India’s car rental service

Ø Dimewise: personal finance management

Ø HBO Asia: HBO’s Asian broadcast online

Ø Scribd: online document sharing and publishing

Ø Shopify: e-commerce

Ø simplifyMD: digital chart room for small hospitals

Ø Twitter: Online community and social networking

admin

Now for the name…

With apologies to the people who make the cleanser and the detergent, legend has it that the original Ajax was the second most powerful of the Greek warriors at Troy. Even though he had some issues, his strength and skill in battle were second only to Achilles. In naming the technology Ajax, Jesse James Garrett gave the technology both Ajax’s strengths and issues… thus the name “AJAX”

Here are some reasons why AJAX is disruptive in the way people use the Web.

Why Ajax rocks

AJAX has two huge benefits:

1. Speed and invisibility makes for a very slick user experience.
2. The smaller server resources footprint helps server scalability.

I’ll explain these. If you post using AJAX, only the data (or parameters) that the server function requires is posted. In a login scenario, only the username and password strings (100 bytes maybe) are sent to the server and only a boolean value (1 byte) is returned. This means that only 101 bytes (excluding network handshaking traffic) is sent & received. If we were to create the same functionality using ASP.NET, all the state data is pushed to a server and the whole page is returned. Should the page use 20Kb of traffic, AJAX will save nearly 99.5% of this.

Further more, when using AJAX your web server and or db server (or whatever your config is) does not have to do any processing other than running the called function and returning the return value. No page load events, no xsl transform etc. This can have a huge impact in an enterprise environment.

When should I use it?

• On-the-Fly Form Data Validation
• Auto completion
• Master Details Operations
• Sophisticated UI Controls (widgets)
• Quick data store updates
• Real-time information feeds

When I shouldn’t

Simple forms.

Even though forms are the single biggest beneficiary of “Ajaxification,” a simple comment form, or submit order form, or other one-off rarely used form does not benefit from Ajax driven submission. Generally, if a form is not used much, or it’s critical to work properly, Ajax is not that helpful.

Search.

LiveSearch on blogs is more annoying than useful. There’s a reason that Google Suggest is staying in beta and not going on the front page of Google. Searching on Start.com or Live.com doesn’t allow use of the back button to see a previous search, or previous pages.

Basic navigation.

In general, driving basic site/application navigation using Ajax is an awful idea. Why would anyone want to spend time writing code to emulate the browser behavior when they could spend time making their application better? For basic navigating between documents, Javascript doesn’t help.

Replacing a large amount of text.

Ajax saves a complete refresh of the page, so small pieces of the page can be more dynamically updated. But if nearly everything on a page is changing, why not just request a new page from the server?

Display manipulation.

Even though it seems that Ajax is purely a UI technology, it’s not. It’s actually a data synchronization, manipulation and transfer technology. For maintainable and clean web applications, it’s a good idea not to have Ajax/Javascript manipulate the interface directly at all. Javascript can stay separate and simply manipulate the XHTML/HTML DOM, with CSS rules dictating how the UI displays that data. See this post for a simple example of using CSS instead of Javascript to control display.

Useless widgets.

Sliders, drag and drops, bouncies, mouse gestures, whatever. Mostly these widgets can be replaced with more intuitive controls, or eliminated altogether in favor of simplicity. In picking colors, maybe a slider widget is useful to pick the exact shade. But in picking a price point in a store, a slider to pick the price to the cent is just overkill.

Why Ajax sucks

Bookmarks

Using AJAX to asynchronously load bits of content into an existing page conflicts with the way we are used to navigate and create bookmarks in modern browsers. Because viewing some part of the page information no longer corresponds to a newly loaded page, the browser history and bookmarks will not be able to restore the exact page state.

History

Also, clicking the Back button in a browser might not have any effect, since the URL was unchanged (even if parts of the page were changed). To overcome these problems you must implement a way to save the current page state programatically so that it can be restored later on, when called from a bookmark or from the browser history.

Accessibility

The biggest concern with AJAX is accessibility. This is because not all browsers (especially older ones) have complete support for JavaScript or the XMLHttpRequest object. Some of the visitors do have browsers with the required features, but they choose or have to turn off JavaScript support. When you design the application you must make sure that a fail-safe solution exists for those users, so it can be accessed by anyone. Further more, the way to access and use the XMLHttpRequest object in Internet Explorer and other browsers is different, which leads to a fork in the code and the need to treat each case separately.

How it works…

Following are the essentials for working with AJAX:

HTML, CSS, XML, any server-side technology and JavaScript

Ajax Frameworks

1. Pure JavaScript libraries – provide core remote scripting.
2. Server-based AJAX libraries – generate the AJAX code from your server application.

Following are some of the most popular AJAX libraries:

• AjaxPro
• ASP.NET AJAX Extensions
• Direct Web Remoting (DWR)‏
• Google Web Toolkit (GWT)‏
• Dojo
• Prototype
• xAJAX

Who’s using Ajax

Rightly said, images speak louder than words…

Getting started…

Here are some handy references to get started…. NOW :

So start rockin…!!!And stay tuned for my next blog on the how to implement Ajax in the real world…

–Gautam

admin