On Thu, Feb 25, 2010 at 3:02 PM, Aaron Bartell <aaronbartell@xxxxxxxxx> wrote:
So you get instant deployment of your application, but without all the CSS,
Javascript, HTML, server side/client side stuff that complicates web
programming.
And how well does that work when you are talking about an application that
has thousands of screens? How well does deployment work then? Are the
files big like the Flex .swf approach?
Even though we have much more bandwidth than 5 years ago, I think Microsoft
is shooting themselves in the foot by having compiled home grown objects
downloaded to the browser for every screen. They could have made a much
thinner and better performing veneer by only passing down a screen
definition to a render engine and keep all of the compiled programs on the
server so you never have to wonder if everybody is operating on the same
version of code.
The entire application is dowloaded, not a single screen. When you
create a SL project in VS you get a resulting .XAP file in the
ClientBin directory. That is a .zip file, only with a .xap extension.
Explaining in Java terms, the browser app runs in a JVM with the
runtime framework excluding parts that enable access to the local
machine. XAML, which originated with WPF is really, really, really
good for doing the GUI - what HTML and CSS are used for in web apps.
Using web services to put and get data to the server is all the rage
now as the way to design apps. Silverlight is dead center in that
style of app design. ( Not that using web services to this extent is
easy and without problems. This blogger has a lot of interesting
things to say:
http://wildermuth.com/ )
One of the really good things that MSFT is doing regards LINQ. Linq is
a replacement for SQL. A Linq query is compiled, composed, stored in
something called an "expression tree". That expression tree is a data
structure which can be transmitted over the wire from client to
server. ( the IQueryable interface is a combo of IEnumerable for
iterating thru a collection and an expression tree. ) The usage in
Silverlight is to have the C# silverlight client code contain a Linq
query to access the database. Parts of the .NET framework like WCF and
RIA services take that linq query in expression tree form, send it up
to the server thru a web service call, at the server convert the
expression tree to SQL, run the SQL against the database server (
note, that database server could be DB2 on IBM i ), get the resulting
result set, convert the result set to XML or whatever and send the
results back as the return value of the web service call. For paging
thru a large database, you use TAKE and SKIP in your LINQ code to
limit the number of rows returned.
www.silverlight.net has loads of videos that explain how it all works.
The forums that are hosted there are very busy and you get excellent
answers to your questions.
-Steve
midrange.com
