Considering UI implications is an important part of SOA strategy,
because undue influence from the presentation side can result in
services that are still too tightly coupled to the needs of one
particular user interface. Many IT projects are still rooted in user-
facing systems. What a user may need in their interface is going to
be different than what may typically be exposed in a system-to-system
interface associated with a services tier.
As Michael suggests, there needs to be a separation between concerns
at the presentation tier and concerns at the services tier. This
implies that there will need to be some form of data transformation/
manipulation in between the UI and the services tier that allows
things to be exposed in a more consumable manner for the UI.
I once had someone ask me about whether a user-centered design
philosophy is in direct conflict to what SOA tries to achieve.
Personally, I think the two can be complementary, but only if you do
have good separation of concerns. If the approach is still around
monolithic or silo'd applications, conflict can certainly arise. If
presentation services are treated separately from general business
services, they can exist in harmony.
-tb
On May 13, 2007, at 7:53 AM, Michael Poulin wrote:
I agree with JP Morgenthal, Ajax can collaborate with Web Services
and it will look like Web 2.0 +SOA=...
Actually, the issue here is not in technologies but in the
usability pattern, if you want.
In the Presentation layer, user experience is not bound any more to
the fragmented web pages and page flows running exceptionally in
synchronous mode; in the Business layer, there is no need for
special components but only services; in between layers, there is
no need any more or traditional Web application' facades,
adapters, etc.) but just data transformation and service
subscription utilities. Data transformation is bi-directional:
from/to the Business Interfaces/User interface format to/from
business services' interfaces format. That is, Web apps shrink into
data transformation facilities.
What services are used behind the point of subscription does not
matter. It may be real SOA or just Web Services. In the former
case, Ajax and similar technologies open the door to the service-
oriented UI on Web platform (it is nothing new for Java Swing or
visual VB/C++/C#).
An important point here is that Business Interfaces/User interface
requires a special type of business services that encapsulate
business logic implemented in the business actions themselves. This
is different business logic than implemented in, e.g., business
rules. It is intersecting to look at these services from the SOA
perspective.
- Michael
JP Morgenthal <[EMAIL PROTECTED]> wrote:
You don't need SOA for RIA. You just need a Web Service. Web
Service does not equal SOA. You can use Web Services without any
forethought as to reusability. In fact, if you read my blog entry
on the matter (www.avorcor.com/morgenthal) you will see that I had
to mediate a well-designed SOA with an XML server pages facade just
to simplify the UI
__________________________________
JP Morgenthal
President & CEO
Avorcor, Inc.
46440 Benedict Drive
Suite 103
Sterling, VA 20164
(703) 444-1130 x 4: Office
(703) 554-5301 : Cell
[EMAIL PROTECTED]
__________________________________
SOA success is just a click away...
On May 11, 2007, at 4:23 PM, Ashish Deshpande wrote:
All,
I've been experimenting with building visual web applications – I
used frevvo andRestlet (I work for frevvo). I've posted a
couple of blog articles about my experiences and I was wondering
how other people are building visual web applications with SOA,
and particularly your experiences using Ajax. (BTW, I used REST
for my web applications but I consider it to be a simpler subset
of SOA.)
You can find much more including diagrams, examples and source
code at:
How do I use my brand new WOA?
Visual REST apps: Part 1
Visual REST apps: Part 2
I'd be very interested in your thoughts: is Ajax + SOA = RIA (Rich
Internet Application) ?
Thx,
-Ashish
Luggage? GPS? Comic books?
Check out fitting gifts for grads at Yahoo! Search.
