news:1141513027.491213.79900@i40g2000cwc.googlegroups.com...
> We are in the middle of a project that requires both a web GUI and web
> services.  We have elected to go with a 3-tier (data, business,
> presentation) model using typed datasets as the data layer.  We are not
> using either the sql data source or the object data source on the page,
> just rolling our own, old school style.  The customer(s) will are all
> business partners with reliable and fast connects and there is no
> expectation of ever having a consumer direct option.
>
> We are posting this since we have been unable to find any real examples
> of this type of implementation and are looking for help in poking /
> filling the holes.  Who knows you may be looking for an example, so
> here goes.....
>
> Data Layer
>
> Straight vs2005 generated typed datasets for all updatable data access.
> For read only reporting and display data access we will use untyped
> datasets.  We have not had much success with data readers so we will
> shy away from them if possible.  You can generate a strongly typed
> dataset so we won't bore you with the details.
>
> Business layer
>
> Accepts requests from pres layer or web service layer and interacts
> with the data layer.  Any necessary validation, conditional
> enforcement, or other business logic is checked / applied.  In many
> cases this is just a pass through if we have done a good job with
> required fields, getting and setting nulls for value types, and client
> side validation.  In others, especially calls from the web services,
> there will be a bit of processing going on in the Biz obj.  This layer
> is not creating a business object from the typed dataset, only
> interacting with the datasets as they pass through.
>
> Presentation layer
>
> Is "Aware" of the typed datasets, but has no idea where they come from,
> and is limited to reading data from them and plugging data into them.
> All data access must go through the biz layer, even if just a pass
> through or simple lookup.  The pages are smart enough to do most of the
> required field checking and input validation, however any conditional
> biz logic or other complex enforcement is left to the biz object.  We
> are currently storing the typed datasets in the viewstate.  As
> mentioned before the users all have reliable connectivity.  We don't
> load any data that we are not willing to put on the page so there are
> no data security issues.  All of our updatable datasets are dealing
> with 1 or 2 rows data so they don't really bloat the viewstate all that
> badly.
>
> We have implemented several pages and so far it seems to be working.
> The typed dataset is living up to the billing of reducing both design
> and run time errors due to the increased use of intellisense.  The
> performance so far is great and we are already reaping the benefits of
> reusable code blocks, both in the data and biz layers.
>
> So there it is - shoot it down before it multiplies.  We think we are
> on the right track - but since we built the track - what else would
> we think?  I would be glad to provide some code samples upon request
>
> Thanks in advance.
>