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New Post: Is this project keep updating?

VictorWoo — Mon, 15 Apr 2013 02:24:03 GMT

Is this project keep updating?
Where is the newest info?

New Post: Is this project keep updating?

VictorWoo — Mon, 15 Apr 2013 02:24:01 GMT

Is this project keep updating?
Where is the newest info?

New Post: Some questions regarding definitions and where to put use case implementation.

fahadjaved — Sat, 13 Apr 2013 20:29:06 GMT

Hi Peter,

Have you got answers to your questions? If so can you share it with me. I have pretty much similar questions in my mind.

Thanks

New Post: Some questions regarding definitions and where to put use case implementation.

atemoya — Mon, 07 Jan 2013 16:10:39 GMT

Dear App Arch Guide team,

I read most of the “Microsoft Application Architecture Guide 2^nd Edition”, with emphasis on the first 14 chapters, where my following questions refer to. At first I want to thank you (and the many other contributors) for the great guide, it already helped me very much in finding out how to structure my layers (together with the Layered Architecture Sample by Serena Yeoh). I posted my questions on stackoverflow.com some days ago (because the discussion site on codeplex seemed not to be active any more), but it was closed as “too vague” (not my opinion, of course). Since my main objective is to get a qualified answer, I wanted to ask you kindly whether you could help me; if not directly, feel free to forward this to any of your co-authors if more specialised on this topic. I expanded the list of questions now to all which popped up to me during reading of the guide. I know they are many, but I hope they are interesting feedback for you, too.

Many thanks in advance for any help and again for this great guide!

Acronyms used by me:

Application logic (AL)

Business logic (BL)

Domain logic (DL)

Business components (BCs)

business workflow components (BWCs)

business process components (BPCs)

business entities (BEs)

business logic components (BLCs)

What exactly are BPCs, how do they differ from BEs, as both implement business logic: “Chapter 10: Component Guidelines” > Business Layer Components: BWCs: “…the application can use this to perform a business process…”, “BWCs work with BPCs that instantiate and perform operations on BWCs.” BEs: “BEs, or – more generally – business objects, encapsulate the business logic…”.
This question seems to have something to do with “application state” vs. “entity (domain object) state” and how to differentiate between these two. Could you provide some examples for each of the two, since I have only a vague imagination what the differences could be?
Are BCs the general term for business workflow components (BWCs), business process components (BPCs), business entities (BEs), utility classes etc., as suggested in Chapter 12: “Designing Business Entities” (“Examples of these components include business logic components, business entities, business process or workflow components, and utility and helper components”) or are they all EXCLUDING the BWCs and BEs, as suggested by the layer diagram e.g. on page 84, where they are depicted separately? Or are there two different definitions of BCs used here, one like in chapter 12 where BWCs and BEs are included and the other like in Chapter 14, Step 5 “Design BCs to support Workflow” where they are separated from BWCs in the context of BizTalk Server like in the layer diagram?
Contradictory definitions of term BLCs: In chapter 10: “Component Guidelines” > “Business Layer Components”, BLCs are defined as encompassing BWCs (and also BPCs? Please see question 1 and clarify.) and BEs. However, in chapter 12: “Designing BCs” > “Step 1 – Identify BCs Your Application Will Use”, they are not (listed on the same level as BEs and BWCs instead). So which definition is the correct one?
Same section in chapter 10 as in question 3: “Application logic” (AL) vs. “business logic” (BL): “Business logic is defined as any application logic…” i.e. in this definition AL is the more general term. This however contradicts Randy Stafford’s definition in Fowlers book which is: "Business logic" is the general term, can be subdivided into "domain logic" (purely concerned with the problem domain) and "application logic" (“sometimes referred to as “workflow logic”, although different people have different interpretations of “workflow”.”). (see Fowler, "Patterns of Enterprise Application Architecture" > "Service Layer"). Could you be more precise what you mean with AL and tell me what is AL which is not BL (being a subset of it in your definition)?
Same section: “business logic components should not contain any behaviour or application logic that is specific to a use case or user story. BLCs can be further subdivided into the following two components (BWCs and BECs)”. So where do I implement the use cases? “It depends? J” In the article cited in question 4, Randy Stafford writes: “In the operation script approach a Service Layer is implemented as a set of thicker classes (“services”) that directly implement application logic but delegate to encapsulated domain object classes for domain logic”. I think this is the approach followed in the “Layered Architecture Sample” by Serena Yeoh, i.e. the use cases are in the service layer?
Finally: I always thought “workflow” and “use cases” were somewhat related? I did nowhere find something about how these terms relate (or do not) to each other. Could you explain that to me a) in general, b) specifically concerning MS Workflow Foundation?

Many thanks for your patience if you read this far,

Peter.

New Post: Updates

m4tthall — Wed, 08 Jun 2011 09:10:54 GMT

Are any further updates planned for this site?

New Post: Is Web Architecture Pocket Guide a subset of App Arch Guide?

fujiy — Fri, 08 Oct 2010 11:45:31 GMT

Is Web Architecture Pocket Guide a subset of App Arch Guide?

New Post: Error message to be displayed to the user

rbware83 — Tue, 22 Dec 2009 21:59:06 GMT

The document has been really helpful, thank you.

One area that I have not been able to find much information on, beyond exception handling, is handing error messages. And when I say error message, I mean the message that at the highest level is displayed to the user. I want to store these messages in a central location, but I am not sure the best method of doing so.

I am currently working on an ASP.NET MVC site, and I could place all the error message in the controllers to be passed to the UI. It seems it would be better if all these error message and their content were in one central location. Maybe an ENUM would be well suited here, but then it has to be customized to be able to handle the string text of the message, so it does not feel natural.

I am looking for some different input here, and how others may have done this.

New Post: Scalenet.pdf update planned?

dalepres — Wed, 15 Apr 2009 21:17:41 GMT

Is there any planned update for scalenet.pdf (Improving .NET Application Performance and Scalability)at http://msdn.microsoft.com/en-us/library/ms998530.aspx? This came out in 2004. While it is still useful, it is hard to use it as a reference in performance and architecture discussions without being challenged that we're 3 levels later on .Net Framework since then.

Regards,

Dale

New Post: Durable Services for Mobile

dasblonde — Sat, 11 Apr 2009 19:09:20 GMT

This document states:
If you need durable state, you can use the durable storage (introduced in .NET 3.5) or implement your own custom solution.

If this is referring to WCF Durable Services here (not durable storage) then this is not so simple to support in the Mobile client since you can't use context-aware bindings OOB. You would have to roll your own client implementation to get this done. I suggest that if this document is to suggest an implementation, it would be good for readers to know what is supported OOB and what is "roll your own". Otherwise we could be guiding people to think that things are supported as they are for rich clients. Just a suggestion.

New Post: WS-ReliableMessaging Support for Mobile?

dasblonde — Sat, 11 Apr 2009 19:05:40 GMT

This document states:
You can use WS-Reliable Messaging to implement reliable end-to-end communication, even when one or more Web services intermediaries must be traversed.

I don't think that WS-RM is supported for mobile, since we can't use WSHttpBinding. Unless you want to roll your own WS-RM protocol.

New Post: Silverlight For Mobile Doesn't Exist?

dasblonde — Sat, 11 Apr 2009 19:02:51 GMT

My understanding is that Silverlight for Mobile does not exist. Am I wrong? If not, will this document be updated to remove that section?

New Post: Correct Link for Data Access Layer Video

Gooch — Mon, 23 Feb 2009 02:09:58 GMT

The correct link for the Data Access Layer Video is:
http://www.codeplex.com/AppArch/Wiki/View.aspx?title=Video%3a%20Data%20Layer%20Layer&version=3

New Post: Prism - I don't see the pattern...

Billkrat — Tue, 27 Jan 2009 22:20:21 GMT

Probably a poor choice of pun ;)   Prism effectively utilizes patterns such as Supervising Controller MVP and Separated Presentation. The point is more towards seeing Silverlight as a fat client than thin, and like patterns, architectures should twist and turn with the times.

With new and emerging technologies we have to continually revise and twist existing patterns
   + MVC -> MVP
   + ASP.NET MVC (Model2) from MVC
   + Presentation Model from MVC/Application Model.

Enter stage left Prism (aka CompositeWPF); permitting us to create fat clients on client side with the language we love so much - .NET.

The Presentation -> WCF -> Service Layer -> BLL -> DAL meets conventional programming needs but not for Prism.   With Prism, modules are in different assemblies (which can be loaded dynamically). To use Silverlight as a simple (but elegant) UI is a waste of client processing power resulting in unnecessary round trips - much of the application business logic can be in our Prism applications keeping our WCF services more generic and reusable across multiple applications, e.g., an Employee service that knows how to get data from numerous corporate application databases and resources such as ADS.

What became problematic on a recent sprint was the addition of our first module's Web Service.   A problem because there is no SvcUtil.exe for Silverlight (yet) and we are tied to L2S so we are forced to go with "Add Web Service" and as such we can only reference our entities from our data layer (yes, we have a IBLL->IDataProvider in our silverlight module). Not to mention it's configuration file; this file coupled with the Website configuration file and the requirement to give the main assembly a copy of the ServiceReferences.ClientConfig (Prism V2 Drop 8) which results in three configurations to maintain for a simple, single module application; this application will grow into a multitude of modules.

Some may think that three configuration files in itself doesn't seem so bad, but wait until you have to move them through a cycle of Development, Staging and Production servers.   With every new module that accesses WCF Services comes additional configuration files to maintain.

---

In the absence of an authoritative source and guidance (if it's out there I can't find it) the solution I'm toying with is pretty basic - when dealing with a fat client we're taught that you should have a pattern (PresentationModel, MVP, etc) that consumes a reusable service - so it starts to look like this:

Presenter -> IService -> IBLL -> IDataProvider  ~~~ WCF -> Service layer -> BLL -> DAL

Where the IService, IBLL and IDataProvider are configured in the application's Unity configuration section.   Unfortunately with "Add Web Reference" we can only reference our entities from the implementation of our IDataProvider so I'm researching the fastest method to project the results into a Shared library entities; this way our IService and IBLL are oblivious (as they should be) to the data object model - for example if I want to have my IDataProvider dynamically set to an implementation that operates from an Isolated Storage data file if available.

Any guidance from the gurus on this matter would be appreciated.

New Post: New type of solutions

rboucher — Wed, 14 Jan 2009 21:27:06 GMT

Hi plpasta,
This was beyond the scope of what we examined. We haven't really brought in any 3rd party frameworks by name with the exception of logging for mobile clients because some of our experts felt it was important enough to give a few examples. We were going for something more timeless. As external frameworks can change and we just recommend "3rd party" solutions in certain cases or ignored the issue in favor of stating the principles that a framework should utilize. We didn't want to refer to much in print. We often even pass over our own offerings, leaving them at the bottom as reference and out of the main principles.

But, we do recognize the power there. Afterall, we do have our own dependency injection framework (Unity).

Anyone in the community is welcome to comment the pages where these frameworks are relevant. Just comment the wiki pages on http://www.codeplex.com/AppArchGuide .

Rob

New Post: But what about the database?

rboucher — Wed, 14 Jan 2009 21:00:29 GMT

Thank for the link. We agree that database design is certainly important. However at 387 pages, we had to draw the line somewhere. Proper database design is a huge topic in itself.
I've passed on this feedback to p&p management for either a KB topic on this site or perhaps more guidance in the future.

Rob

New Post: Where is ASP.NET Model-View-Presenter (MVP)?

rboucher — Fri, 09 Jan 2009 23:04:46 GMT

Hi Chris,
We've certainly mentioned this in the Guide itself and even done videos on it. See the main site http://www.codeplex.com/AppArch and scroll down to videos. We haven't covered ASP.NET MVP in depth in the Main guide, other than to mention it, because it's actually too low level for most architectural discussions in the guide.

Rob

New Post: Guidance Explorer Online Store

rboucher — Fri, 09 Jan 2009 22:14:03 GMT

Hi Matt,
Sorry we are later on answering this thread. Yes, this content will go into GE in some form. J.D. Meier, the leader of this project, is actually the inventor of the GE concept. After the guide is complete, we work on getting the content in GE. It can sometimes take some time. We've got a new revision of GE out with some bug fixes.

For those reading this thread who don't know, GE is guidance explorer. It's a tool used to slice, dice, store, and even modify and edit our content via Rich Client application (or a web version which is less functional than the Rich Client app). Since we write guidance that's highly modular, we can "nuggetize" it the guidance so it fits in the tool. For more information see http://www.codeplex.com/GuidanceExplorer for more information.

Rob

New Post: How about Release via Wiki?

rboucher — Fri, 19 Dec 2008 06:29:21 GMT

The codeplexwiki is on the http://www.codeplex.com/apparchGuide site along with the download of the PDF guide. It's right on the main page

New Post: How about Release via Wiki?

hardywang — Wed, 17 Dec 2008 22:46:23 GMT

In this case I don't really support anoymous editing, because P&P team is the expert.

The benefit of Wiki is fast releasing, I don't need to wait for certain amount of time to see next version, but I can always see P&P team's most up-to-date change right away, plus like what you said comments on certain section of article.

BWT, where is the CodeplexWiki?

New Post: How about Release via Wiki?

rboucher — Wed, 17 Dec 2008 22:10:57 GMT

Hi Hardywang,
We do release to Wiki (codeplex wiki) on this site and you can comment on the botom of various pages.

What I'm hearing is that you'd like an anonymous wiki like Wikipedia where people can edit the pages themselves?

Rob