How to implement the CreatedBy, CreatedOn and UpdatedBy, UpdatedOn properties in a business class

I would like to promote a KB article, which may be interesting for users who are just getting started with our application framework. This information is actually not new and it was already available in the FAQ and Reference sections of our online documentation as well as the support knowledge base.

https://www.devexpress.com/kb=K18352

I must emphasize that there are actually many ways to implement such auditing properties, and your current code may differ from what we show. For instance, one may declare it as "internal  set {...}" or use the PersistentAlias attribute. Just do not be at all concerned. 

You are welcome to share your own implementations in post comments - maybe we can vote for the most concise and beautiful code, eh?:-P

How to implement and where to put business logic in XAF?

We have recently rolled out another update of our online documentation where we isolated and detailed one of the most common questions beginners have. Actually, the answer was already present in the docs, KBs and examples and we have just reorganized these learning materials so that you need to know is in one place.

Please be sure to check out the new concepts section at eXpressApp Framework > Concepts > Data Manipulation and Business Logic even if you are an experienced XAFer. This is not the final version and we have several updates planned for this section in the near future.

If you are getting started with the framework, then running through the eXpressApp Framework > Getting Started > Basic Tutorial (SimpleProjectManager Application) tutorial will be a prerequisite.

I also want to remind you that our What's New documents for new product versions include the lists of documentation changes (What's New In Help) where you can find other interesting stuff like this, e.g.: this is what we have in v14.2.5 for XAF.

Please let me know what you think in comments to this blog. Thanks in advance!

A Gentle Introduction to XAF - Watch the webinar recording on YouTube

Watch the recent webinar (~1h 20m) made by Seth Juarez (Analytics PM at DevExpress) a couple of days ago.
eXpressApp Framework (XAF) was something new for Seth until this July when we seated together  for 4 days to help him learn the product architecture, its features and specifics and eventually build a basic XAF app from scratch. Seth is a fast learner and very good speaker, so I believe you will enjoy watching this webinar recording and learning more about Seth's experience and getting a better understanding of what XAF essentially is and how it can help your development.

Even if you are not new to XAF, I still recommend watching this, because first, it is a chance to have some fun - thanks Seth!:-) and probably hear of some framework aspects you have not yet tried or figured out well.

It seems that all of my peers in the US (Oliver, Paul, Julian, etc.), are interested in XAF recently:-). Please check the latest blog from Seth Juarez (a PM for DevExpress Analytics division - follow him on Twitter at @sethjuarez):

Building a Simple Contact Application with XAF

I hope you like it and find it helpful, especially if you are not using XAF yet and considering its benefits for one of your future LOB apps. BTW, a more detailed and comprehensive getting started tutorial can be found at http://www.devexpress.com/Products/NET/Application_Framework/getstarted.xml 

Nested vs Root ObjectSpace

I think that the information I've just posted in http://www.devexpress.com/issue=Q472381 will be helpful for new XAF users:

"When designing XAF many years ago we implemented the following behavior:
- if an object is aggregated (when this object is a part of a master object), a nested ObjectSpace is created for it, because this object should not be physically saved to the database until its owner is saved itself.
- if an object is not aggregated (when this object can exist separately), a separate ObjectSpace is used for it.

The same behavior is enforced when opening Views for existing objects, and not only for new ones.

This can be controlled via the virtual GetObjectSpaceToShowViewFrom method of the XafApplication class.
To learn more about ObjectSpace and Views in XAF, check out the following documentation:
http://documentation.devexpress.com/#Xaf/clsDevExpressExpressAppBaseObjectSpacetopic
http://documentation.devexpress.com/#Xaf/CustomDocument2611

P.S.
In Entity Framework, there is no such entity as NestedObjectSpace or UnitOfWork at all."

 

XPO Session vs XAF ObjectSpace (for starters only)

I think that the explanation in the http://www.devexpress.com/issue=Q415894 ticket willl be helpful for people who get started with XAF:

"In XPO, if you use Session and want to save your changes, you should either call the Save method of your persistent object or use the CommitTransaction method of the Session class.
If you use UnitOfWork (it is a descendant of Session), then you should call its CommitChanges or CommitTransaction methods. You can also use the Save method to mark your persistent object as modified.
In XAF, there is a similar entity called ObjectSpace. It uses UnitOfWork internally when XPO is used for data access. To save data in an ObjectSpace, use its CommitChanges method.
To create a new object, use the CreateObject method of the ObjectSpace class. Of course, you can access the underlying XPO session via ((XPObjectSpace)theObjectSpace).Session .
So, these are the same scenarios, just implemented differently.
I hope this clarifies things for you."

These concepts are now more detailed in the XAF documentation at eXpressApp Framework > Concepts > Data Manipulation and Business Logic

What are the equivalents of traditional buttons, menu, toolbar and navigation items in XAF?

I believe that the explanation provided in the http://www.devexpress.com/issue=Q416185 ticket will greatly help understand the concept of commands - Actions in XAF, especially for newbies.

«Умные» формы eXpressApp Framework (XAF). Часть 2 — Метамодель UI приложения

http://habrahabr.ru/company/devexpress/blog/153755/

«Умные» формы eXpressApp Framework (XAF). Часть 1

http://habrahabr.ru/company/devexpress/blog/140323/