Sunday, July 09, 2006

Choosing a wiki and a blog

I recently had to choose both a wiki and a blog. I also expected to find both functionalities within the same product or hosted service as they are not that different.

My requirements for the wiki were the following:
  • Topic articles with versioning, attachments and discussions;

  • Authoring of articles by invitation only, discussions opened to everyone;

  • Hierarchical organisation of topics, ideally presented like online help: table of contents, index, search;

  • Customisable UI (branding);

  • Full-text search;

  • Authoring using Word;

  • Preferably a hosted service with a friendly URL,

  • Ad-free.
My requirements for a blog were very similar, except:
  • Authoring of articles by the owner of the blog only;

  • Organisation by category and by date.
My first observation is that you apparently cannot have both within the same solution. is an invaluable resource to compare wiki software and two hosted solutions rise above average: jotspot and stikipad, although neither of them fulfils 100% of my requirements. Both products are basic but they do the job although authoring in Word, my top requirement, is not possible with these wikis.

I have not been able to find a comprehensive resource that compares blog software properly although there is some information at The well-known products I have come across are Community Server (formerly .Text), Moveable Type and WordPress. The top services are Blogger, MySpace and MSN Spaces. There is now also a Yahoo offering based on Moveable Type. My preference is Blogger because there is a Word plug-in which works reasonably well and it is free. The main objection is that Blogger lacks proper categories.

My conclusion is that there is still a lot to improve on wikis and blogs especially to streamline the authoring process and to make navigation more fluid.

Thursday, July 06, 2006

Why I rarely use ADO.NET Datasets

Have you ever seen these great presentations which teach you how to build a master-details web page in a few minutes without writing a single line of code using a combination of DataSets, TableAdapters, ObjectDataSources, GridViews and FormViews? There is a great one at

There are sound technical reasons not to use DataSets in ASP.NET applications due to their stateful nature. These reasons are explained by Frans Bouma in his blog at I have experienced other reasons not to use DataSets as a business layer.

The entity-relationship model (the way data is organised in database) rarely corresponds so perfectly (see the video mentioned above) to the way you are going to present it. You will need to go through various transformations, for example:

  • You may have an invoice which is constituted of items and you need to present the invoice total which is actually the total of all item amounts. This total may also need to be presented in several currencies.

  • You may have an N-N relationship between messages and contacts in your database, but you need to display a message with a To, Cc and Bcc fields which are separated lists of email addresses.
Data is rarely presented in the way it is stored in database and a business layer gives you the objects that you need between data and presentation, for example:

  • You need to store UTC dates which will have to be converted using the time zone defined in your user’s profile;

  • You need to store country codes which will have to be mapped to localized country names;

  • You need to store a document status as a byte like 0, 1 and 2, which will have to be mapped to an enumerated value like “draft”, “approved” and “rejected”.
You also need to validate data before storing it in database. You can use validation controls in your presentation layer, but their features are limited and it is good practice to implement business rules in a business layer.

So what should we do?

  1. Implement your data access layer (DAL) as stored procedures handling create, read, update and delete (CRUD) operations;

  2. Implement a business logic layer (BLL) in C# or VB.NET calling stored procedures using data readers and commands, which will achieve much better performances.
Then when do you use datasets?
  1. You only use datasets in rapid application development (RAD) scenarios, or when

  2. You have no other choice, for example when a component that you need (otherwise you would spend hours reinventing the wheel) requires datasets.