Design Advice for an HTA based Crud App...

Question

Hi,

I am developing a framework for various in-house CRUD apps. I've considered several MS technologies (WPF, Access, WinForms, ASP.NET) and have settled on ASP.NET MVC with HTA+Jquery for the client. My reason for doing so is that I need a way to write and deploy quick one-off GUI apps as well as maintaining more robust apps that are expected to have a long life time.

Firstly, I would appreciate some thoughts on the relative merits of using ADODB on the client side versus ADO.NET on the server side. I'm leaning towards ADODB since I'll have client side access to the SQL Server (I've already written a js library that handles interacting with ADODB). However, I can see how developing a RESTful service may eventually be useful.

Secondly, I need to incorporate reporting capability into the system. I can use SQL Server reporting services or crystal reports but the users have grown accustomed to some older applications that use VBA to write reports in Word; so I'm considering using WordML to write the reports.

Thanks.

Answer 1

Database Access

If you need a thin client, then it's probably better to stay away from directly accessing the database from within the client.

The main issue is that you will introduce a high dependency on a specific network architecture and both your ASP.Net application and the HTA will be highly dependent on the database.

Instead I would prefer to sever the dependency on direct line of sight to the DB and have the data to be handled by the server.

This has a few advantages:

• for many small changes to the db, you're probably only going to have to update the ASP app.

• if you ever need your client app to be functional over the internet (say because some users are going to an outside meeting, need to work from work or your company open a new branch) then you won't have to rewrite your thin client.

• you keep better control over access to the resources: only let the ASP app talk to the database and filter what comes in/out of it.
  This will saves you having to implement all security on the client: the ASP app becomes the guardian of the database. It's a much better way to secure information and it gives you a lot more control.

Reporting

For reporting I'd use the server again rather than implement complex reporting capabilities in the client itself.
The problem is that you'll always going to get limited on the client if you're using an HTA and don't want to start having to install dependencies on each user's machine.
You'll end-up building a thick client in no time...

If you're using ASP.Net there are plenty of really good reporting tools that will make your life much easier and allow your users to get nice reports in Excel, Word, PDF, etc without you having to code these features yourself.
Crystal Reports is ok, but there are better and simpler alternatives, for example the Developer Express Report engine is pretty easy to use.