Dynamic dataaccess with Webmatrix Webpages

by dotnetnerd 11. October 2011 22:06

Today I went to a talk by Hadi Hariri about dynamics which was arranged for the ANUG user group in cooperation with the goto conference. The talk happened to fit very well with the first topic I had planned for my series on Webmatrix Webpages, which is dataaccess.

The talk was about not fearing dynamics, and some of the scenarios where it can provide some benefits over static types. Some of the scenarios Hadi talked about were DTO’s, ViewObjects and for DataAccess, which is exactly what WebMatrix WebPages utilizes.

The flood of Micro-ORMs

Over the last year or so a lot of so called Micro-ORMs have seen the light or day with some of the more popular ones being Simple Data, Dapper, PetaPoco and Massive. The reason for their popularity is that they provide a sense of simplicity in the vietnam of computer science as Ted Neward put it.

Each of these ORMs have their own focus, strengths and weaknesses – and some are more “Micro” than others. Compared to NHibernate or Entity Framework they are all very simple to get started with. For quite a few of them part of the strength is the return of good old SQL in stead of LINQ or some other abstraction.

WebMatrix.Data

When a new Webmatrix Webpages project is created it comes with its own Micro ORM out of the box. The ORM allows queries and commands to be executed, which are expressed as SQL statements. For queries data is returned as dynamic objects. So a regular query could be done like this.

var db = Database.Open("myDatabase");
dynamic user = db.QuerySingle("SELECT * FROM Users WHERE User_Id = @0", 123);

The big advantage of this approach is that you can select any fields, calculate fields, join with other tabels to your hearts content and you won’t have to write a class to represent each shape of the data returned. This also means that we can use the power of SQL and that we avoid overcomplicating things.  Because the distance from database, to query and then to the view is so short working with dynamic objects is not a problem. So if your domain is not too vast and complex life is good.

Doing inserts and updates is equally easy, but it is one of the areas where I find the ORM lacking. Most annoying is that it does not handle converting null to DBNull. Also while you do get extention methods to convert strings as int, DateTime etc, there is no option to get null instead of the default value of the datatype. So the code tends to get cluttered with parsing and conversions – if you don’t write the extentions yourself.

Clean Ajax

A nice surprise for me was how easy it is to expose data as JSon to enable Ajax when working with WebPages. All you have to do is create a WebPage that retrieves data, pass it to JsonEncode and write it to the response like this example shows.

var json = Json.Encode(user);
Response.Write(json);

Life does not get more simple than this, and it leaves you with this smooth feeling when moving data between server and client.

Conclusion

The dataaccess bits for WebMatrix have been fun to work with, and it has given me a great sense of freedom to get things done, without having to do viewobjects, mappers and a bunch of configuration.

The fluidity of working with dynamic data, and doing ajax certainly has opened my eyes with reguards to the value that this kind of framework can provide. “The return of SQL” has also reminded me, that LINQ is not all rainbows and smiles. The power of micromanaging a JOIN statement and doing UPDATES and deletes should not be overlooked.

Using the right tool for the right job is still the key phrase though. It has been a good match for this project I am working on, but I would not want to use it for an enterprise application. Testability is clearly not a goal of the framework, refactoring is error prone and when complexity increases the code tends to get messy.  So if anything I will argue that it proves that the place for WebMatrix is hobbyists, simple projects, startups and prototyping.

What is the Matrix?

by DotNetNerd 29. September 2011 20:50

Currently some of my spare time is spent building an application using WebPages in WebMatrix and Visual Studio Express, which has been fun and given me the chance to look at webdevelopment and quality from a different angle. WebMatrix is a free Microsoft tool that is targeted at hobbyists and developers doing lightweight development, by enabling users to build websites either from scratch or on top of open source sites such as Umbraco, Screwturn or dasBlog. All in all there currently 59 sites to choose from spread across the categories blogs, CMS, eCommerce, forums, galleries, tools and wikies.

matrix-5fed_imageCopy_ae5cb424_crop_ae8179a7

The application I am working on is built from scratch, because the requirements don’t really fit with any of the generic systems. For this purpose WebMaxtrix has the option to build a completely custom site using a framework called WebPages which utilizes the Razor viewengine.

At first look when you see WebPages, you might think of classic ASP or PHP, because it also works by mixing markup and code in the same file. I will admit that at first this made me cringe – as I think most professional developers who are used to building enterprise scale applications will. Having read a bit more about it on various blogs over the last year it cought my interest for some specific scenarios. The point to me is that it is quite powerful for quickly putting together applications where the complexity is manageable. So to get a startup on its feet quickly, to do a proof of concept or for those who dabble in webdevelopment as a hobby it can definately provide good value.

I my case it is actually a startup that I am looking to help my brother with – who just happens to dabble a bit in webdevelopment once in a while. So for a guy who understands the basics of the web, but is not familiar with the amount of abstraction that is involved in building an ASP.NET or MVC application, WebMatrix and Webpages seem like a good fit. Having implemented the first couple of pages and a basic structure I am pretty happy - hopefully I won’t wake up and think why, oh why, didn’t I take the blue pill.

And what is Quality?

A word that is often heard when discussing a framework like this is “quality” or more specifically lack there of. For a while I have actually thought about writing a comment on what quality is, because it is something all agree that they can and will deliver, but mostly when it comes time to define it people start arguing. If anything the tendency is that people argue that the skillset they personally possess is what defines quality. TDD guys argue for testability and code coverage, designers argue touch and feel of a site and so on and so forth.

Personally I always think back to one of my teachers who said that quality is to which degree a product lives up to what the customer expects. Which is pretty close to what google comes up with when referring to wikipedia and the definition based on the ISO 9000 standard which defines it as “degree to which a set of inherent characteristics fulfills requirements”. While I think this is a good definition it also leaves me with a sense that an important aspect is overlooked. As Henry Ford said “If I'd asked customers what they wanted, they would have said a faster horse". This could be interpreted to mean that the most important thing is guiding the customer and telling them what they never knew they always wanted. So my personal definition is:

Quality exceeds the customers original expectations and fulfills the requirements to a high degree. 

At least, that is the experience I want as a customer, and it is what gives me that amazing feeling of victory when we are able to provide it.

Reflecting on the topic of the blogpost I think that WebMatrix and WebPages can indeed deliver quality. I think so for a number of reasons, the obvious ones being if the requirements revolved around speed of delivery or the customers ability to participate with a basic set of knowledge about webdevelopment.

Now what?

This blogpost has been quite unusual for me, because it contains no code at all! Rest assured though, because my intent is to turn this into a little series of blogposts – I just wanted to lay the foundation. The current idea is that I will look at how deep the rabbithole goes, by digging into some of the building blocks of a WebPages application. Hopefully I will be uncovering what WebPages can be used for, and also some  techniques and tools that might be used in other contexts.

Who am I?

My name is Christian Holm Nielsen, and I work as an independent consultant, in Denmark, where I write code, give advice on architecture and help with training. On the side I get to do a bit of speaking and help with miscellaneous community events.

Some of my primary focus areas are code quality, programming languages and using new technologies to provide value.

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