July 1st is right around the corner and for e-commerce based companies in Washington this means that Senate Bill 5089-2007-08, or the "Stream Lined Sales Tax" bill takes effect.  In short this means that online retailers in Washington need to collect destination based sales taxes.

Washington state is not alone on this.  In fact Washington is joining 21 other states under the Streamlined Sales and Use Tax Agreement (SSUTA).  Notice the "Use Tax" in the wording.  This is what empowers the state to tax based off destination shipping address.  This is just like when you go to register a boat in Washington that you purchased in Oregon, you are paying a use tax, which is legal according to the constitution.

Fortunately the Supreme Court ruled in Complete Auto Transit vs Brady that states cannot tax interstate commerce, which really means that an online retailer in Washington does not have to collect California state sales tax, unless that online retailer also has offices in California. 

With the passage of Stream Lined Sales Tax bill there are several winners here:

• Washington state tax coffers.
• Local brick and mortars.
• Lawyers and possibly accountants.
• Tax integration consultants.

Online retailers that only have an online presence previously had a nice loophole around collecting state sales tax since they are generally located in only one or two states.  Chain based brick and mortars (like Barnes and Nobles) that decide to go online are at a district disadvantage since they have presences in most, if not all states, which means they need to collect sales taxes from online sales in just about every state.

The absolutely ridiculous part of this law is the extra complexity to ensure the right local sales tax is collected.  In other words the shipping address dictates the sales tax rate, and in Washington each locality has its own sales tax rate with local governments setting local sales tax.  This means the sales tax rate can vary widely, and you, Mr. e-tailor need to figure it out.

Fortunately we all have zip codes here in the US which we can use to figure out the local sales tax rate, unfortunately we also have zip+4.  Well, zip+4 isn't bad, in fact its actually useful, but most people have no idea with their zip+4 is.  I know I definitely fall into that category.  And wouldn't you know it, the shipping zip code isn't enough to figure out the correct sales tax, you need the zip+4.

We can't start asking customers for their zip+4, since they probably don't have any idea what the last 4 numbers are, but we can ask them for their address and regular zip code which we can then use in a cleansing call to the USPS webtools APIs.  This address cleansing call, as you might now suspect, fills in the zip+4 based off the street address and zipcode.

With zip+4 in hand we can query our local database of sales tax rates and charge the customer the locally correct sales tax rate.

Just today I realized that I'm using a fair number of Visual Studio 2008 addins. Visual Studio is starting to look more and more like Eclipse to me, a general work bench of tools. Which is surprising considering how painful it can be to write a Visual Studio addin in the first place.

So what addins am I using today?

• VisualSVN - Seamless and painless, I almost forget that its there.  If you use SVN and Visual Studio, do yourself a favor and fork over the $50 for it.
• ReSharper 4.0 - My refactoring/template tool of choice.  Coding without Re# is like digging a hole without a shovel.  I also use it to drive my unit tests, but TestDriven.NET is superior IMO.
• TargetProcess - This shows all my current tasks and bugs right from within Visual Studio so there's no need to jump over to my web browser to find work or update status.
• GhostDoc - I use this to bootstrap any XML documentation I might need.
• ActiveWriter - I just installed this, so we'll see how it goes.  I'm going to use this to map some entities to a new view or two.

Yesterday I blogged about detecting IIS version from MSBuild, or more accurately, OS version.  Detecting whether my MSBuild script was running on XP allowed me to skip the application pool creation that would otherwise error out the build script.

What I didn't expect was that the website creation task would actually succeed in creating a secondary website in IIS 5.1.  I vaguely remember from other blog posts how its possible to programmatically create secondary websites in IIS 5.1, but didn't realize it was so easy.  Just for the record the following snippet also works against IIS 6 and 7.  The following build script does exactly that.

That takes care of new site creation, only optionally creating the site if it doesn't already exist, but always modifying it to ensure consistent settings.  The final piece we need is to stop running "Default Web Site" and start the new site.  IIS 5.1 can only run one site at a time so this is why we stop the default site and explicitly start the new site.

Once the script finishes we can check in inetmgr to see the new IIS 5.1 site right along side the default web site.

Are you wondering why I would go to all this trouble of monkeying around with IIS for development?  Well you should be.  The reason is that the Visual Studio web server does not support ISAPI filters, and since I'm doing URL rewriting at the ISAPI level, running under IIS is the only option.

I've been using the Microsoft SDC tasks to deploy IIS websites, and for the most part this has worked well once I grabbed the latest source from CodePlex; I ran into a few bugs that have been fixed since the last release.

Anyways, I've run into an annoyance with regards to local development builds on Windows XP.  Most of our devs are still using XP for their development platform which as you may know uses an old version of IIS - IIS 5.1.

• No app pools
• Single site only
• No SSL

So, what does this have to do with the SDC tasks?  Well, I want the MSBuild script to fail gracefully with an intelligent error message when run on Windows XP.  Something like:

This version of IIS is not supported, IIS 6.0+ is required.

I couldn't find a decent built-in supported way in MSBuild to get the IIS version, let alone the operating system version.  You would think this would be supported without resorting to C#, but I couldn't find a way.  So what I ended up doing was using the command line "ver" command and piping that to a text file and then reading it back in.  Here's what that looks like:

I needed to create an xml fragment that had optional elements that was serialized from a class.  The optional elements were integers and decimals, types that are not nullable by default in .NET.  Well, we can wrap those types in Nullable<T> and then add an another ignored property that helps out the .NET serializer.

[XmlElement(Order = 10)]
public decimal? Height
{
    get { return height; }
    set { height = value; }
}

[XmlIgnore]
public bool HeightSpecified
{
    get { return height.HasValue; }
}

With the additional HeightSpecified property, the XmlSerializer will only write out the Height property element if its non-null.

Initially I tried using [XmlElement(IsNullable=false)] on the Height property, but that ended up throwing an InvalidOperationException when I went to serialize my class.