Using a script to set the Copy Local flag to false

As with my previous post I recently came across a repeatable task that we will probably want to repeat in the future so with my aim from The Pragmatic Programmer I decided to automate it.

The problem was that an architecual requirement of this project was to rely on DependencyInjection for all library references. To help enforce this every project outside of the DI one would require the Copy Local flag on all references set to false.

I started doing this manually but figured out it'd take a long time to go through all 40+ projects and this would happen in the future. So automation time it was.

A quick web search did not show that anyone had solved this problem before so I figured out I would have to learn some Powershell and make it myself.

As csproj files are simply XML I did some research to find out how easy it was to manipulate XML in Powershell. It turned out this is one of Powershell's strengths. However the first implementation had issues with namesapces so I had to use the Select-Xml command introduced in Powershell v2.

Building the XPath queries was fairly simple. The one hiccup to remember is that csproj xml has a default namespace of "http://schemas.microsoft.com/developer/msbuild/2003" so you need to remember to use that and the msb namespace prefix when making your XPath queries. To specify the namespace in Select-Xml you use the -namespace option.

Select-Xml -namespace @{msb = $projectNamespace} -xpath $privateXPath

The next step was saving out the changes. This proved to be an initial roadblock as all the files were set to readonly. As we are using TFS you have to explicitly checkout the files before you can edit them. This resulted in me looking into how to use the TFS command line executable "tf.exe". This proved to be fairly nice as I could simply pipe the collection of csproj files I wanted checked out to a chunk of script that would iterate through the collection and execute the checkout command on each file with the provided TFS credentials.

I explicitly did not attempt to check in the changes as I want the user to review the changes and make sure the solutions are still working. This is something you'd run once a month to make sure the requirement is still being followed.

The final hiccup was that the .NET XML classes Powershell uses has an issue with putting in a default empty namespace whenever you create a new element. This caused the project to fail to load in VisualStudio as the namespace was incorrect. The fix for this was pretty quick and easy. Take the file and replace any occurance of xmlns="" with an empty string. This is accomplished in Powershell with line

(Get-Content $projFilenameFull) | Foreach-Object {$_ -replace ' xmlns=""', ""} | Set-Content $projFilenameFull

So my first non-trivial powershell script was a fun and fiddly dive into scripting all my troubles away. So far so good. ;)

SetCopyLocalInAllCsProjFiles.ps1

Event Handlers only firing once in Microsoft Office AddIns

I've just been working on a project where we were to create some AddIns for several versions of Microsoft Office. Now I knew there was a lot of bad blood around Office AddIns but thought they were being overblown as I finished off the 2010 AddIn without so much as a hiccup. The 2007 and 2003 AddIns however showed why Office has the reputation it has.

The problem I ran into was that I had to have several event handlers to catch two events. The opening of a new inspector and a simple button click. So I did what you'd expect to do and registered them in the startup methods.

Initial testing went fine as I started up Outlook and triggered one event, made some changes, restarted it and then tested the other event. It took a while until I tried to test both events following one another at which point I found only one would trigger and then both would even handler hooks would be forgotten and wouldn't rehook in until a restart of the application.

public partial class ThisAddIn
{
    private void ThisAddIn_Startup(object sender, System.EventArgs e)
    {
        Outlook.Explorer explorer = this.Application.ActiveExplorer();
        Outlook.Application app = (Outlook.Application)explorer.Application;

        app.NewInspector += new InspectorsEvents_NewInspectorEventHandler(Inspectors_NewInspector);
    }
}

After much searching I began to come across implications that the garbage collector was removing the references after the first event. I was at a loss at what to do until I came across another discussion where someone was having a similar problem and the response was to save the object in a class level variable to avoid the garbage collector from removing it.

A quick edit and some testing showed this to work reliably. So, if Office is only triggering an event once make sure there object references are stored somewhere the garbage collector won't go. And make sure to assign the object before you register the handler or the garbage collector will still find it.


public partial class ThisAddIn
{
    public Inspectors _appInspectors;

    private void ThisAddIn_Startup(object sender, System.EventArgs e)
    {
        Outlook.Explorer explorer = this.Application.ActiveExplorer();
        Outlook.Application app = (Outlook.Application)explorer.Application;

        _appInspectors = app.Inspectors;
        _appInspectors.NewInspector += new InspectorsEvents_NewInspectorEventHandler(Inspectors_NewInspector);
    }
}