Feature is always activated for features targeted at a web site (web)

Finding: Feature scoped at "web" is always activated when deploying using Visual Studio 2010.  Regardless of the "Activate on default" setting, - thanks Matthew.

SharePoint 2010 explained in pictures - looks like a great idea

http://blogs.msdn.com/b/sharepointpictures/

CKSDev tool issue - The custom tool SPMetalGenerator failed

Problem: When adding a SPMetal Definition (CKSDev) item in visual studio, the SPMetal proxy generation fails with the error message: The custom tool 'SPMetalGenerator' failed.  Object reference not set to an instance of an object.

Hypothesis: CKSDev item template is failing, next I tried SPMetal from the command line and received the "Invalid File Name" error.  I had previously fixed this issue and here is the link.

I check the issue using the browser:

Resolution: Delete the list showing the Invalid file name error.  I could not do it from the UI so I used PowerShell.

More Info:
http://sp2010uk.blogspot.com/2010/08/issues-with-site-columns-content-types.html

NullReferenceExcepetion when viewing/editing an existing list item after the list instance has been deployed

Problem: When viewing or editing and item in a list, I receive an application error (NullReferenceException).  This happens when I redeploy a list, my list is defined using site columns, content type and the list definition is based on the content type.

My ULS logs contained the following information:

Failed to cache field with id

Unable to open Lookup list 'Lists/xxxList'.[Error was 0x8007....]
System.NullReferenceException: Object reference not set to an instance of an object.   at Microsoft.SharePoint.Publishing.FieldCache.TryGetValue

Initial Hypothesis:  ULS logs show me that a lookup list is not being found.  By examining the columns on the list instance I can see they are not being created correctly.  My initial thought was my xml was wrong, once it was reviewed and I found it to be correct I realised it was a caching issue.

Resolution:  Clear the Visual Studio Cache

1. Right click on "Project" in Solution Explorer and click "Retract";
2. Close Visual Studio 2010; and
3. Open the "Project" in Visual Studio 2010 and "Deploy" the solution. 

SPMetal naming conventions - good practice

Problem: The Linq to SharePoint proxy generates properties using the display name of the column, additionally spaces are removed.  If you use a friendly short name you get duplicates.  The 2nd instance is appended a integer.  If you add a column with the internal name "Advert Title" and it's display name is "Title", SPMetal generates 2 properties namely: Title (the default column in all lists) and Title0, not ideal to differeintiate in code.

Resolution:  Make the display name more specific to avoid the scenario.  I.e. "Publication Title" would become the property "PublicationTitle".

Tip: Update 18 Oct 2010 - SPMetal does not like spaces in the url to the site that it generates off.  Error the web at 'http://demo.dev/sites/my site' could not be found

http://blogs.flexnetconsult.co.uk/colinbyrne/2010/07/13/SPMetalDoesntLikeSpaces.aspx

Extending SPMetal - Retrieving Attachments from SharePoint Lists

Problem: LINQ to SharePoint does not support attachments by default.

Hypothesis: Traditional Server Object Model approach to retrieving a specific list item’s attachments.  Approach is shown below:

Resolution: Use a partial class as described by Andrew Connell to use Linq to SharePoint to work with attachments. You could hydrate the attachment (SPFile objects) in the parital class but I choose not to, in case someone in the development team used the extended mapped property for retrieving a large list. This uses the Server object model and the hydration process is extremely heavy.  This method allows me to know if there are attachments, how many and where I can get them.  With this information I only get the specific SPFile objects if I need to work with the object.  Outlined are the steps to extend LINQ to SharePoint to retrieve attachment associated to items in a list.

1) Extend the SPMetal generated proxy class

2) Get a specific item using the LINQ to SharePoint model and using the String array returned by the extended class, get the file objects using SharePoint’s server side object model.

Tip: attachments is a string array, not an array of SPFile objects. The attachements.UrlPrefix property can be used to hydrate the SPFile objects for the list item.

Tip: I upload attachments using the Dialog framework point to attachfile.aspx as it does all the work for me.
_layouts/attachfile.aspx?ListId={5555D16F-5559-4CE4-555E-F5B0E9DC5555}&IsDlg=1&ItemId=



SQL Server 2008 Service Pack 2 Released

Overview: Technet news flash email letter announced the release of SQL Server 2008 Service Pack 2 today.  I think it's been out a few days. 
http://go.microsoft.com/fwlink/?LinkId=196550
I have installed on my development machine - no issues.  If you are on Windows 2008 upgrade to SP2.  New installs should still use SQLServer 2008 R2 and ignore this Service Pack.