Removing Duplicate SPList Objects From Typed Collections

Company | Articles & Research | Services | Software |

Our Company

All SharePoint Articles

Security

Development

Accounting / Dynamics

AIS / Dynamics GP

Other

Consulting Services

Freeware / Experiments

Applications	WebParts	Security Components
SharePoint Field Diff And Copy Utility * Written In January, 2012 SharePoint Security Scanner * Written In January, 2012 SharePoint Kerberos Buddy * Written In Feburary, 2011 BioPoint: SharePoint Biometric Authentication * Written In September, 2007 SharePoint List Security Migrator * Written In August, 2007 SharePoint Anti-Keylogger™ * Written In April, 2006 S.M.A.R.T SharePoint™ * Written In May, 2006 SharePoint Sentinel™ * Written In June, 2006 SharePoint Scrubber™ * Written In July, 2006 SharePoint Safeguard™ * Written In August, 2006	SecureSilverlight For SharePoint * Written In January, 2010 Simple Rollup WebPart For SharePoint * Written In Novemember, 2009 SimpleChart For SharePoint * Written In December, 2009 SimpleSecurity For SharePoint * Written In June, 2009 CrytoCollaboration (Encryption) * Written In June, 2007 Sample AJAX Rotator WebPart * Written In July, 2007 Sample SharePoint Redirector WebPart * Written In August, 2006 WFE Server Name WebPart * Written In January, 2006	PDF IRM Protector * Written In December, 2010 ADAM Role Provider * Written In February, 2007 Universal Provider Framework * Written In April, 2007

Contact

Removing Duplicate SPList Objects From Typed Collections

One of my friends had a slight dilemma in his code this morning where he had a recursive loop, subject and constrained by some limit logic, which iterated through SPList objects in an arbitrary SPWeb and returned a large typed collection of SPList objects. The collection was afterward used for massaging out some specific SPField values, assimilated later by a detached business application.

One difficulty that he was running into was the occurrence of duplicates that were taking place during the generation of the collection. He was questioning if it was workable to inspect and eliminate duplicate SPList objects that occur before returning the final SPList collection.

In order to do this, we of course necessitate a unique identifier for each object, so it makes sense to use the SharePoint generated SPList.ID property which guarantees a unique value. Within the method, we are creating two other collections, a temporary typed dictionary object which will hold the ID values to later act as a guard clause, as well as a provisional SPList collection which will provide return allocation.

PLAIN TEXT

C#:

public static List<SPList> CheckAndRemoveDuplicateSPList(IEnumerable<SPList> inputList)
{
Dictionary<Guid, int> tempDictonary = new Dictionary<Guid, int>();
List<SPList> tempListCollection = new List<SPList>();
foreach (SPList list in inputList)
{
if (!tempDictonary.ContainsKey(list.ID))
{
tempDictonary.Add(list.ID, 0);
tempListCollection.Add(list);
}
}
return tempListCollection;
}