Though Customer has already added custom logging mechanism in “publicSPRemoteEventResult ProcessEvent(SPRemoteEventProperties properties)” nothing has been generated, Which gave me the clue that it is failing well before.

1. Analyzed the ULS log and make sure the call to RER service has been triggered

2. Analyzed the IIS log file on RER server and found that IIS   is getting a hit from SharePoint and calls to Services/AppEventReceiver.svc is recorded

 3. Then to get more info, enabled the FREB log to trace the WCF calls for status code 100-600. (Seehow to enable FREB here).
 

4. Going thru FREB log, As expected it has failed in IIS pipe line

5. Navigated to “Compact View” in FREB xml file and Looked at GENERAL_REQUEST_ENTITY & “GENERAL_RESPONSE_ENTITY_BUFFER” event which recorded the Request SOAP from SharePoint and Response SOAP from RER

6. Since “includeExceptionDetailInFaults” has not been enabled on RER side, it is showing “The server was unable to process the request due to an internal error.  For more information about the error, either turn on IncludeExceptionDetailInFaults (either from ServiceBehaviorAttribute or from the <serviceDebug> configuration behavior) on the server in order
to send the exception information back to the client, or turn on tracing as per the Microsoft .NET Framework SDK documentation and inspect the server trace logs"

7. Injected the below highlighted xml block to web.config of RER and tried to install the app again.

<system.serviceModel>
    <bindings>
      <basicHttpBinding>
        <!--Used by app for SharePoint-->
        <binding name="secureBinding">
          <security mode="Transport" />
        </binding>
      </basicHttpBinding>
    </bindings>
    <protocolMapping>
      <add binding="basicHttpBinding" scheme="https" bindingConfiguration="secureBinding"/>
    </protocolMapping>
    <behaviors>
      <serviceBehaviors>
        <behavior>
          <serviceDebug includeExceptionDetailInFaults="true" />
        </behavior>
      </serviceBehaviors>
    </behaviors>
</system.serviceModel>

8. It has now included the exception stack trace with where it is failing

9. Fixed the issue.

When SharePoint is configured with Trusted Identity provider, you might get a error "Operation is not valid due to the current state of the object" while accessing the page after a successful authentication.

Error is :

Microsoft.SharePoint.IdentityModel.SPFederationAuthenticationModule.GetReturnUrlFromResponse Operation is not valid due to the current state of the object

Root cause

One of the root cause is the Identifier Claim coming from AD FS is empty. If you have configured with AD, then go to AD and give the proper value in AD Attribute.

• Terms - A term is the central object in the taxonomy system.
• Termset - A collection of  related terms in a hierarchy is a termset.
• Labels - Terms have to be  known by a bunch of different names.
• Groups - Groups in the  taxonomy system are simply collections of termsets that share a common security assignment.
• Keywords - Free hand strings(folksonomy) is a simply flat list of strings.
• Open Termsets - Open termset allow content editors to add new terms to a hierarchy at content authoring time.
• Closed Termsets - Open termsets does not allow content editors to add new terms to a hierarchy at content authoring time.
• Default Label - The label used for the term set when it is selected and displayed in the user  interface.
• Description - A brief description of what the term is used for.
• Available for Tagging - A flag indicating if the term can be used to tag content.
• Language - Each term can be  translated to multiple languages (depending on the language packs  installed in the SharePoint farm).
• Synonyms  Some terms may be different depending on  the users and the context.

Programming:

 SPS2010 includes a robust application programming interface (API) that developers can use to create and manage taxonomies. The API is found in the Microsoft.SharePoint.Taxonomy.dll assembly. You will find this reference in C:\\Program Files\\Common
Files\\Microsoft Shared\\Web ServerExtensions\\14\\ISAPI\\Microsoft.SharePoint.Taxonomy.dll. This has the following namespaces which we have to know while programming

• Microsoft.SharePoint.Taxonomy.TaxonomySession
      
• Microsoft.SharePoint.Taxonomy.TermStore    

• Microsoft.SharePoint.Taxonomy.Group    

• Microsoft.SharePoint.Taxonomy.TermSet
      
• Microsoft.SharePoint.Taxonomy.Term
      

Inorder to program "Term", we have to fetch the Session, refer the TermStore, get the Group & TermSet and code on Term object which is in the above order. 

 TaxonomySession session = new TaxonomySession(SPContext.Current.Site);

TermStores termStore = null;

            if (this.session.TermStores.Count!= 0)

            {

                this.termStore = this.session.TermStores["Test"];

                this.group = this.termStore.Groups.GetByName("TestGroup");

                TermSet termSet = this.group.TermSets[termSet];

                Term term = termSet.Terms[<<Guid>>];

            }

We will see more in the following post. Thanks.

Happy coding...

CQWP does not have the PageFilter and Pagination functionatilies. By extendign the CQWP, It can be achieved through the XSLT. Pagination is very often used feature for the content displaying webpart.

Pagination

We saw how can we use "ProcessDataDelegate" in the earlier one. By using the same functiontionality we have to achieve the pagination and it should be compatible with XSLT.  ProcessDataDelegate pass resultset of CQWP as the DataTable.

1) Add a column "No" in to DataTable and assign the number for earch row.

2) By using the RowFilter we can filter the row from the starting number to end number what we want. Below is the logic to achieve this.

 int currentPage = 1;
 this.pagesCount = (int)Math.Ceiling((double)dt.Rows.Count / this.ItemsPerPage);

 int startItemNumber = (currentPage - 1) * this.ItemsPerPage;

 int endItemNumber = startItemNumber + (this.ItemsPerPage - 1);
 dt.Columns.Add("Number", typeof(int));

 for (int i = 0; i < dt.Rows.Count; i++)
{

dt.Rows[i]["Number"] = i;

}

dt.DefaultView.RowFilter = String.Format(CultureInfo.CurrentCulture, "Number >= {0} AND Number <= {1}", startItemNumber, endItemNumber);

 dt = dt.DefaultView.ToTable();

 return dt;

 Above logic will return the filtered DataTable

3) How to display in XSLTBy using ModifyXsltArgumentList method we have to add one more parameter
 "argList.AddParameter("PaginationString", string.Empty, pagingHTML)"
4) we have declear a string varibale pagingHTML and coin the HTML to display the pages 
 i.e By using  "builderHtml.Append("<a href=\"#\">" + paginationPrevious + "</a>");"
5) After it should be passed to xslt parameter as mentioned above.

PageFilter

PageFilter functionality will be used when you are provisioning a page with particular field and based on the field value CQWP should filter the data. Again by extending the ProcessDataDelegate, we can achieve this.

1) Add to dropdown into Editor webpart

2)  Display  the current page content type field in first dropdown display, and current site fields in next dropdown

3) Bring the values in to DataProcessing delegate

4) Fetch the value like below

                SPField sourceField = SPContext.Current.Item.Fields.GetFieldByInternalName(this.PageFilterField);
                SPField targetField = SPContext.Current.Site.RootWeb.Fields.GetFieldByInternalName(this.TargetFilterField);

5) Compage the value  and filter it from DataTable.

Happy coding..

Extending CQWP

These are more important steps while extending user friendly CQWP.

• Creating Tool Part for CQWP
• Processing data
• Passing data to XSLT


Creating Tool Part for CQWP

When extending new functionality to CQWP, new functionality should be easily configurable thourgh toolpart for Content Authors.  ContentByQueryWebPart is public class which can be extended , but ContentByQueryToolPart  is a sealed class which could not be extended. But it can be achived by adding our ToolPart class to GetToolParts() override method and returning the ToolPart[] arrary with our toolpart class.

1. Extend CQWP and make MyCQWP : ContentByQueryWebPart
2. Create new MyToolPart class inherting from  Microsoft.SharePoint.WebPartPages.ToolPart. (See this how to create tool part in MSDN)
3. Add your controls in tool part class(Example Adding "More Link" text and "More Link" Url, or Filtering based on some field....)
4. Add this Tool part into MyCQWP by adding into tool part array.      

       public override Microsoft.SharePoint.WebPartPages.ToolPart[] GetToolParts()

        {

            List<ToolPart> parts = new List<ToolPart>();

            parts.AddRange(base.GetToolParts());

            MyToolPart myToolPart = new MyToolPart ();

            parts.Add(myToolPart);

            return parts.ToArray();

        }

 Processing data

Next step is processing the data in CQWP with additionaly fuctionality which we provided in Tool part. CQWP give a delegate where it gives the resultset as a DataTable, where we need use for our custom functionality. We should register our delegate in OnInit method
 

protected override void OnInit(EventArgs e

{
base.OnInit(e);
this.ProcessDataDelegate += this.ProcessDataItems;
}

  public DataTable ProcessDataItems(DataTable data) {
////Process the DataTable....
try
{
//// put your custom functionality for processing DataTable like filtering, massaging data itmes
}
catch
{
}

return data;
}

Now CQWP will display the massaged data in page.

Passing data to XSLT

 We have achieved the CQWP to display our own data. Now next question comes, how to display our own text inside CQWP like "More Link" and "More  Link Url", which we have configured ToolPart. For that we shoudl touch the "

protected override void ModifyXsltArgumentList(ArgumentClassWrapper argList) function, where we have to add our params into it.

protected override void ModifyXsltArgumentList(ArgumentClassWrapper argList) {
base.ModifyXsltArgumentList(argList);
if (argList != null) 
{
argList.AddParameter("MoreUrl", string.Empty, this.MoreUrl);
argList.AddParameter("MoreText", string.Empty, this.MoreText);
}
}

 After adding this, we have to handle it in XSLT file, Open the "ContentQueryMain.xsl" in and add your params

  1) Compile time constants
  2) Run time constants


Compile time constants

Compile time constants are replaced with exact value when it compiled. what is it mean? Well. When we declare a variable 


 public const int iUserCount = 500;

and when we do some operation like

for (int iCount = 0; iCount < iUserCount; iCount++)

Then x will actually get replaced in the compile time and if you see in the IL using assembler it will be 
for (int iCount = 0; iCount < 500 ; iCount++)

Run Time constants

When we use "readonly", it will not put the actual value instead of reference. Thats why it is slower than Compile time constants. But there is an advantage.
public readonly int iUserCount 

1) With Const we can only declare primitive types and string. But with readonly we can declare all the types.
2) Runtime will be resolved at the runtime


Why we need very cautious about "const".


We should be very cautious about "const" when maintenance come into picture. The reason is, assume you have an assembly "A" where you have declared the
public const int iUserCount = 500; 

And in the Assembly "B" you are using the iUserCount in 

Later when you modify the iCount value as 1500 in assembly "A", 
then you have to recompile the assembly "B" also. 
until unless it will have the same 

 for (int iCount = 0; iCount < 500 ; iCount++) 

and produce wrong result. So maintenance become nightmare. 
So prefer readonly then const.

Happy Coding

While installing SP2010 on Windows7 for development, you might face this error "Could not access the Search administration database"

Exception: System.Runtime.InteropServices.COMException (0xC0041236): Could not access the Search administration database. A generic error occurred while trying to access the database to obtain the schema version info.  

Resolution:

Check your SQL Server Client10.0 configuration settings, by going to Start Menu -> SQL Server 2008 R2 -> Configuration Tools -> SQL Server Configuration Manager.

And check whether Share Memory option is enabled under "Client Protocols". It should be enabled.

Run again the SharePoint 2010 Products Configuration Wizard

Happy Coding