ASP.NET

Share Point Server Interview Questions (Part1)

Note: A LOT of these questions are specific to SharePoint 2007, and won't have applicability for SharePoint 2003!

1) What are the two base classes a WebPart you are going to use within SharePoint 2007 can inherit from?

There are two base classes that a WebPart which is going to be consumed by SharePoint can inherit from, either the SharePoint WebPart Base class or the ASP.NET 2.0 WebPart base class. When inheriting from the SharePoint WebPart Base class your derived WebPart class will inherit from Microsoft.SharePoint.WebPartPages.WebPart. When inheriting from the ASP.NET 2.0 WebPart base class your derived WebPart class will inherit from System.Web.UI.WebControls.WebParts.WebPart. It is considered good practice to use the ASP.NET WebPart base class since the old base class is meant for backwards compatibility with previous version of SharePoint; however there are four exceptions when it is better to leverage functionality from the SharePoint WebPart base class:

Cross page connections

Connections between Web Parts that are outside of a Web Part zone

Client-side connections (Web Part Page Services Component)

Data caching infrastructure

2) What are the differences between the two base classes and what are the inherit benefits of using one over another?

The difference is the Microsoft.SharePoint.WebPartPages.WebPart base class is meant for backward compatibility with previous versions of SharePoint. The benefit of using the SharePoint WebPart base class is it supported:

Cross page connections

Connections between Web Parts that are outside of a Web Part zone

Client-side connections (Web Part Page Services Component)

Data caching infrastructure

ASP.NET 2.0 Web Parts are generally considered better to use because SharePoint is built upon the ASP.NET 2.0 web architecture. Inheriting from the ASP.NET 2.0 base class offers you features that inherit to ASP.NET 2.0, such as embedding resources as opposed to use Class Resources for deployment of said types.

3) What is the GAC?

The GAC stands for the global assembly cache. It is the machine wide code cache which will give custom binaries place into the full trust code group for SharePoint. Certain SharePoint assets, such as Feature Receivers need full trust to run correctly, and therefore are put into the GAC. You should always try to avoid deployment to the GAC as much as possible since it will possibly allow development code to do more than it was intended to do.

4) What is strong naming (signing) a WebPart assembly files mean?

Signing an assembly with a strong name (a.k.a strong naming) uses a cryptographic key pair that gives a unique identity to a component that is being built. This identity can then be referred throughout the rest of the environment. In order to install assemblies into the GAC, they must be strongly named. After signing, the binary will have a public key token identifier which can be use to register the component in various other places on the server.

5) What are safe controls, and what type of information, is placed in that element in a SharePoint web.config file?

When you deploy a WebPart to SharePoint, you must first make it as a safe control to use within SharePoint in the web.config file. Entries made in the safe controls element of SharePoint are encountered by the SharePointHandler object and will be loaded in the SharePoint environment properly; those not will not be loaded and will throw an error.

In the generic safe control entry (this is general, there could be more), there is generally the Assembly name, the namespace, the public key token numeric, the typename, and the safe declaration (whether it is safe or not). There are other optional elements.

6) What is the CreateChildControls () method? How can you use it to do something simple like displaying a Label control?

The CreateChildControls method in Web Parts is used to notify the WebPart that there are children controls that should be output for rendering. Basically, it will add any child ASP.NET controls that are called instantiating each control with its relevant properties set, wire any relevant event handlers to the control, etc. Then the add method of the control class will add the control to the controls collection. In the relevant WebPart render method, the EnsureChildControls method can be called (or set to false if no child controls should be called) to ensure that the CreateChildControls method is run. When using CreateChildControls it implies that your WebPart contains a composition of child controls.

In order to create something like a label control in Create, you would create a new label control using the new keyword, set the various properties of the control like Visible=True and Fore Color = Color. Red, and then use Controls. Add (myLabelControl) to add the control to the controls collection. Then you can declare EnsureChildControls in the Render method of the WebPart.

7) What does the Render Contents method do in an ASP.NET 2.0 WebPart?

The render contents method will render the WebPart content to the writer, usually an HtmlTextWriter since Web Parts will output to an HTML stream. Render Contents is used to tell how the controls that are going to be displayed in the WebPart should be rendered on the page.

*** Side Question: I got asked what the difference between CreateChildControls and the Render Contents method. The CreateChildControls method is used to add controls to the WebPart, and the Render Contents method is used to tell the page framework how to render the control into HTML to display on a page.

8) What is the WebPartManager sealed class? What is its purpose?

The WebPartManager sealed class is responsible for managing everything occurring on a WebPart page, such as the Web Parts (controls), events, and misc. functionality that will occur in WebPartZones. For example, the WebPartManager is responsible for the functionality that is provided when you are working with moving a WebPart from WebPartZone to WebPartZone. It is known as the “the central class of the Web Part Control Set.”

*** Side Question: I got asked how many WebPartManager controls should be on a page. In order to have Web Parts on a page there has to be just one WebPartManager control to manage all the Web Parts on the page.

9) What is a SPSite and SPWeb object, and what is the difference between each of the objects?

The SPSite object represents a collection of sites (site collection [a top level site and all its sub sites]). The SPWeb object represents an instance SharePoint Web, and SPWeb object contains things like the actual content. A SPSite object contains the various sub sites and the information regarding them.

10) How would you go about getting a reference to a site?

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C#:

1. oSPSite = new SPSite("http:/server");

2.

3. oSPWeb = oSPSite.OpenWeb();

11) What does a SPWebApplication object represent?

The SPWebApplication objects represents a SharePoint Web Application, which essentially is an IIS virtual server. Using the class you can instigate high level operations, such as getting all the features of an entire Web Application instance, or doing high level creation operations like creating new Web Applications through code.

12) Would you use SPWebApplication to get information like the SMTP address of the SharePoint site?

Yes, since this is a Web Application level setting. You would iterate through each SPWebApplication in the SPWebApplication collection, and then use the appropriate property calls (OutboundMailServiceInstance) in order to return settings regarding the mail service such as the SMTP address.

Side Question: I got asked if there are other ways to send emails from SharePoint. The answer is yes, there is. You can use the Send Mail method from the SPutility class to send simple emails, however it is not as robust as using the System.Net.Mail functionality since it doesn’t allow things like setting priorities on the email.

13) How do you connect (reference) to a SharePoint list, and how do you insert a new List Item?

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C#:

1. using(SPSite mySite = new SPSite("yourserver"))

2. {

3. using(SPWeb myWeb = mySite.OpenWeb())

4. {

5. SPList interviewList = myWeb.Lists["listtoinsert"];

6. SPListItem newItem = interviewList.Items.Add();

7.

8. newItem["interview"] = "interview";

9. newItem.Update();

10. }

11. }

14) How would you loop using SPList through all Share Pont List items, assuming you know the name (in a string value) of the list you want to iterate through, and already have all the site code written?

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C#:

1. SPList interviewList = myWeb.Lists["listtoiterate"];

2. foreach (SPListItem interview in interviewList)

3. {

4. // Do Something

5. }

15) How do you return SharePoint List items using SharePoint web services?

In order to retrieve list items from a SharePoint list through Web Services, you should use the lists.asmx web service by establishing a web reference in Visual Studio. The lists.asmx exposes the GetListItems method, which will allow the return of the full content of the list in an XML node. It will take parameters like the GUID of the name of the list you are querying against, the GUID of the view you are going to query, etc.

Side Question: I got asked how I built queries with the lists.asmx web service. In order to build queries with this service, one of the parameters that the GetListItems method exposes is the option to build a CAML query. There are other ways to do this as well, but that was how I answered it.

16) When retrieving List items using SharePoint Web Services, how do you specify explicit credentials to be passed to access the list items?

In order to specify explicit credentials with a Web Service, you generally instantiate the web service, and then using the credentials properties of the Web Service object you use the System.Net.NetworkCredential class to specify the username, password, and domain that you wish to pass when making the web service call and operations.

*** Side Question: I got asked when you should state the credentials in code. You must state the credentials you are going to pass to the web service before you call any of the methods of the web service, otherwise the call will fail.

17) What is CAML, and why would you use it?

CAML stands for Collaborative Application Markup Language. CAML is an XML based language which provides data constructs that build up the SharePoint fields, view, and is used for table definition during site provisioning. CAML is responsible for rending data and the resulting HTML that is output to the user in SharePoint. CAML can be used for a variety of circumstances, overall is used to query, build and customize SharePoint based sites. A general use would be building a CAML query in a SharePoint WebPart in order to retrieve values from a SharePoint list.
18) What is impersonation, and when would you use impersonation?

Impersonation can basically provide the functionality of executing something in the context of a different identity, for example assigning an account to users with anonymous access. You would use impersonation in order to access resources on behalf of the user with a different account, that normally, that wouldn’t be able to access or execute something.