SharePoint Quick Start FAQ: Part III

Introduction

Previous SharePoint QuickStart FAQ

• Quick Start FAQ Part 1 :- 11 basic FAQ questions , must for every new comer. It's a the basic Quick Start FAQ tutorial which talks about What is SharePoint ,WSS,MOSS,Site/Site collection , Virtual Path provider and then ends with explaining SitePages and Application pages First Article of Share Point
• Quick Start FAQ part 2:- This is the second part in the series which explains the ready made functionalities, custom pages,deploying/activating/deactivating features and lot. Second Part

How can we provision page template and page instances?

Before we move ahead with this question let's first define provisioning. Provisioning is a fancy name of making something available. So let's first create a page template using the 'Default.Master' and the see how we can provision this page on the website.. So below is the code snippet where we can create a master page from the 'Default.Master'.

In order to use the template we need to create an instance in the SharePoint runtime. Creating a instance of the template in the SharePoint runtime is termed as provisioning.

We need to use the 'Module' and 'File' tag to provision an instance of the template page. This is done in the 'ElementManifest.XML' file. Below is the code snippet of 'ElementManifest.XML' file which has the module tag with a file tag specifying what the URL page name is? This is the same template which we had shown on the top. 'PageA.aspx' is the instance name and 'MyPage.aspx' is the physical page name of the template page.

The type attribute has two values 'Ghostable' and 'GhostableInLibrary'. If you want to provision a resource inside a document library then you need to specify 'GhostableInLibrary'. If you do not want to provision a resource inside a document library then you need to specify 'Ghostable' value. For the current exercise we have given the value as 'Ghostable'.

A note the path attribute has the page in the 'MyPath' folder.

As said previously we also need to define the feature.xml file which has the receiver class and the element manifest pointing to the elementmanifest.xml file.

In the receiver class we will add menu items in the quick launch nodes. So in the activation event we will add a link which will activate this feature and in the deactivation event we will remove this feature.

So in the activation event we first need to get reference to the SpSite object using the URL.

From the SpSite object we get the 'SpWeb' object.

From the 'SpWeb' object we get reference to all node collection of the Quick launch menu.

Now we create a menu of the page.

Add the menu to the quick launch node.

In the deactivation event we will remove the link.

Now that we have done with creating the two xml files and the class which will handle the feature events , use stsadm utility to register the feature. Once you have registered it you should see the feature in the feature list display. We have named the feature as 'Provision' so you can see the 'Provision' feature.

Once you activate the feature you should see the 'Quest' link which points to the template instance page 'PageA.aspx'. If you disable the feature you will not be able to browse the page instance.

Why customized pages are parsed using no-compile mode?

We had discussed previously two types of pages site pages and application pages. Site pages can be customized while application pages are standard pages like 'settings.aspx' which is common across sites.

When a user customizes a site page a customized version of the site page is saved in the content database. This provides lot of flexibility but it has its own disadvantages. We can customize site pages using 'SharePoint Designer'.

Now let's try to understand how a customized site page which is saved content is processed. Customized site pages are processed in six steps:-

• Step 1:- The user requests a customized page.
• Step 2:- SharePoint HTTP handler i.e. 'SPVirtualPathProvider' picks the request and shoots a query to the content database to fetch the page.
• Step 3:- Site page is retrieved and sent to the SharePoint handler.
• Step 4:- The site page data is given to the ASP.NET parser. Please note this ASP.NET parser is not the one which IIS uses. This is made especially for SharePoint.
• Step 5:- Parser parses and gives the output to the handler.
• Step 6:- Handler finally gives the output back to the client.

Below is the reason why non-compiled pages are more efficient then compiled pages.

Compiled pages Non-Compiled pages
Once the compiled ASP page DLL is loaded it gets unloaded only when the App Domain gets recycled. It can be loaded and unloaded. In this scenario the memory management is more efficient.

What is safe mode processing and Safe Controls?

Any customized page is parsed using safe mode processing. This parsing brings in security. Safe mode processing guarantees that there is no inline script in the customized page. In other words safe mode processing disallows in-line script because a hacker can mount attack using in-line script. If you try to run in-line script on customized page you will get error 'Code blocks are not allowed in this file'.

In case you still want to run in-line script in customized pages you need to specify 'AllowServerSideScript=true' in the 'SafeMode' tag section in web.config file.

Safe controls help us define which controls the customized pages will have. Customized pages can only have controls which are defined in the web.config file in the 'SafeControls' tag. For instance in the below code snippet we have defined that customized pages can use controls from 'Microsoft.SharePoint.WebControls'.

Can you explain WSS model?

In order to understand WSS model we need to first understand different types of services used by SharePoint. SharePoint uses two major services in is IIS which is a non-data service and the other is SQL Server i.e. database related services.

SharePoint was designed from the view point that it can be used in web farms. So lets first visualize web farms and then we will try to understand how SharePoint visualized web farms.

Below figure shows two aspects one a normal visualization of a web farm and other the SharePoint view point. In our normal view (i.e. the left hand side of the image) we can think of farms having servers and servers having the two services (i.e. IIS and DB service). When SharePoint visualizes the farm infrastructure it's a bit different.

SharePoint visualizes the farm infrastructure in terms of database services and non-database services. So it visualizes database services attached to servers and non-database services like IIS differently.

Note: - We are not sure why there is a change in visualization.

So let's visualize how the WSS object model of SharePoint is seen.

• The parent object in the SharePoint hierarchy is the SPfarm object.
• SPFarm will have collection of server objects i.e. the 'SPServer' objects.
• 'SPServer' objects further have 'SPDatabaseServiceInstance' object.
• 'SPDatabaseServiceInstance' has a 'SPContentDatabase' object instance.
• From the 'SPFarm' you can also browse to services on farm level. 'SPFarm' has 'SPService' collection.
• 'SPService' in turn allow us to browse through IIS application i.e. 'SPWebApplication'.
• 'SPWebApplication' has site collection which in turn has site object which can be browsed using 'SPSite' object.

Now let's understand the object hierarchy below the 'SPSite'. 'SPSite' / Site belong to site collection. In other words one site collection can have many sites inside it. Site will have lists and list will have fields.

Below is the code snippet which takes the Farm object , browses through all its services , using the service object browses through all its web application and then using web application browses through all sites.