Microsoft SharePoint 2007 Technologies

2.4 Storage 29

Chapter 2

2.4 Storage

The core storage mechanism within a site is that of lists and libraries, with

libraries just being a special form of list. Lists can be used for whatever pur-

pose you see fit; some standard lists such as Announcements, Contacts, and

Events ship out of the box and are contained within various site definitions.

A list is defined in terms of columns (AKA metadata or properties); these col-

umns can be of differing types (string, date, number, etc.) and can have val-

idation rules applied to them to maintain consistent and relevant data. WSS

3.0 introduces many list enhancements, including the ability to have multi-

valued and append-only columns—the latter being very useful for tracking

changes made to items. You can also define your own custom columns that

could, for example, validate the data against a back-end enterprise applica-

tion or ensure the data is of a particular format like a Social Security Num-

ber. Different views can be applied to lists, allowing flexibility in the display

of data within a list (for example you can group, sort and filter the items in a

list via a view), and you can add your own custom views as necessary.

Different types of libraries are available within WSS 3.0, with the main

one being a document library (there are also picture and form libraries avail-

able out of the box). The main difference between a library and a list is that

one of the columns in the library contains the physical document itself.

There are many ways to interact with content stored in lists and libraries.

The primary vehicle from an enduser’s perspective is the browser, where con-

tent is typically displayed via Web Part pages and new items can be created

directly in a list or library (you can upload documents through the browser

into a library). The rich API and Web services that WSS 3.0 supports enable

many other forms of interacting with the content within a site. For example,

library documents can be opened and saved directly from an Office 2007

application such as Word or Excel, and Outlook 2007 can be used as a smart

client to WSS 3.0 content, facilitating the reading and writing of list items

directly from Outlook! Indeed, as we will see later, you can even e-mail con-

tent into a list or library.

Lists and libraries existed in WSS 2.0 and served their purpose fairly

well. However, they had some major restrictions that would have prevented

the rich set of solutions areas being delivered, had major enhancements not

been made. These enhancements fall into the metadata, administration,

security, and versioning areas. Let’s take a look at each of these.

2.4.1 Metadata—Introducing Content Types and

Site Columns

A big disappointment for many customers who moved from SPS 2001 to SPS

2003 was the removal of document profiles. These were essentially definitions

30 2.4 Storage

of metadata for different types of documents, enabling you to support multi-

ple profiles within a single document library. In SPS 2003 (and WSS 2.0),

each library and list can only have one metadata definition associated with it

(essentially the list of columns that the list/library supports), and this therefore

dictated that multiple document libraries be created to support different doc-

ument types. This was clearly an inconvenience for many situations, not least

because it meant existing filing systems had to be redesigned and single docu-

ment libraries split into multiple to support the same scenarios.

WSS 3.0 introduces content types through which multiple metadata defi-

nitions can be associated with a single library or list. This is obviously a good

thing, but it will provide some challenges in migrating to WSS 3.0 if multi-

ple libraries need to be consolidated into a fewer number. Content types are

used for many different purposes in SharePoint 2007—defining page lay-

outs, controlling workflow on a particular item, and creating search scopes—

and reveal themselves in many different places, such as when navigating a

list/library through the browser or via the document properties pane within

Office 2007 applications. As an example, look at Figure 2.20, where we have

defined a new content type called Spy Movies that has a simple piece of

metadata associated with it called genre. Here we are looking at that meta-

data through the browser and through Word 2007 for a document that has

been associated with the content type Spy Movies.

Content types are categorized into groups for ease of management, and

you can create new groups to suit your own needs. Each site in a collection

Figure 2.20

Metadata and

content types.