1.11 Content Types and Columns
The SharePoint 2010 content types feature provides a framework for
the storage of content within a SharePoint site or list. This framework
is expressed as a schema within which the designating features of a
specific type of content are specified, such as the name and
description of the content type. Additionally, each content type has an
associated set of columns that are bound to that type, and consequently
are bound to all content stored as a result of that type. For example,
assume that you want to store documents related to inventory within
your SharePoint site. To create a content type specific to inventory
documents, you would derive the root document content type, which will
come with its own predefined columns (Title, Author, CreatedBy, and so
on). Now assume that you name your new content type Inventory Document.
Then you will create or add new columns that are specific to the type
of document content you want to store using the new content type. For
example, you might want to include a column for inventory part number,
so that users uploading documents of this type will have the option—or
will be required—to enter a corresponding inventory part number. In
this case, you would create the structure illustrated in Figure 12.
Content types are created and managed within the site content type
gallery, and consequently they are available to all sites within the
site collection that are located below the site in which the content
type is defined. Columns may be defined at the list level (List
Columns) or at the site level (Site Columns) and are often referred to
as fields. When they are
defined at the site level, columns are also available to all sites
within the site collection that are located below the site in which the
site column is defined. Because content types use inheritance, derived
types by default contain all of the columns specified within parent
types. Changes made to type definitions anywhere within the tree can be
pushed down to the child types within the site and subsites as well as
to any lists within those sites that leverage those content types.
In earlier versions of SharePoint, the content type and column
architecture was limited by the fact that you could not share defined
content types and columns between site collections. This meant that, in
order to have the same types in multiple site collections, you had to
create the content types and columns in each new site collection
manually or resort to customization. SharePoint 2010 alleviates this
limitation by providing the ability to define content types in a
central location and have them automatically published to numerous site
collections. The Managed Metadata
Service provides a similar, yet even more flexible, capability for
columns. It is more flexible because, in addition to syndication of
columns, you can also define structured term sets, a kind of super
selector field, for which the selection criteria and options are
centrally managed and available anywhere the column is used.
Figure 13 shows an Inventory Document content type with a managed metadata column for the Inventory Part Number.
SharePoint 2010 provides new column types that you can use to define a content type. Figure 14 shows the Create New Column Settings page with a summary list of the out-of-the-box column types that are available.