Micorosoft Sharepoint 2013 : SharePoint Metadata Types (part 2) - Content Types

Content Types

Content types provide content owners with the powerful capability to manage metadata content in SharePoint. The basic anatomy of a content type is that of a group of site columns (fields) that represents a content object in the content management system. For example, a content type may include several site columns that constitute a person’s contact details—name, address, telephone, and so on.

Understanding the use of content types is important when discussing content and metadata management in SharePoint, because SharePoint uses content types practically everywhere there is categorization or definition of content schema. The following are some of the areas in which SharePoint employs the use of content types:

• Column definitions in lists and list items
• Document metadata (document properties) in document libraries
• Content fields in publishing pages
• External data definition via Business Connectivity Services
• Search filtering and scopes

Content types incorporate inheritance in the SharePoint Metadata System, which provides for greater levels of flexibility in metadata modeling and abstraction of content definition. Content owners may define basic content types and then subclass these content types to define new content types with greater refinement of metadata.

As an example, Table 1 defines a Bio-Page content type for a publishing page, containing biographic information for staff members on an organization’s public web site.

When coupling this content type with a page layout, SharePoint allows content owners to define new page instances, with the defined site columns, to contain data about a staff member. The page layout defines HTML markup, which tells SharePoint how to render the page content. The actual content of the page resides in a list item that is the page instance in a Pages document library.

The organization hosting the web site decides one day to provide a new advanced biographic page type that not only shows the standard details on a staff member, but also includes education information. To achieve this new advanced Bio-Page implementation, the site designers provide a new page layout, based on the standard Bio-Page layout, with placeholders for the new education fields. Rather than create a completely new content type to associate with the page layout, SharePoint allows the content owners to subclass the standard Bio-Page content type and add the additional fields.

Using content type inheritance, users may create elaborate metadata models with basic content types at the root of the model, and more specification of content types throughout the branches of the model. Figure 3 illustrates the concept of content type inheritance. Both the MSA and SOW content types exist as separate document content types, which inherit from the common Contract content type parent. The Contract content type inherits from the stock Document content type, which itself inherits from the stock Item content type. All the columns in each content type of the chain exist in the leaf content type, so the SOW content type includes the following columns: Project, Contact, Customer, Size, and File name.

SharePoint defines a basic content type, called Item, which contains the site column Title. Examples of content types that subclass the Item content type include Document, which adds the Name column for the file name, and Announcement, which includes columns for the Body of an announcement and a date field for Expiration. SharePoint ships with many stock content types in Basic and Team site definitions, and even more in Publishing site definitions.

As it does with site columns, SharePoint maintains a list of content types in a site. The following steps demonstrate how to create a new content type for our Bio-Page (Table 1):

1. From the root of the site collection, click the gear icon.
2. Click the Site Settings menu item.
3. On the Site Settings page, under Galleries, click the Site Content Types link.

SharePoint shows all the content types defined in the site collection, as in Figure 4. There you can see that each content type belongs to a group and specifies both a parent and the source location in the site collection hierarchy.

1. Click the Create link at the top of the page.
2. Give the new content type a name and a description.
3. Specify the parent content type. SharePoint helps you out here by providing a drop-down to restrict the choices by group.
4. Provide either an existing group or a new group name to file the new content type.
5. Click the OK button.

SharePoint should now show you the Settings page (Figure 5) for the content type created. SharePoint allows you to attach workflow and information management policy, change general settings for the content type in the Settings section of this page, and much more.

1. Scroll to the Columns section.
2. You should see those columns present from the parent content type. In my case, I inherited from the Item content type, and so I see the Title column only.
3. SharePoint indicates the parent content type under the Source heading (linked). You may click this link to visit the settings of the parent content type.
4. Click the Add from existing site columns link to navigate to a page to choose from existing site columns at the current site and above (if not at the root of the site collection).
5. Click the Add from new site column link to create a new site column for the content type—any new site column created resides in the Site Columns Gallery of the current site.

Content types provide for powerful, yet flexible definition of the metadata. Like most things in life, this power and flexibility comes with caveats, as follows:

• You cannot delete a content type once it is in use by a container, list item, or page, or inherited by another content type.
• Once you create a content type, you may not change its inheritance relationship with the parent. You must delete the content type and re-create it to inherit from a different content type. This restriction, coupled with the first caveat, can make for difficulty in restructuring an existing metadata model in use by content. Design your model with flexibility at the onset.
• Deleting an inherited column from a content type is ill advised. Instead, make the column hidden.
• Avoid modifying stock content types. Instead, create a new content type and add customization to your new type—content owners expect standard behavior when using stock content types.
• You may not delete any content type deployed via a custom-developed feature.

Content types not only define metadata for documents in libraries and list items in lists, they also provide additional functionality, outlined in Table 2.

Of course, Table 2 is not exhaustive. Content types play a major role in SharePoint and provide the central core for many data-associated functions. Content types provide data portability in that each content type describes data—the schema—such that you can use these content types anywhere you wish to apply specific functionality to certain data types.