Content Metadata properties
Describes metadata interfaces and metadata properties that you can define on content models.
EPiServer.Core.IContentData
is the base interface that content models implement. All content types, except BlockData
, also implement the EPiServer.Core.IContent
interface; the interface is required for a content instance to have a unique ID and its own lifecycle (that is, it can be loaded or saved individually). Through the EPiServer.IContentRepository
, you can perform CRUD (Create, Read, Update, Delete) operations on content instances implementing EPiServer.Core.IContent
, for example, listing and move.
There are also many additional metadata interfaces a content type can implement that define its characteristics. Here is a list of the existing metadata interfaces, with a description of each interface's purpose and which properties it contains.
UsageÂ
Because some of the interfaces are optional, a recommended pattern when working with a "general" IContent
instance is to use the is or as operators to check if the instance implements an interface, as in this example:
public static CultureInfo Language(this IContent content) {
if (content == null) throw new ArgumentNullException(nameof(content));
return (content is ILocale locale) ? locale.Language : CultureInfo.InvariantCulture;
}
public static bool IsModified(this IContent content) {
if (content == null) throw new ArgumentNullException(nameof(content));
var modifiedTrackable = content as IModifiedTrackable;
return modifiedTrackable == null || modifiedTrackable.IsModified;
}
Shared blocks
BlockData
does not implement IContent
, while shared block instances still have their own identity defined on IContent
. This is accomplished so that during runtime, when a shared block instance is created (for example, through a call to IContentRepository.GetDefault<T>
where T is a type inheriting from BlockData
), the CMS creates a new .NET type inheriting T using a technique called mixin where the newly generated subclass will implement some extra interfaces (including IContent
).
That means that a shared block instance of T will implement IContent
while an instance of T that is a property on a Page will not.
IContentData
Base interface for content models. It contains a backing PropertyDataCollection
that is used when loading or saving data from the database.
Member | Type | Description |
---|---|---|
Property  | PropertyDataCollection | Contains backing data for properties used by the content instance. |
IContent
You can individually load or save base interfaces for content models with an identity. IContent
inherits IContentData
. Note that ContentLink.ID
and ContentGuid
is the same for language branches for a content item. So the combination of ContentLink
or ContentGuid
and ILocale.Language
uniquely specifies the content instance (given that the content implements ILocalizable
). Built-in base content types, (except BlockData
), implement IContent
. Shared block instances implement IContent
(and most other metadata interfaces) at runtime.
Member | Type | Description |
---|---|---|
Name  | string | The name of the content instance. |
ContentLink | ContentReference | The identifier of the content instance. If the instance represents a specific version, WorkID specifies an optional version ID. |
ContentGuid | Guid | A GUID-based identifier for the content instance. |
ParentLink | ContentReference | The parent identifier (in a tree structure) for the content instance. |
ContentTypeID | int | An identifier that specifies which content type the content is an instance of. |
IsDeleted | bool | Indicates if the content instance is in the wastebasket. |
Property | PropertyDataCollection | Inherited from IContentData . |
IVersionable
An optional interface for content that supports different versions for each language branch. There can only be at most one version published at each time. All built-in types, except ContentFolder
, implement IVersionable
. See Content versions for information regarding versions.
Member | Type | Description |
---|---|---|
Status | VersionStatus | Specifies the status of the content version. |
IsPendingPublish | bool | Specifies if there is any published version for the current language branch. |
StartPublish | DateTime? | Optional value that specifies when the content is/was published. |
StopPublish | DateTime? | Optional value that specifies when the content is/was depublished. |
ILocale
An optional interface for content that specifies which language a specific content instance has. All built-in types except ContentFolder
implements ILocale
.
Member | Type | Description |
---|---|---|
Language | CultureInfo | Specifies the language of a content instance. CultureInfo.InvariantCulture means that the content instance is not culture-specific. |
ILocalizable
An optional interface for content that support multiple language branches. Inherits ILocale
. Built-in types, (except ContentFolder
 and MediaData
), implement ILocalizable
.
Member | Type | Description |
---|---|---|
Language | CultureInfo | Inherits from ILocale . |
MasterLanguage | CultureInfo | Specifies which language version that contains the none language-specific properties. |
ExistingLanguages | IEnumerable<CultureInfo> | Specifies existing language branches for this content. |
IReadOnly and IReadOnly
An optional interface for content that support read-only instances. It is highly recommended that content types implement IReadOnly
, which ensures the integrity of the content instances when instances are served from the cache and hence reused across different requests. Built-in base content classes implement IReadOnly
.
Member | Type | Description |
---|---|---|
IsReadOnly | bool | Specifies if the current instance is read-only. |
void MakeReadOnly() | Method | Makes an instance read-only. |
object/T CreateWritableClone() | Method | Creates a writable clone from a read-only instance. |
IModifiedTrackable
An optional interface for content instances that support modified tracking. There is a high-performance gain during save operations if you use IModifiedTrackable
because only data that has actually changed needs to be persisted. Built-in base content classes implement IModifiedTrackable
.
Member | Type | Description |
---|---|---|
IsModified | bool | Specifies it the current instance is modified. |
void ResetModified() | Method | Sets the content instance in a non-modified state. |
IChangeTrackable
An optional interface for content instances that support tracking of changes. Built-in base content classes implement IChangeTrackable
.
Member | Type | Description |
---|---|---|
IsModified | bool | Specifies if the current instance is modified. |
void ResetModified() | Method | Sets the content instance in a non-modified state. |
IContentSecurable
An optional interface for content instances that support access checks. Built-in base content classes implement IContentSecurable
.
Member | Type | Description |
---|---|---|
IContentSecurityDescriptor GetContentSecurityDescriptor() | Method | Gets the security descriptor for the content instance where access rights can be checked. |
IRoutable
An interface that content items that should be routable through a content URL should implement. Built-in base content classes, except shared blocks, implement IRoutable
.
Member | Type | Description |
---|---|---|
RouteSegment | string | Specifies the route segment that is used for the content instance in the hierarchical content url. |
ICategorizable
An interface that content items that should be possible to categorize should implement. Built-in base content classes, except content folders, implement ICategorizable
.
Member | Type | Description |
---|---|---|
Category | CategoryList | A list of all categories that this content instance is categorized as. |
IInitializableContent
If you should add default values when you create an instance of the content type, you can optionally implement the IInitializableContent
interface for content items.
Member | Type | Description |
---|---|---|
void SetDefaultValues(ContentType contentType) | Method | Called when a new instance of the content type is created. |
IExportable
An optional interface that specifies how a content instance should be handled during export.
Member | Type | Description |
---|---|---|
ShouldBeImplicitlyExported | bool | Specifies whether this instance should be implicitly added to the export package when referenced by some exported entity. |
Updated 5 months ago