Metadata

When you query CMS (SaaS) content through Optimizely Graph, each content item exposes a _metadata field that you can cast to specialized types depending on the context: global contracts, base types, instance metadata for stand-alone items, item metadata for items embedded in content areas, or media metadata for assets. The following sections describe the fields available on each type.

Global contract types

A contract is an abstract type that other types can be composed of. Contracts can be user-defined, but Optimizely Graph also comes with a set of predefined contracts referred to as global contracts. Global contracts define common fields across multiple products and systems, which means there might be overlap of some of the fields between contracts and base types.

_Item

All types implement this contract. This contract defines the field _itemMetadata of type _Metadata.

The type _Metadata defines the following fields:

_AssetItem

All asset types, for example _Media, _Image, and _Video, implement this contract. This contract defines the field _assetMetadata of type _AssetMetadata.

The type _AssetMetadata defines the following fields:

_ImageItem

All image types, for example _Image, implement this contract. This contract defines the field _imageMetadata of type _ImageMetadata.

The type _ImageMetadata defines the following fields:

Base types

IContentMetadata

The common base type _Content, that all content types inherit, has the property _metadata of type IContentMetadata.

🚧

Important

Content can be displayed as stand-alone instances and as part of other content, for example inside content areas. Therefore _Content._metadata is of type IContentMetadata rather than ContentMetadata.

IContentMetadata can be cast (with fragments) to InstanceMetadata, ItemMetadata, and MediaMetadata, see below.

The type IContentMetadata defines the following fields:

InstanceMetadata

For stand-alone instances, _metadata can be cast to InstanceMetadata, which implements IContentMetadata but adds more fields. The following is an example of a query that casts to InstanceMetadata:

query RouteSegmentQuery {
  _Page {
    items {
      _metadata {
        displayName
        ... on InstanceMetadata {
          routeSegment
        }
      }
    }
  }
}

The type InstanceMetadata defines the following fields:

ItemMetadata

For instances embedded in content areas, _metadata can be cast to ItemMetadata, which implements IContentMetadata but adds more fields. The following is an example of a query that casts to ItemMetadata:

query ContentAreaQuery {
  _StandardPage {
    items {
      ContentAreaProperty {
        ... on TeaserBlock {
          _metadata {
            ... on ItemMetadata {
              displayOption
            }
          }
        }
      }
    }
  }
}

The type ItemMetadata defines the following fields:

MediaMetadata

For media content items, _metadata can be cast to MediaMetadata, like the following:

query MimeTypeQuery {
  _Media {
    items {
      _metadata {
        displayName
        ... on MediaMetadata {
          mimeType
        }
      }
    }
  }
}

The type MediaMetadata defines the following fields: