Metadata Schemas

In Adobe Experience Manager (AEM) Assets, a metadata schema defines the layout of the properties page and the metadata properties displayed for assets that use the particular schema. Metadata properties include title, description, MIME types, tags, and so on. 

You can use the Metadata Schema Forms editor to modify existing schemas or add custom metadata schemas.

You can edit a newly-added or existing metadata schema form. The metadata schema form includudes the following:

• Tabs
• Form items within tabs.

You can map/configure these form items to a field within a metadata node in the CRX repository.

You can add new tabs or form items to the metadata schema form. The tabs and form items derived from the parent are in the locked state. You cannot alter them at the child level.

The Build Form tab lists form items that you use in your schema form. The Settings tab provides the attributes of each item that you select in the Build Form tab. The following table lists the form items available in the Build Form tab: 

To edit the properties of a metadata component on the form, click the component and edit all or a subset of the following properties in the Settings tab.

Field Label: The name of the metadata property that is displayed on the properties page for the asset.

Map to Property: This property specifies the relative path/name to the asset node where it is saved in the CRX repository. It starts with "./" because indicating that the path is under the asset's node.

The following are the valid values for this property:

• ./jcr:content/metadata/dc:title: Stores the value at the asset's metadata node as the property dc:title.
• ./jcr:created: Displays the jcr property at the asset's node. If you configure these properties on view properties, we recommend that you mark them as Disable Edit, because they are protected. Otherwise, the error "Asset(s) failed to modify" occurs when you save the asset's properties.

To ensure that the component is displayed properly in the metadata schema form, the property path should not include any spaces. 

Placeholder: Use this property to specify relevant placeholder text regarding the metadata property.

Required: Use this property to mark a metadata property as mandatory on the properties page.

Disable Edit: Use this property to make a metadata property uneditable on the properties page.

Show Empty Field In Read Only: Mark this property to display a metadata property on the properties page even if it has no value. By default, when a metadata property has no value, it is not be listed on the properties page.

Show list ordered: Use this property to display an ordered list of choices  

Choices: Use this property to specify choices in a list

Description : Use this property to add a short description for the metadata component.

Class: Object class the property is associated with.

Delete icon Click this icon to delete a component from the schema form.

If you select the Required option, you can search for assets missing mandatory metadata. From the Filters panel, expand the Metadata Validation predicate and select the Invalid option. The search results display assets missing mandatory metadata that you configured through the schema form.

If you add the Contextual Metadata component to any tab of any schema form, the component appears as a list in the properties page of assets to which the particular schema is applied. The list includes all other tabs except the tab to which you applied the Contextual Metadata component. Currently, this feature provides basic functionality to control the display of metadata based on the context.

To include any tab in the properties page in addition to the tab where the Contextual Metadata component is applied, select the tab from the list. The tab is added to the properties page.

Instead of specifying properties for the options in the Settings tab, you can define the options in a JSON file by specifying corresponding key-value pairs. Specify the path of the JSON file in the JSON Path field.

The schema editor lets you add or delete a tab. The default schema form includes the Basic, Advanced , IPTC, and IPTC Extension tabs, by default.

Click + to add a new tab on a schema form. By default, the new tab has the name "Unnamed-1." You can modify the name from the Settings tab. 

Click X to delete a tab.

AEM lets you delete custom schema forms only. It does not let you delete the default schema forms/templates. However, you can delete any custom changes in these forms.

To delete a form, select a form and click the Delete icon.

AEM Assets provides default forms for various MIME types out of the box. However, you can add custom forms for assets of various MIME types.

Create a new form under the appropriate form type. For example, to add a new template for the image/png subtype, create the form under the "image" forms. The title for the schema form is the subtype name. In this case, the title is "png."

You can use an existing template for a different MIME type. For example, use the image/jpeg form for assets of MIME type image/png.

In this case, create a new node at /etc/dam/metadataeditor/mimetypemappings in the CRX repository. Specify a name for the node and define the following properties:

AEM Assets maps the following MIME types and schema forms:

The Metadata Schema feature is available to administrators only. However, administrators can provide access to non administrators by modifying some permissions.

The non administrator should have Create, Modify, and Delete permissions on the /conf folder.

AEM Assets lets you define a variant of a metadata schema and apply it to a specific folder.

For example, you can define a variant of the default metadata schema and apply it to a folder. When you apply the modified schema, it overrides the original default metadata schema that is applied to assets within the folder.

Only assets uploaded to the folder to which this schema is applied will conform to the modified metadata defined in the variant metadata schema.

Assets in other folders where the original schema is applied continue to conform to metadata defined in the original schema.

Metadata inheritance by assets is based on the schema that is applied to the first-level folder in the hierarchy. In other words, if a folder does not contain subfolders, the assets within the folder inherit the metadata from the schema applied to the folder.

If the folder has a subfolder, the assets within the subfolder inherit the metadata from the schema applied at the subfolder level if a different schema is applied at the subfolder level. If, however, no schema or the same schema is applied at the subfolder level, the subfolder assets inherit the metadata from the schema applied at the parent folder level.

You can define mandatory fields at a folder level, which is enforced on assets that are uploaded to the folder. If you upload assets with missing metadata for the mandatory fields defined earlier, a visual indication for missing metadata appears on the assets in the Card view.