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.
Edit various metadata properties under the various tabs. However, you cannot modify the asset type in the properties page.
To modify the MIME type for an asset, use a custom metadata schema form or modify an existing form. See Editing Metadata Schema Forms for more information. If you modify the metadata schema for a certain MIME type, the properties page layout for assets with the current MIME type and all asset subtypes are modified. For example, modifying a jpeg schema under default/image only modifies the metadata layout (asset properties) for assets with MIME type IMAGE/JPEG. However, if you edit the default schema, your changes modify the metadata layout for all types of assets.
To view a list of forms/templates, click the AEM logo and then navigate to Tools > Assets > Metadata Schemas.
AEM provides the following templates out of the box:
The following child forms inherit the properties of the default form:i. image: Schema form for assets with the MIME type "image", for example, image/jpeg, image/png, and so on.The "image" form has the following child form templates:a. jpeg: Schema form for assets with sub type jpeg.b. tiff: Schema form for the assets with sub type tiff.ii. application: Schema form for assets with MIME type "application", for example application/pdf, application/zip, and so on.a. pdf: Schema form for assets with sub type pdf.iii. video: Schema form for assets with MIME type "video", such as video/avi, video/mp4 and so on.
- default: The base metadata schema form for assets.
- collection: Schema form for collections
- contentfragment: Schema form for content fragments
- forms: This schema form relates to Adobe Experience Manager Forms
To view the child forms of a schema form, click/tap the schema form name.
If you upgrade from AEM 6.1 to AEM 6.3, custom metadata schemas in AEM 6.1 automatically migrate to AEM 6.3 only if the metadataSchema property includes index definitions. If the metadataSchema property is not indexed, the upgrade process skips migrating custom metadata schemas, and logs the following warning:
Cannot update metadata schema property for the folder item at ****. Make sure metadataSchema property is properly indexed before the launch of this upgrade task.
To migrate the missed metadata schemas, launch the upgrade task again after indexing the metadataSchema property.
To add new tabs and form items within tabs, you can edit a newly-added or an existing metadata schema form. You can map/configure these form items to a field within a metadata node in the CRX repository. However, you cannot edit the tabs and form items that are derived from the parent as these are in a locked state.
The Build Form tab lists form items that you use in your schema form to create metadata fields. The Settings tab provides the attributes of the selected item. The following table lists the form items that are available in the Build Form tab.
|Section Header||Add a section heading for a list of common components.|
|Single Line Text||Add a single line text property. It is stored as a string.|
|Multi Value Text||Add a multi value text property. It is stored as a string array.|
|Number||Add a number component.|
|Date||Add a date component.|
|Dropdown||Add a dropdown list.|
|Standard Tags||Add a tag.|
|Hidden Field||Add a hidden field. It is sent as a POST parameter when the asset is saved.|
|Asset Referenced By||Add this component to view list of assets referenced by the asset.|
|Asset Referencing||Add to display a list of assets that reference the asset.|
|Products References||Add to show the list of products linked with the asset.|
|Asset Rating||Add to display options for rating the asset.|
|Contextual Metadata||Add to control the display of other metadata tabs in the properties page of assets|
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.
The Hidden Field component does not include these attributes. Instead, it includes properties, such as attributes Name, Value, Field Label, and Description. The values for the Hidden Field component are sent as a POST parameter whenever the asset is saved. It is not be saved as metadata for the asset.
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
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.
After you delete custom changes to a default form, the Lock icon reappears before it on the Metadata Schema interface to indicate that the form reverted to its default state.
You cannot delete the out of the box metadata schema forms in AEM Assets.
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:
|exposedmimetype||Name of the existing form to be mapped||String||image/jpeg|
|mimetypes||List of MIME types that use the form defined in the exposedmimetype attribute||String||image/png|
|Schema Form||MIME type(s)|
|video/avi||video/avi, video/msvideo, video/x-msvideo|
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.
(Optional) Access http://[server]:[port]/system/console/components/. Configure and enable com.day.cq.dam.core.impl.MissingMetadataNotificationJob component that is disabled by default. Set a frequency at which AEM checks for the validity of metadata on the assets.
This configuration adds a property hasValidMetadata to jcr:content of assets. Using this property, AEM can filter results in a search.
If an asset is added after the scheduled check, the asset is not flagged with hasValidMetadata until the next scheduled check. The assets does not appear in intermediate search results.
The metadata validation checks are resource intensive and may impact the performance of your system. Schedule the checks accordingly. If the server cannot cope up with the load, try disabling this job.