Subject: SAP-Fiori-Elements
Field: SAP
In SAP Fiori Elements, annotations play a pivotal role in defining how data from backend services is rendered on the user interface. The UI5 Annotation Model bridges the backend metadata and the frontend UI by interpreting annotations embedded in CDS views or external annotation files. Understanding how to configure and use this annotation model is key to harnessing the full power of SAP Fiori Elements for building rich, dynamic, and standardized enterprise applications.
This article explores the concepts, configuration steps, and practical usage of the Fiori Elements UI5 Annotation Model.
The UI5 Annotation Model is a client-side representation of metadata and annotations that come from the backend OData service. It:
Effectively, it acts as a translator between backend metadata and Fiori Elements UI templates.
Annotations can be supplied from multiple sources:
CDS View Annotations:
Embedded directly in CDS views using ABAP syntax (@UI.lineItem, @UI.identification, etc.). These are published with the OData service metadata.
External Annotation Files:
XML or JSON files that augment or override CDS annotations without modifying the backend. Useful for customizing standard apps or multi-tenant environments.
Annotations via Metadata Extensions:
Extensions on OData metadata documents to enhance or add annotations post-service publication.
When a Fiori Elements app starts:
$metadata).This process enables powerful model-driven UI rendering without explicit coding for UI controls.
By default, if your CDS views have embedded annotations and @OData.publish: true is enabled, the annotations are included in the OData metadata. The UI5 framework automatically consumes them — no additional configuration is required.
To reference external annotation files:
sap.ui5 section:"sap.ui5": {
"models": {
"": {
"dataSource": "mainService",
"settings": {
"annotations": [
"annotationFile.xml"
]
}
}
}
}
"dataSources": {
"mainService": {
"uri": "/sap/opu/odata/sap/Y_SERVICE_SRV/",
"type": "OData",
"settings": {
"annotations": ["annotations/annotationFile.xml"]
}
},
"annotationFile.xml": {
"uri": "localService/annotations/annotationFile.xml",
"type": "ODataAnnotation",
"settings": {
"localUri": "annotations/annotationFile.xml"
}
}
}
This allows adding or overriding annotations on top of those delivered by CDS.
Advanced scenarios may require programmatically adding or manipulating annotations via SAPUI5 APIs, although this is less common.
Once configured, annotations influence UI behavior in various ways:
Developers can extend standard behavior by adding annotations like:
@UI.lineItem for table columns@UI.fieldGroup for grouping fields@UI.selectionField for filters@Chart annotations for analytical visualsThe SAP Fiori Elements UI5 Annotation Model is a fundamental enabler of model-driven UI development. Properly configuring and leveraging this model empowers SAP developers to create feature-rich, adaptable, and consistent Fiori applications with minimal UI coding. Understanding the annotation model's architecture and configuration options is essential for maximizing productivity and maintaining UI quality in SAP Fiori Elements projects.