"Implementing Dynamic Feature Control in SAP RAP to Make a Field Read-Only"

This article explains how to make a field read-only in SAP RAP based on the value of another field. The author sets up a basic RAP application structure, defines an interface view, projection view, and behavior definition. The scenario covered is making the VBTYP field read-only based on the value of the AUART field. The author implements dynamic feature control for the field VBTYP and uses the get_instance_features method of the behavior implementation class to make the field read-only.

In SAP RAP (Rapid Application Platform), making a field read-only based on the value of another field is a common requirement for customizing user interfaces. This article explains how to achieve this by setting up a basic RAP application structure and defining the necessary views and behaviors.

Setting Up the Basic RAP Application Structure

1. Create a New RAP Application:
- Start by creating a new RAP application in the SAP RAP development environment.

2. Define the Interface View:
- Create an interface view that includes the fields you want to control. In this scenario, the fields are `VBTYP` (Value Type) and `AUART` (Application Type).

Defining the Projection View

1. Create a Projection View:
- Define a projection view that maps the interface view to the data model. This view will be used to display the data in the application.

Implementing Behavior Definition

1. Create a Behavior Definition:
- Define a behavior that will control the read-only state of the `VBTYP` field based on the value of the `AUART` field.

Making the Field Read-Only

1. Dynamic Feature Control:
- Implement dynamic feature control for the `VBTYP` field. Use the `get_instance_features` method of the behavior implementation class to make the field read-only.

2. Behavior Implementation Class:
- In the behavior implementation class, override the `get_instance_features` method to check the value of the `AUART` field. If the value meets the criteria (e.g., certain application types), set the `VBTYP` field to read-only.

Example Code

```javascript
// Example behavior implementation class
function BehaviorImplementation() {
// Override the get_instance_features method
this.get_instance_features = function(instance) {
var features = {};
// Check the value of the AUART field
if (instance.AUART === 'some_value') {
// Make the VBTYP field read-only
features.VBTYP = { readOnly: true };
}
return features;
};
}
```

Conclusion

By following these steps, you can dynamically control the read-only state of a field in SAP RAP based on the value of another field. This approach ensures that your application's user interface is customized to meet specific business requirements, enhancing user experience and data integrity.

References

Mar Vista U.S. Quality Q3 2025 Top Contributors And Detractors^[1] https://seekingalpha.com/article/4829034-mar-vista-us-quality-q3-2025-top-contributors-detractors