altTypes produces registerEnum errors

[nkappler]

OpenUI5 version: 1.120.2

Using UI5 Controls as altTypes produces an error, as if the Control would be an enum

This example:

sap.ui.core.Control.extend("XYZ", {
    metadata: {
        aggregations: {
            button: {
                type: "sap.m.Button",
                altTypes: ["sap.m.MenuButton"]
            }
        }
    }
});

is functionally identical to:

sap.ui.core.Control.extend("XYZ", {
    metadata: {
        aggregations: {
            button: {
                type: ["sap.m.Button", "sap.m.MenuButton"]
            }
        }
    }
});

however, the first one produces the following error and the second doesn't The type 'sap.m.MenuButton' was accessed via globals. Defining enums via globals is deprecated. Please require the module 'sap/ui/base/DataType' and call the static 'DataType.registerEnum' API. -

[codeworrior]

Both usages are not supported. Aggregations don't support multiple (managed object) types. Either a single type or an interface can be used.

The altTypes are meant to specify a primitive alternative, e.g. like string for the tooltip aggregation. The given type name must be resolvable via the DataType.getType API. In UI5 1.x, this API was able to resolve a name as a global name to create an enum type from it. In UI5 2.x this is no longer supported as we abandon global names. That's the background of the - often misleading - error message.

We've meanwhile improved this error message in 1.121. It now reads:

[DEPRECATED] The type '${sTypeName}' was accessed via globals. Defining types via globals is deprecated. In case the referenced type is an enum: require the module 'sap/ui/base/DataType' and call the static 'DataType.registerEnum' API. In case the referenced type is non-primitive, please note that only primitive types (and those derived from them) are supported for ManagedObject properties. If the given type is an interface or a subclass of ManagedObject, you can define a "0..1" aggregation instead of a property

This still does not reflect the usage in altTypes, but they're basically used to make single aggregations alternatively behave like properties.